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Agwuegbo CC, Antia AU, Shamaki GR, Bob-Manuel T. Controversies related to renal artery denervation and devices. Curr Opin Cardiol 2024; 39:244-250. [PMID: 38567924 DOI: 10.1097/hco.0000000000001146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
PURPOSE OF REVIEW This review article discusses the controversies, strengths, and limitations of the current literature on renal artery denervation in the management of resistant hypertension, as well as the future directions of this intervention. RECENT FINDINGS There have been conflicting data from the different randomized control trials assessing the efficacy of renal artery denervation in the management of resistant hypertension. SUMMARY Renal artery denervation is achieved by ablating the sympathetic nerves surrounding the renal arteries using endovascular ultrasound, radiofrequency, or alcohol. Our review article highlights that renal artery denervation is generally effective in improving blood pressure in patients with resistant hypertension. The Food and Drug Administration (FDA) has recently approved the ReCor Medical Paradise system, and the Symplicity Spyral RDN systems for renal artery denervation.
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Affiliation(s)
| | | | | | - Tamunoinemi Bob-Manuel
- Division of Cardiovascular Diseases, University of Tennessee Health Science Center, Memphis, Tennessee, USA
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2
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Nishimoto M, Griffin KA, Wynne BM, Fujita T. Salt-Sensitive Hypertension and the Kidney. Hypertension 2024; 81:1206-1217. [PMID: 38545804 DOI: 10.1161/hypertensionaha.123.21369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
Salt-sensitive hypertension (SS-HT) is characterized by blood pressure elevation in response to high dietary salt intake and is considered to increase the risk of cardiovascular and renal morbidity. Although the mechanisms responsible for SS-HT are complex, the kidneys are known to play a central role in the development of SS-HT and the salt sensitivity of blood pressure (SSBP). Moreover, several factors influence renal function and SSBP, including the renin-angiotensin-aldosterone system, sympathetic nervous system, obesity, and aging. A phenotypic characteristic of SSBP is aberrant activation of the renin-angiotensin system and sympathetic nervous system in response to excessive salt intake. SSBP is also accompanied by a blunted increase in renal blood flow after salt loading, resulting in sodium retention and SS-HT. Obesity is associated with inappropriate activation of the aldosterone mineralocorticoid receptor pathway and renal sympathetic nervous system in response to excessive salt, and mineralocorticoid receptor antagonists and renal denervation attenuate sodium retention and inhibit salt-induced blood pressure elevation in obese dogs and humans. SSBP increases with age, which has been attributed to impaired renal sodium handling and a decline in renal function, even in the absence of kidney disease. Aging-associated changes in renal hemodynamics are accompanied by significant alterations in renal hormone levels and renal sodium handling, resulting in SS-HT. In this review, we focus mainly on the contribution of renal function to the development of SS-HT.
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Affiliation(s)
- Mitsuhiro Nishimoto
- Department of Internal Medicine, Division of Nephrology & Hypertension, International University of Health and Welfare Mita Hospital, Tokyo, Japan (M.N.)
| | - Karen A Griffin
- Department of Medicine, Renal Disease & Hypertension, Loyola University, Chicago, IL (K.A.G.)
- Veteran's Administration, Nephrology, Edward Hines Jr. VA Hospital (K.A.G.)
| | - Brandi M Wynne
- Department of Internal Medicine, Nephrology & Hypertension, Department of Nutrition and Integrative Physiology, and Immunology, Inflammation and Infectious Disease Initiative (B.M.W.), University of Utah, Salt Lake City
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science & Technology, The University of Tokyo, Japan (T.F.)
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Hao M, Lv Y, Liu S, Guo W. The New Challenge of Obesity - Obesity-Associated Nephropathy. Diabetes Metab Syndr Obes 2024; 17:1957-1971. [PMID: 38737387 PMCID: PMC11086398 DOI: 10.2147/dmso.s433649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 02/28/2024] [Indexed: 05/14/2024] Open
Abstract
In recent years, obesity has become one of the major diseases that affect human health and consume human health resources, especially when it causes comorbidities such as hypertension, diabetes, cardiovascular disease and kidney disease. Many studies have demonstrated that obesity is associated with the development of chronic kidney disease and can exacerbate the progression of end-stage renal disease. This review described the mechanisms associated with the development of obesity-associated nephropathy and the current relevant therapeutic modalities, with the aim of finding new therapeutic targets for obesity-associated nephropathy. The mechanisms of obesity-induced renal injury include, in addition to the traditional alterations in renal hemodynamics, the involvement of various mechanisms such as macrophage infiltration in adipose tissue, alterations in adipokines (leptin and adiponectin), and ectopic deposition of lipids. At present, there is no "point-to-point" treatment for obesity-induced kidney injury. The renin-angiotensin-aldosterone system (RAAS) inhibitors, sodium-dependent glucose transporter 2 (SGLT-2) inhibitors and bariatric surgery described in this review can reduce urinary protein to varying degrees and delay the progression of kidney disease. In addition, recent studies on the therapeutic effects of intestinal flora on obesity may reduce the incidence of obesity-related kidney disease from the perspective of primary prevention. Both of these interventions have their own advantages and disadvantages, so the continuous search for the mechanism of obesity-induced related kidney disease will be extremely helpful for the future treatment of obesity-related kidney disease.
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Affiliation(s)
- Mengjin Hao
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin, 130021, People’s Republic of China
- Department of Endocrinology, Jining No. 1 People’s Hospital, Jining, Shandong, 272000, People’s Republic of China
| | - You Lv
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin, 130021, People’s Republic of China
| | - Siyuan Liu
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin, 130021, People’s Republic of China
| | - Weiying Guo
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin, 130021, People’s Republic of China
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Hu Y, Bao J, Gao Z, Ye L, Wang L. Sodium-Glucose Cotransporter Protein 2 Inhibitors: Novel Application for the Treatment of Obesity-Associated Hypertension. Diabetes Metab Syndr Obes 2024; 17:407-415. [PMID: 38292009 PMCID: PMC10826576 DOI: 10.2147/dmso.s446904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 01/13/2024] [Indexed: 02/01/2024] Open
Abstract
Obesity is becoming increasingly prevalent in China and worldwide and is closely related to the development of hypertension. The pathophysiology of obesity-associated hypertension is complex, including an overactive sympathetic nervous system (SNS), activation of the renin-angiotensin-aldosterone system (RAAS), insulin resistance, hyperleptinemia, renal dysfunction, inflammatory responses, and endothelial function, which complicates treatment. Sodium-glucose cotransporter protein 2 (SGLT-2) inhibitors, novel hypoglycemic agents, have been shown to reduce body weight and blood pressure and may serve as potential novel agents for the treatment of obesity-associated hypertension. This review discusses the beneficial mechanisms of SGLT-2 inhibitors for the treatment of obesity-associated hypertension. SGLT-2 inhibitors can inhibit SNS activity, reduce RAAS activation, ameliorate insulin resistance, reduce leptin secretion, improve renal function, and inhibit inflammatory responses. SGLT-2 inhibitors can, therefore, simultaneously target multiple mechanisms of obesity-associated hypertension and may serve as an effective treatment for obesity-associated hypertension.
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Affiliation(s)
- Yilan Hu
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, People’s Republic of China
- Heart Center, Department of Cardiovascular Medicine, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Hangzhou, People’s Republic of China
| | - Jiaqi Bao
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, People’s Republic of China
- Heart Center, Department of Cardiovascular Medicine, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Hangzhou, People’s Republic of China
| | - Zhicheng Gao
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, People’s Republic of China
- Heart Center, Department of Cardiovascular Medicine, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Hangzhou, People’s Republic of China
| | - Lifang Ye
- Heart Center, Department of Cardiovascular Medicine, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Hangzhou, People’s Republic of China
| | - Lihong Wang
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, People’s Republic of China
- Heart Center, Department of Cardiovascular Medicine, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Hangzhou, People’s Republic of China
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Parvanova A, Reseghetti E, Abbate M, Ruggenenti P. Mechanisms and treatment of obesity-related hypertension-Part 1: Mechanisms. Clin Kidney J 2024; 17:sfad282. [PMID: 38186879 PMCID: PMC10768772 DOI: 10.1093/ckj/sfad282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Indexed: 01/09/2024] Open
Abstract
The prevalence of obesity has tripled over the past five decades. Obesity, especially visceral obesity, is closely related to hypertension, increasing the risk of primary (essential) hypertension by 65%-75%. Hypertension is a major risk factor for cardiovascular disease, the leading cause of death worldwide, and its prevalence is rapidly increasing following the pandemic rise in obesity. Although the causal relationship between obesity and high blood pressure (BP) is well established, the detailed mechanisms for such association are still under research. For more than 30 years sympathetic nervous system (SNS) and kidney sodium reabsorption activation, secondary to insulin resistance and compensatory hyperinsulinemia, have been considered as primary mediators of elevated BP in obesity. However, experimental and clinical data show that severe insulin resistance and hyperinsulinemia can occur in the absence of elevated BP, challenging the causal relationship between insulin resistance and hyperinsulinemia as the key factor linking obesity to hypertension. The purpose of Part 1 of this review is to summarize the available data on recently emerging mechanisms believed to contribute to obesity-related hypertension through increased sodium reabsorption and volume expansion, such as: physical compression of the kidney by perirenal/intrarenal fat and overactivation of the systemic/renal SNS and the renin-angiotensin-aldosterone system. The role of hyperleptinemia, impaired chemoreceptor and baroreceptor reflexes, and increased perivascular fat is also discussed. Specifically targeting these mechanisms may pave the way for a new therapeutic intervention in the treatment of obesity-related hypertension in the context of 'precision medicine' principles, which will be discussed in Part 2.
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Affiliation(s)
- Aneliya Parvanova
- Department of Renal Medicine, Clinical Research Centre for Rare Diseases “Aldo e Cele Daccò”, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Elia Reseghetti
- Unit of Nephrology and Dialysis, Azienda Socio-Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy
| | - Manuela Abbate
- Research Group on Global Health, University of the Balearic Islands, Palma, Spain
- Research Group on Global Health and Lifestyle, Health Research Institutte of the Balearic Islands (IdISBa), Palma, Spain
| | - Piero Ruggenenti
- Department of Renal Medicine, Clinical Research Centre for Rare Diseases “Aldo e Cele Daccò”, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
- Unit of Nephrology and Dialysis, Azienda Socio-Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy
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Patel M, Braun J, Lambert G, Kameneva T, Keatch C, Lambert E. Central mechanisms in sympathetic nervous dysregulation in obesity. J Neurophysiol 2023; 130:1414-1424. [PMID: 37910522 DOI: 10.1152/jn.00254.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 10/16/2023] [Accepted: 10/26/2023] [Indexed: 11/03/2023] Open
Abstract
Cardiovascular and metabolic complications associated with excess adiposity are linked to chronic activation of the sympathetic nervous system, resulting in a high risk of mortality among obese individuals. Obesity-related positive energy balance underlies the progression of hypertension, end-organ damage, and insulin resistance, driven by increased sympathetic tone throughout the body. It is, therefore, important to understand the central network that drives and maintains sustained activation of the sympathetic nervous system in the obese state. Experimental and clinical studies have identified structural changes and altered dynamics in both grey and white matter regions in obesity. Aberrant activation in certain brain regions has been associated with altered reward circuitry and metabolic pathways including leptin and insulin signaling along with adiposity-driven systemic and central inflammation. The impact of these pathways on the brain via overactivity of the sympathetic nervous system has gained interest in the past decade. Primarily, the brainstem, hypothalamus, amygdala, hippocampus, and cortical structures including the insular, orbitofrontal, temporal, cingulate, and prefrontal cortices have been identified in this context. Although the central network involving these structures is much more intricate, this review highlights recent evidence identifying these regions in sympathetic overactivity in obesity.
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Affiliation(s)
- Mariya Patel
- School of Health Sciences, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - Joe Braun
- School of Health Sciences, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - Gavin Lambert
- School of Health Sciences, Swinburne University of Technology, Melbourne, Victoria, Australia
- Iverson Health Innovation Research Institute, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - Tatiana Kameneva
- Iverson Health Innovation Research Institute, Swinburne University of Technology, Melbourne, Victoria, Australia
- School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Melbourne, Victoria, Australia
- Department of Biomedical Engineering, The University of Melbourne, Melbourne, Victoria, Australia
| | - Charlotte Keatch
- School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - Elisabeth Lambert
- School of Health Sciences, Swinburne University of Technology, Melbourne, Victoria, Australia
- Iverson Health Innovation Research Institute, Swinburne University of Technology, Melbourne, Victoria, Australia
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7
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Yew YW, Mina T, Ng HK, Lam BCC, Riboli E, Lee ES, Lee J, Ngeow J, Elliott P, Thng STG, Chambers JC, Loh M. Investigating causal relationships between obesity and skin barrier function in a multi-ethnic Asian general population cohort. Int J Obes (Lond) 2023; 47:963-969. [PMID: 37479793 PMCID: PMC10511308 DOI: 10.1038/s41366-023-01343-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/23/2023] [Accepted: 07/05/2023] [Indexed: 07/23/2023]
Abstract
BACKGROUND Skin diseases impact significantly on the quality of life and psychology of patients. Obesity has been observed as a risk factor for skin diseases. Skin epidermal barrier dysfunctions are typical manifestations across several dermatological disturbances. OBJECTIVES We aim to establish the association between obesity and skin physiology measurements and investigate whether obesity may play a possible causal role on skin barrier dysfunction. METHODS We investigated the relationship of obesity with skin physiology measurements, namely transepidermal water loss (TEWL), skin surface moisture and skin pH in an Asian population cohort (n = 9990). To assess for a possible causal association between body mass index (BMI) and skin physiology measurements, we performed Mendelian Randomization (MR), along with subsequent additional analyses to assess the potential causal impact of known socioeconomic and comorbidities of obesity on TEWL. RESULTS Every 1 kg/m2 increase in BMI was associated with a 0.221% (95%CI: 0.144-0.298) increase in TEWL (P = 2.82E-08), a 0.336% (95%CI: 0.148-0.524) decrease in skin moisture (P = 4.66E-04) and a 0.184% (95%CI: 0.144-0.224) decrease in pH (P = 1.36E-19), adjusting for age, gender, and ethnicity. Relationships for both TEWL and pH with BMI remained strong (Beta 0.354; 95%CI: 0.189-0.520 and Beta -0.170; 95%CI: -0.253 to -0.087, respectively) even after adjusting for known confounders, with MR experiments further supporting BMI's possible causal relationship with TEWL. Based on additional MR performed, none of the socioeconomic and comorbidities of obesity investigated are likely to have possible causal relationships with TEWL. CONCLUSION We establish strong association of BMI with TEWL and skin pH, with MR results suggestive of a possible causal relationship of obesity with TEWL. It emphasizes the potential impact of obesity on skin barrier function and therefore opportunity for primary prevention.
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Affiliation(s)
- Yik Weng Yew
- National Skin Centre, Singapore, 308205, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Clinical Sciences Building, Singapore, 308232, Singapore
| | - Theresia Mina
- Lee Kong Chian School of Medicine, Nanyang Technological University, Clinical Sciences Building, Singapore, 308232, Singapore
| | - Hong Kiat Ng
- Lee Kong Chian School of Medicine, Nanyang Technological University, Clinical Sciences Building, Singapore, 308232, Singapore
| | - Benjamin Chih Chiang Lam
- Lee Kong Chian School of Medicine, Nanyang Technological University, Clinical Sciences Building, Singapore, 308232, Singapore
- Khoo Teck Puat Hospital, Integrated Care for Obesity & Diabetes, Singapore, 768828, Singapore
| | - Elio Riboli
- Lee Kong Chian School of Medicine, Nanyang Technological University, Clinical Sciences Building, Singapore, 308232, Singapore
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, St Mary's Campus, London, W2 1NY, United Kingdom
| | - Eng Sing Lee
- Lee Kong Chian School of Medicine, Nanyang Technological University, Clinical Sciences Building, Singapore, 308232, Singapore
- Clinical Research Unit, National Healthcare Group Polyclinic, Nexus@one-north, Singapore, 138543, Singapore
| | - Jimmy Lee
- Lee Kong Chian School of Medicine, Nanyang Technological University, Clinical Sciences Building, Singapore, 308232, Singapore
- Research Division, Institute of Mental Health, Singapore, 539747, Singapore
| | - Joanne Ngeow
- Lee Kong Chian School of Medicine, Nanyang Technological University, Clinical Sciences Building, Singapore, 308232, Singapore
- Division of Medical Oncology, National Cancer Centre, Singapore, 169610, Singapore
| | - Paul Elliott
- Lee Kong Chian School of Medicine, Nanyang Technological University, Clinical Sciences Building, Singapore, 308232, Singapore
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, St Mary's Campus, London, W2 1NY, United Kingdom
| | | | - John C Chambers
- Lee Kong Chian School of Medicine, Nanyang Technological University, Clinical Sciences Building, Singapore, 308232, Singapore
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, St Mary's Campus, London, W2 1NY, United Kingdom
| | - Marie Loh
- National Skin Centre, Singapore, 308205, Singapore.
- Lee Kong Chian School of Medicine, Nanyang Technological University, Clinical Sciences Building, Singapore, 308232, Singapore.
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, St Mary's Campus, London, W2 1NY, United Kingdom.
- Genome Institute of Singapore (GIS), Agency for Science, Technology and Research (A*STAR), Singapore, 138672, Singapore.
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Jung MH, Ihm SH. Obesity-related hypertension and chronic kidney disease: from evaluation to management. Kidney Res Clin Pract 2023; 42:431-444. [PMID: 37551125 PMCID: PMC10407638 DOI: 10.23876/j.krcp.23.072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/14/2023] [Accepted: 06/15/2023] [Indexed: 08/09/2023] Open
Abstract
With the recent obesity pandemic, obesity-related hypertension and its complications (e.g., heart failure, coronary disease, and chronic kidney disease [CKD]) are gaining attention in clinical and research fields. Obesity-related hypertension frequently precedes the onset of CKD and aggravates its progression. In this review, we discuss the role of visceral fat in the pathophysiology of obesity-related hypertension and the potential therapeutic strategies for its prevention and management. Various factors, including the sympathetic nervous system, renin-angiotensin-aldosterone system, and inflammatory pathways, are intricately involved in the pathogenesis of obesity-related hypertension. These factors individually and jointly contribute to the development of hypertension (usually sodium-sensitive or resistant hypertension) and, ultimately, to the progression of CKD. From a clinical standpoint, a decline in renal function in advanced CKD further makes blood pressure control challenging since only a few options are available for blood pressure-lowering medications. Proactive lifestyle modification, pharmacological treatment for obesity, and bariatric surgery can be considered for obesity control and management. Furthermore, intensive blood pressure control is required to prevent and halt the development and progression of CKD.
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Grants
- 2011E3300300, 2012E3301100, 2013E3301600, 2013E3301601, 2013E3301602, 2016E3300200, 2016E330 0201, 2016E3300202,2019E320100, 2019E320101, 2019 E320102, 2022-11-007 Korea Disease Control and Prevention Agency
- NRF-2019R1A2C2086276 National Research Foundation of Korea
- BCRI22042, BCRI22079 Chonnam National University Hospital Biomedical Research Institute
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Affiliation(s)
- Mi-Hyang Jung
- Division of Cardiology, Department of Internal Medicine, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Catholic Research Institute for Intractable Cardiovascular Disease, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Sang-Hyun Ihm
- Catholic Research Institute for Intractable Cardiovascular Disease, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Division of Cardiology, Department of Internal Medicine, Bucheon St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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Chomanskis Ž, Jonkus V, Danielius T, Paulauskas T, Orvydaitė M, Melaika K, Rukšėnas O, Hendrixson V, Ročka S. Hypotensive Effect of Electric Stimulation of Caudal Ventrolateral Medulla in Freely Moving Rats. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1046. [PMID: 37374250 DOI: 10.3390/medicina59061046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 06/29/2023]
Abstract
Background and Objectives: An altered sympathetic function is established in primary arterial hypertension (PAH) development. Therefore, PAH could be targeted by applying an electric current to the medulla where reflex centers for blood pressure control reside. This study aims to evaluate the electric caudal ventrolateral medulla (CVLM) stimulation effect on blood pressure and animal survivability in a freely moving rat model. Materials and Methods: A total of 20 Wistar rats aged 12-16 weeks were randomly assigned to either: the experimental group (n = 10; electrode tip implanted in CVLM region) or the control group (n = 10; tip implanted 4 mm above the CVLM in the cerebellum). After a period of recovery (4 days), an experimental phase ensued, divided into an "OFF stimulation" period (5-7 days post-surgery) and an "ON stimulation" period (8-14 days post-surgery). Results: Three animals (15%, one in the control, two in the experimental group) dropped out due to postoperative complications. Arterial pressure in the experimental group rats during the "OFF stimulation" period decreased by 8.23 mm Hg (p = 0.001) and heart rate by 26.93 beats/min (p = 0.008). Conclusions: From a physiological perspective, CVLM could be an effective deep brain stimulation (DBS) target for drug-resistant hypertension: able to influence the baroreflex arc directly, having no known direct integrative or neuroendocrine function. Targeting the baroreflex regulatory center, but not its sensory or effector parts, could lead to a more predictable effect and stability of the control system. Although targeting neural centers in the medullary region is considered dangerous and prone to complications, it could open a new vista for deep brain stimulation therapy. A possible change in electrode design would be required to apply CVLM DBS in clinical trials in the future.
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Affiliation(s)
- Žilvinas Chomanskis
- Clinic of Neurology and Neurosurgery, Faculty of Medicine, Vilnius University, LT-01513 Vilnius, Lithuania
| | - Vytautas Jonkus
- Faculty of Physics, Vilnius University, LT-01513 Vilnius, Lithuania
| | - Tadas Danielius
- Institute of Applied Mathematics, Faculty of Mathematics and Informatics, Vilnius University, LT-01513 Vilnius, Lithuania
| | - Tomas Paulauskas
- Department of Neurobiology and Biophysics, Institute of Biosciences, Life Sciences Center, Vilnius University, LT-01513 Vilnius, Lithuania
| | - Monika Orvydaitė
- Faculty of Medicine, Vilnius University, LT-01513 Vilnius, Lithuania
| | | | - Osvaldas Rukšėnas
- Department of Neurobiology and Biophysics, Institute of Biosciences, Life Sciences Center, Vilnius University, LT-01513 Vilnius, Lithuania
| | - Vaiva Hendrixson
- Department of Physiology, Biochemistry, Microbiology and Laboratory Medicine, Institute of Biomedical Sciences, Faculty of Medicine, Vilnius University, LT-01513 Vilnius, Lithuania
| | - Saulius Ročka
- Clinic of Neurology and Neurosurgery, Faculty of Medicine, Vilnius University, LT-01513 Vilnius, Lithuania
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10
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Strain MM, Espinoza L, Fedorchak S, Littlejohn EL, Andrade MA, Toney GM, Boychuk CR. Early central cardiovagal dysfunction after high fat diet in a murine model. Sci Rep 2023; 13:6550. [PMID: 37085567 PMCID: PMC10121716 DOI: 10.1038/s41598-023-32492-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 03/28/2023] [Indexed: 04/23/2023] Open
Abstract
High fat diet (HFD) promotes cardiovascular disease and blunted cardiac vagal regulation. Temporal onset of loss of cardiac vagal control and its underlying mechanism are presently unclear. We tested our hypothesis that reduced central vagal regulation occurs early after HFD and contributes to poor cardiac regulation using cardiovascular testing paired with pharmacology in mice, molecular biology, and a novel bi-transgenic mouse line. Results show HFD, compared to normal fat diet (NFD), significantly blunted cardio/pulmonary chemoreflex bradycardic responses after 15 days, extending as far as tested (> 30 days). HFD produced resting tachycardia by day 3, reflected significant loss of parasympathetic tone. No differences in bradycardic responses to graded electrical stimulation of the distal cut end of the cervical vagus indicated diet-induced differences in vagal activity were centrally mediated. In nucleus ambiguus (NA), surface expression of δ-subunit containing type A gamma-aminobutyric acid receptors (GABAA(δ)R) increased at day 15 of HFD. Novel mice lacking δ-subunit expression in vagal motor neurons (ChAT-δnull) failed to exhibit blunted reflex bradycardia or resting tachycardia after two weeks of HFD. Thus, reduced parasympathetic output contributes to early HFD-induced HR dysregulation, likely through increased GABAA(δ)Rs. Results underscore need for research on mechanisms of early onset increases in GABAA(δ)R expression and parasympathetic dysfunction after HFD.
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Affiliation(s)
- Misty M Strain
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Liliana Espinoza
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Stephanie Fedorchak
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Erica L Littlejohn
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Mary Ann Andrade
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Glenn M Toney
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Carie R Boychuk
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA.
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11
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Shen A, Li R, Li Y, Guo J, Wang J, Sui X. A system of real-time neural recording and stimulation and its potential application in blood pressure modulation. FRONTIERS IN MEDICAL TECHNOLOGY 2022; 4:941686. [PMID: 36035774 PMCID: PMC9399767 DOI: 10.3389/fmedt.2022.941686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 07/12/2022] [Indexed: 11/13/2022] Open
Abstract
Hypertension is one of the most prevalent chronic diseases that affects more than 20% of the adult population worldwide, but fortunately, most of their blood pressure can be effectively controlled via drug treatment. However, there still remains 5–30% of patients clinically who do not respond well to conventional medication, while the non-drug treatments currently existing are struggling with major drawbacks like irreversible nerve damage, huge side effects, and even non-effectiveness. In this study, based on the physiological regulation mechanism of blood pressure and state-of-the-art neuromodulation technique, we worked along with the vagus nerve stimulation scheme, developed, and explored whether and how a real-time neural recording and stimulation system could provide an insight into self-adaptive modulation in the blood pressure, in the hope to crack a crevice in the closed-loop treatment for resistant hypertension. Unlike traditional neuromodulation devices, additional signal recording and real-time wireless transmission functions are added to the same device to realize the features of a dynamic monitor and modulator. The system is tested both in vitro and in vivo, showing decent electrical performance of 8 kHz sampling rate and flexible stimulation outputs which sufficiently covers our needs in manipulating neural activities of interest. A relatively stable drop in the blood pressure resulting from stimulation was observed and specific patterns in the vagus nerve signals relating to blood pressure could also be primarily identified. This laid a solid foundation for further studies on the final realization of closed-loop automatic adjustment for resistive hypertension treatment.
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Affiliation(s)
- Anruo Shen
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
- School of Medicine, Tsinghua University, Beijing, China
| | - Runhuan Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yiran Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Jinyao Guo
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Jiguang Wang
- Shanghai Institute of Hypertension, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Jiguang Wang
| | - Xiaohong Sui
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
- *Correspondence: Xiaohong Sui
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12
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Nazari S, Moosavi SMS. Temporal patterns of alterations in obesity index, lipid profile, renal function and blood pressure during the development of hypertension in male, but not female, rats fed a moderately high-fat diet. Arch Physiol Biochem 2022; 128:897-909. [PMID: 32195603 DOI: 10.1080/13813455.2020.1739713] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
CONTEXT Male Sprague-Dawley rats consuming a moderately high-fat (MHF)-diet diverge into obesity-prone (OP) with hypertension and obesity-resistant. OBJECTIVES To study the temporal inter-relationships between body-weight, obesity-index, plasma lipid-profile, renal functional parameters and systolic-pressure alterations during 10-weeks feeding MHF or normal diet to male and female rats. METHODS Body-weight, obesity-index and systolic-pressure were measured weekly, while metabolic-cage and blood-sampling protocols were performed every other week. After 10-weeks, renal excretory responses to acute salt-loading and renal autoregulation were examined. RESULTS The male-OP group had progressively increased body-weight, plasma-triglyceride and systolic-pressure from Weeks 2, 4 and 5, respectively, lower renal sodium-excretion at weeks 4-8 and finally, delayed excretory response to salt-loading and rightward and downward shifts in renal autoregulatory curves compared to all other groups. CONCLUSION Feeding the MHF-diet in male-OP rats led to a greater weight-gain and adiposity followed by the development of atherogenic-hyperlipidaemia and persistently impaired pressure-natriuresis to induce hypertension.
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Affiliation(s)
- Somayeh Nazari
- Department of Physiology, The Medical School, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Seyed Mostafa Shid Moosavi
- Department of Physiology, The Medical School, Shiraz University of Medical Sciences, Shiraz, Iran
- Shiraz Nephro-Urology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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13
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Ferreira ARO, Ribeiro MVG, Peres MNC, Piovan S, Gonçalves GD, Saavedra LPJ, Martins JNDL, Junior MDF, Cavalcante KVN, Lopes GKG, Carneiro M, Almeida DL, Gomes RM, Comar JF, Armitage JA, Mathias PCDF, Palma-Rigo K. Protein Restriction in the Peri-Pubertal Period Induces Autonomic Dysfunction and Cardiac and Vascular Structural Changes in Adult Rats. Front Physiol 2022; 13:840179. [PMID: 35574445 PMCID: PMC9095958 DOI: 10.3389/fphys.2022.840179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 03/22/2022] [Indexed: 11/30/2022] Open
Abstract
Perturbations to nutrition during critical periods are associated with changes in embryonic, fetal or postnatal developmental patterns that may render the offspring more likely to develop cardiovascular disease in later life. The aim of this study was to evaluate whether autonomic nervous system imbalance underpins in the long-term hypertension induced by dietary protein restriction during peri-pubertal period. Male Wistar rats were assigned to groups fed with a low protein (4% protein, LP) or control diet (20.5% protein; NP) during peri-puberty, from post-natal day (PN) 30 until PN60, and then all were returned to a normal protein diet until evaluation of cardiovascular and autonomic function at PN120. LP rats showed long-term increased mean arterial pressure (p = 0.002) and sympathetic arousal; increased power of the low frequency (LF) band of the arterial pressure spectral (p = 0.080) compared with NP animals. The depressor response to the ganglion blocker hexamethonium was increased in LP compared with control animals (p = 0.006). Pulse interval variability showed an increase in the LF band and LF/HF ratio (p = 0.062 and p = 0.048) in LP animals. The cardiac response to atenolol and/or methylatropine and the baroreflex sensitivity were similar between groups. LP animals showed ventricular hypertrophy (p = 0.044) and increased interstitial fibrosis (p = 0.028) compared with controls. Reduced protein carbonyls (PC) (p = 0.030) and catalase activity (p = 0.001) were observed in hearts from LP animals compared with control. In the brainstem, the levels of PC (p = 0.002) and the activity of superoxide dismutase and catalase (p = 0.044 and p = 0.012) were reduced in LP animals, while the levels of GSH and total glutathione were higher (p = 0.039 and p = 0.038) compared with NP animals. Protein restriction during peri-pubertal period leads to hypertension later in life accompanied by sustained sympathetic arousal, which may be associated with a disorganization of brain and cardiac redox state and structural cardiac alteration.
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Affiliation(s)
- Anna Rebeka Oliveira Ferreira
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Maiara Vanusa Guedes Ribeiro
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Maria Natalia Chimirri Peres
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Silvano Piovan
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Géssica Dutra Gonçalves
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Lucas Paulo Jacinto Saavedra
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Juliana Nunes de Lima Martins
- Laboratory of Liver Metabolism and Radioisotopes, Department of Biochemistry, State University of Maringa, Maringa, Brazil
| | - Marcos Divino Ferreira Junior
- Laboratory of Endocrine Physiology and Metabolism, Department of Physiological Sciences, Federal University of Goias, Goiania, Brazil
| | - Keilah Valeria Naves Cavalcante
- Laboratory of Endocrine Physiology and Metabolism, Department of Physiological Sciences, Federal University of Goias, Goiania, Brazil
| | - Gabriel kian Guimarães Lopes
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Mariane Carneiro
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Douglas Lopes Almeida
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Rodrigo Mello Gomes
- Laboratory of Endocrine Physiology and Metabolism, Department of Physiological Sciences, Federal University of Goias, Goiania, Brazil
| | - Jurandir Fernando Comar
- Laboratory of Liver Metabolism and Radioisotopes, Department of Biochemistry, State University of Maringa, Maringa, Brazil
| | | | - Paulo Cezar de Freitas Mathias
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Kesia Palma-Rigo
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
- Adventist College of Parana, Ivatuba, Brazil
- *Correspondence: Kesia Palma-Rigo,
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14
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Nogueira TR, Marreiros CS, Almendra Freitas BDJESD. Chronic Kidney Disease, Metabolic Syndrome and Cardiovascular Risk: Insights and Associated Mechanistic Pathways. CURRENT NUTRITION & FOOD SCIENCE 2022. [DOI: 10.2174/1573401318666220203164619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract:
This study is a narrative review that aims to address the conceptual, characteristic, pathophysiological, and mechanistic aspects that define the profile of metabolic syndrome and chronic kidney disease. The objective was to investigate current knowledge and elucidate, through discussions on the topic, the main interrelated paths. This review was carried out unsystematically, from March to May 2020, by means of a survey of the literature indexed in the PubMed, Web of Science, and Scopus (Elsevier®) databases. The scientific materials collected showed that the cross-talk between the diseases in question is mainly based on the conditions of resistance to insulin action, endothelial dysfunction, activation pathways of the Renin-Angiotensin-Aldosterone system and adipokine imbalance, also emphasizing the influence of atherosclerotic events in kidney damage. Furthermore, it was reinforced the fact that inflammatory processes play an important role in the worsening and evolution of the clinical condition of patients, especially when they have underlying pathologies chronically treated for subclinical inflammation. It is expected that a greater number of original researches will propose to investigate other possible interactions, with a view to standardized treatment of these diseases or nutritional management.
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Affiliation(s)
- Thaís Rodrigues Nogueira
- Master in Food and Nutrition, Department of Nutrition, Federal University of Piauí, UFPI, Piauí State, Teresina, Brazil
| | - Camila Santos Marreiros
- Master in Food and Nutrition, Department of Nutrition, Federal University of Piauí, UFPI, Piauí State, Teresina, Brazil
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15
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Gemici A, Sinen O, Bülbül M. Sexual dimorphism in rats exposed to maternal high fat diet: alterations in medullary sympathetic network. Metab Brain Dis 2021; 36:1305-1314. [PMID: 33914222 DOI: 10.1007/s11011-021-00736-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 04/08/2021] [Indexed: 10/21/2022]
Abstract
Exposure to high fat diet during perinatal period (PHFD) leads to neuroplastic changes in autonomic circuits, however, the role of gender has been incompletely understood. This study aims to investigate (i) short, and (ii) long-term effects of PHFD on autonomic outflow, and (iii) sexual dimorphic variations emerge at adulthood. Male and female rats were fed a control diet (13.5 % kcal from fat) or PHFD (60 % kcal from fat) from embryonic day-14 to postnatal day-21. To assess changes in autonomic outflow, heart rate variability (HRV) was analyzed at 10- and 20-week-old ages. Expressions of tyrosine hydroxylase (TH), metabotropic glutamate2/3 receptor (mGlu2/3R), N-methyl-D-aspartate1 receptor (NMDA1R), and gamma aminobutyric acidA receptor (GABAAR) were evaluated by immunohistochemistry. PHFD did not affect the body weight of 4-, 10-or 20-week-old male or female offsprings. PHFD significantly increased the sympathetic marker low frequency (LF) component, and sympatho-vagal balance (LF:HF) only in 10-week-old PHFD males. Compared with control, the propranolol-induced (4 mg·kg- 1, ip) decline in LF was observed more prominently in PHFD rats, however, these changes were found to be restored at the age of 20 weeks. In caudal ventrolateral medulla and nucleus tractus solitarius, expression of mGlu2/3R was downregulated in PHFD males, whereas no change was detected in NMDA1R. The number of GABAAR-expressing TH-immunoreactive cells was decreased in rostral ventrolateral medulla of PHFD males. The findings of this study suggest that exposure to maternal high-fat diet could lead to autonomic imbalance with increased sympathetic tone in the early adulthood of male offspring rats without developing obesity.
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Affiliation(s)
- Ayşegül Gemici
- Department of Physiology, Faculty of Medicine, Akdeniz University, 07070, Antalya, Turkey
| | - Osman Sinen
- Department of Physiology, Faculty of Medicine, Akdeniz University, 07070, Antalya, Turkey
| | - Mehmet Bülbül
- Department of Physiology, Faculty of Medicine, Akdeniz University, 07070, Antalya, Turkey.
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16
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Lim K, Burke SL, Marques FZ, Jackson KL, Gueguen C, Sata Y, Armitage JA, Head GA. Leptin and Melanocortin Signaling Mediates Hypertension in Offspring From Female Rabbits Fed a High-Fat Diet During Gestation and Lactation. Front Physiol 2021; 12:693157. [PMID: 34248679 PMCID: PMC8264761 DOI: 10.3389/fphys.2021.693157] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 05/24/2021] [Indexed: 01/02/2023] Open
Abstract
Maternal high-fat diet in rabbits leads to hypertension and elevated renal sympathetic nerve activity (RSNA) in adult offspring but whether this is due to adiposity or maternal programming is unclear. We gave intracerebroventricular (ICV) and ventromedial hypothalamus (VMH) administration of leptin-receptor antagonist, α-melanocyte-stimulating hormone (αMSH), melanocortin-receptor antagonist (SHU9119), or insulin-receptor (InsR) antagonist to conscious adult offspring from mothers fed a high-fat diet (mHFD), control diet (mCD), or mCD offspring fed HFD for 10d (mCD10d, to deposit equivalent fat but not during development). mHFD and mCD10d rabbits had higher mean arterial pressure (MAP, +6.4 mmHg, +12.1 mmHg, p < 0.001) and RSNA (+2.3 nu, +3.2 nu, p < 0.01) than mCD, but all had similar plasma leptin. VMH leptin-receptor antagonist reduced MAP (−8.0 ± 3.0 mmHg, p < 0.001) in mCD10d but not in mHFD or mCD group. Intracerebroventricular leptin-receptor antagonist reduced MAP only in mHFD rabbits (p < 0.05). Intracerebroventricular SHU9119 reduced MAP and RSNA in mHFD but only reduced MAP in the mCD10d group. VMH αMSH increased RSNA (+85%, p < 0.001) in mHFD rabbits but ICV αMSH increased RSNA in both mHFD and mCD10d rabbits (+45%, +51%, respectively, p < 0.001). The InsR antagonist had no effect by either route on MAP or RSNA. Hypothalamic leptin receptor and brain-derived neurotrophic factor (BDNF) mRNA were greater in mHFD compared with mCD rabbits and mCD10d rabbits. In conclusion, the higher MAP in mHFD and mCD10d offspring was likely due to greater central leptin signaling at distinct sites within the hypothalamus while enhanced melanocortin contribution was common to both groups suggesting that residual body fat was mainly responsible. However, the effects of SHU9119 and αMSH on RSNA pathways only in mHFD suggest a maternal HFD may program sympatho-excitatory capacity in these offspring and that this may involve increased leptin receptor and BDNF expression.
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Affiliation(s)
- Kyungjoon Lim
- Neuropharmacology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Department of Physiology, Anatomy and Microbiology, La Trobe University, Bundoora, VIC, Australia
| | - Sandra L Burke
- Neuropharmacology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Francine Z Marques
- Heart Failure Research Group, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Hypertension Research Laboratory, School of Biological Sciences, Faculty of Science, Monash University, Clayton, VIC, Australia
| | - Kristy L Jackson
- Neuropharmacology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Cindy Gueguen
- Neuropharmacology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Yusuke Sata
- Neuropharmacology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Human Neurotransmitters Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Faculty of Medicine, Nursing and Health Sciences, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Cardiology, Alfred Hospital, Melbourne, VIC, Australia
| | - James A Armitage
- School of Medicine (Optometry), and IMPACT Institute for Innovation in Physical and Mental Health and Clinical Translation, Faculty of Health, Deakin University, Waurn Ponds, VIC, Australia
| | - Geoffrey A Head
- Neuropharmacology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Department of Pharmacology, Monash University, Clayton, VIC, Australia
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17
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Xu J, Qu P, Du X, Xiang Q, Guo L, Zhu L, Tan Y, Fu Y, Wen T, Liu L. Change in Postprandial Level of Remnant Cholesterol After a Daily Breakfast in Chinese Patients With Hypertension. Front Cardiovasc Med 2021; 8:685385. [PMID: 34212015 PMCID: PMC8239280 DOI: 10.3389/fcvm.2021.685385] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 05/11/2021] [Indexed: 12/28/2022] Open
Abstract
Background: Hypertension (HBP) is usually accompanied by hypertriglyceridemia that represents the increased triglyceride-rich lipoproteins and cholesterol content in remnant lipoproteins [i.e., remnant cholesterol (RC)]. According to the European Atherosclerosis Society (EAS), high RC (HRC) is defined as fasting RC ≥0.8 mmol/L and/or postprandial RC ≥0.9 mmol/L. However, little is known about postprandial change in RC level after a daily meal in Chinese patients with HBP. Methods: One hundred thirty-five subjects, including 90 hypertensive patients (HBP group) and 45 non-HBP controls (CON group), were recruited in this study. Serum levels of blood lipids, including calculated RC, were explored at 0, 2, and 4 h after a daily breakfast. Receiver operating characteristic (ROC) curve analysis was used to determine the cutoff point of postprandial HRC. Results: Fasting TG and RC levels were significantly higher in the HBP group (P < 0.05), both of which increased significantly after a daily meal in the two groups (P < 0.05). Moreover, postprandial RC level was significantly higher in the HBP group (P < 0.05). ROC curve analysis showed that the optimal cutoff point for RC after a daily meal to predict HRC corresponding to fasting RC of 0.8 mmol/L was 0.91 mmol/L, which was very close to that recommended by the EAS, i.e., 0.9 mmol/L. Fasting HRC was found in 31.1% of hypertensive patients but not in the controls. According to the postprandial cutoff point, postprandial HRC was found in approximately half of hypertensive patients and ~1-third of the controls. Conclusion: Postprandial RC level increased significantly after a daily meal, and hypertensive patients had higher percentage of HRC at both fasting and postprandial states. More importantly, the detection of postprandial lipids could be helpful to find HRC.
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Affiliation(s)
- Jin Xu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, China.,Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, China.,Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, China.,Cardiovascular Disease Research Center of Hunan Province, Changsha, China
| | - Peiliu Qu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, China.,Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, China.,Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, China.,Cardiovascular Disease Research Center of Hunan Province, Changsha, China
| | - Xiao Du
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, China.,Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, China.,Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, China.,Cardiovascular Disease Research Center of Hunan Province, Changsha, China
| | - Qunyan Xiang
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, China.,Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, China.,Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, China.,Cardiovascular Disease Research Center of Hunan Province, Changsha, China
| | - Liling Guo
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, China.,Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, China.,Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, China.,Cardiovascular Disease Research Center of Hunan Province, Changsha, China
| | - Liyuan Zhu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, China.,Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, China.,Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, China.,Cardiovascular Disease Research Center of Hunan Province, Changsha, China
| | - Yangrong Tan
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, China.,Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, China.,Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, China.,Cardiovascular Disease Research Center of Hunan Province, Changsha, China
| | - Yan Fu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, China.,Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, China.,Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, China.,Cardiovascular Disease Research Center of Hunan Province, Changsha, China
| | - Tie Wen
- Department of Emergency Medicine, Second Xiangya Hospital, Central South University, Changsha, China.,Emergency Medicine and Difficult Diseases Institute, Second Xiangya Hospital, Central South University, Changsha, China
| | - Ling Liu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, China.,Research Institute of Blood Lipid and Atherosclerosis, Central South University, Changsha, China.,Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Changsha, China.,Cardiovascular Disease Research Center of Hunan Province, Changsha, China
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18
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Osborn JW, Tyshynsky R, Vulchanova L. Function of Renal Nerves in Kidney Physiology and Pathophysiology. Annu Rev Physiol 2021; 83:429-450. [PMID: 33566672 DOI: 10.1146/annurev-physiol-031620-091656] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Renal sympathetic (efferent) nerves play an important role in the regulation of renal function, including glomerular filtration, sodium reabsorption, and renin release. The kidney is also innervated by sensory (afferent) nerves that relay information to the brain to modulate sympathetic outflow. Hypertension and other cardiometabolic diseases are linked to overactivity of renal sympathetic and sensory nerves, but our mechanistic understanding of these relationships is limited. Clinical trials of catheter-based renal nerve ablation to treat hypertension have yielded promising results. Therefore, a greater understanding of how renal nerves control the kidney under physiological and pathophysiological conditions is needed. In this review, we provide an overview of the current knowledge of the anatomy of efferent and afferent renal nerves and their functions in normal and pathophysiological conditions. We also suggest further avenues of research for development of novel therapies targeting the renal nerves.
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Affiliation(s)
- John W Osborn
- Department of Surgery, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA;
| | - Roman Tyshynsky
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Lucy Vulchanova
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, USA
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19
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Hall JE, Mouton AJ, da Silva AA, Omoto ACM, Wang Z, Li X, do Carmo JM. Obesity, kidney dysfunction, and inflammation: interactions in hypertension. Cardiovasc Res 2020; 117:1859-1876. [PMID: 33258945 DOI: 10.1093/cvr/cvaa336] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/01/2020] [Accepted: 11/17/2020] [Indexed: 12/20/2022] Open
Abstract
Obesity contributes 65-75% of the risk for human primary (essential) hypertension (HT) which is a major driver of cardiovascular and kidney diseases. Kidney dysfunction, associated with increased renal sodium reabsorption and compensatory glomerular hyperfiltration, plays a key role in initiating obesity-HT and target organ injury. Mediators of kidney dysfunction and increased blood pressure include (i) elevated renal sympathetic nerve activity (RSNA); (ii) increased antinatriuretic hormones such as angiotensin II and aldosterone; (iii) relative deficiency of natriuretic hormones; (iv) renal compression by fat in and around the kidneys; and (v) activation of innate and adaptive immune cells that invade tissues throughout the body, producing inflammatory cytokines/chemokines that contribute to vascular and target organ injury, and exacerbate HT. These neurohormonal, renal, and inflammatory mechanisms of obesity-HT are interdependent. For example, excess adiposity increases the adipocyte-derived cytokine leptin which increases RSNA by stimulating the central nervous system proopiomelanocortin-melanocortin 4 receptor pathway. Excess visceral, perirenal and renal sinus fat compress the kidneys which, along with increased RSNA, contribute to renin-angiotensin-aldosterone system activation, although obesity may also activate mineralocorticoid receptors independent of aldosterone. Prolonged obesity, HT, metabolic abnormalities, and inflammation cause progressive renal injury, making HT more resistant to therapy and often requiring multiple antihypertensive drugs and concurrent treatment of dyslipidaemia, insulin resistance, diabetes, and inflammation. More effective anti-obesity drugs are needed to prevent the cascade of cardiorenal, metabolic, and immune disorders that threaten to overwhelm health care systems as obesity prevalence continues to increase.
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Affiliation(s)
- John E Hall
- Department of Physiology & Biophysics, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA.,Mississippi Center for Clinical and Translational Research, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA
| | - Alan J Mouton
- Department of Physiology & Biophysics, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA
| | - Alexandre A da Silva
- Department of Physiology & Biophysics, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA
| | - Ana C M Omoto
- Department of Physiology & Biophysics, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA
| | - Zhen Wang
- Department of Physiology & Biophysics, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA
| | - Xuan Li
- Department of Physiology & Biophysics, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA
| | - Jussara M do Carmo
- Department of Physiology & Biophysics, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 30216-4505, USA
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20
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Hirooka Y. Sympathetic Activation in Hypertension: Importance of the Central Nervous System. Am J Hypertens 2020; 33:914-926. [PMID: 32374869 DOI: 10.1093/ajh/hpaa074] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 04/18/2020] [Accepted: 05/01/2020] [Indexed: 12/20/2022] Open
Abstract
The sympathetic nervous system plays a critical role in the pathogenesis of hypertension. The central nervous system (CNS) organizes the sympathetic outflow and various inputs from the periphery. The brain renin-angiotensin system has been studied in various regions involved in controlling sympathetic outflow. Recent progress in cardiovascular research, particularly in vascular biology and neuroscience, as well as in traditional physiological approaches, has advanced the field of the neural control of hypertension in which the CNS plays a vital role. Cardiovascular research relating to hypertension has focused on the roles of nitric oxide, oxidative stress, inflammation, and immunity, and the network among various organs, including the heart, kidney, spleen, gut, and vasculature. The CNS mechanisms are similarly networked with these factors and are widely studied in neuroscience. In this review, I describe the development of the conceptual flow of this network in the field of hypertension on the basis of several important original research articles and discuss potential future breakthroughs leading to clinical precision medicine.
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Affiliation(s)
- Yoshitaka Hirooka
- Department of Medical Technology and Sciences, School of Health Sciences at Fukuoka, International University of Health and Welfare, Okawa City, Fukuoka, Japan
- Department of Cardiovascular Medicine, Hypertension and Heart Failure Center, Takagi Hospital, Okawa City, Fukuoka, Japan
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21
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Badoer E. The Carotid Body a Common Denominator for Cardiovascular and Metabolic Dysfunction? Front Physiol 2020; 11:1069. [PMID: 32982794 PMCID: PMC7478291 DOI: 10.3389/fphys.2020.01069] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 08/04/2020] [Indexed: 11/28/2022] Open
Abstract
The carotid body is a highly vascularized organ designed to monitor oxygen levels. Reducing oxygen levels in blood results in increased activity of the carotid body cells and reflex increases in sympathetic nerve activity. A key contributor to elevated sympathetic nerve activity in neurogenic forms of hypertension is enhanced peripheral chemoreceptor activity. Hypertension commonly occurs in metabolic disorders, like obesity. Such metabolic diseases are serious global health problems. Yet, the mechanisms contributing to increased sympathetic nerve activity and hypertension in obesity are not fully understood and a better understanding is urgently required. In this review, we examine the literature that suggests that overactivity of the carotid body may also contribute to metabolic disturbances. The purine ATP is an important chemical mediator influencing the activity of the carotid body and the role of purines in the overactivity of the carotid body is explored. We will conclude with the suggestion that tonic overactivity of the carotid body may be a common denominator that contributes to the hypertension and metabolic dysfunction seen in conditions in which metabolic disease exists such as obesity or insulin resistance induced by high caloric intake. Therapeutic treatment targeting the carotid bodies may be a viable treatment since translation to the clinic could be more easily performed than expected via repurposing antagonists of purinergic receptors currently in clinical practice, and the use of other minimally invasive techniques that reduce the overactivity of the carotid bodies which may be developed for such clinical use.
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Affiliation(s)
- Emilio Badoer
- School of Health and Biomedical Sciences, Royal Melbourne Institute of Technology (RMIT) University, Melbourne, VIC, Australia
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22
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Xue B, Zhang Y, Johnson AK. Interactions of the Brain Renin-Angiotensin-System (RAS) and Inflammation in the Sensitization of Hypertension. Front Neurosci 2020; 14:650. [PMID: 32760236 PMCID: PMC7373760 DOI: 10.3389/fnins.2020.00650] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 05/26/2020] [Indexed: 01/07/2023] Open
Abstract
Mounting evidence indicates that the renin-angiotensin (RAS) and immune systems interact with one another in the central nervous system (CNS) and that they are importantly involved in the pathogenesis of hypertension. Components comprising the classic RAS were first identified in the periphery, and subsequently, similar factors were found to be generated de novo in many different organs including the brain. There is humoral-neural coupling between the systemic and brain RASs, which is important for controlling sympathetic tone and the release of endocrine factors that collectively determine blood pressure (BP). Similar to the interactions between the systemic and brain RASs is the communication between the peripheral and brain immune systems. Systemic inflammation activates the brain’s immune response. Importantly, the RAS and inflammatory factors act synergistically in brain regions involved in the regulation of BP. This review presents evidence of how such interactions between the brain RAS and central immune mechanisms contribute to the pathogenesis of hypertension. Emphasis focuses on the role of these interactions to induce neuroplastic changes in a central neural network resulting in hypertensive response sensitization (HTRS). Neuroplasticity and HTRS can be induced by challenges (stressors) presented earlier in life such as a low-dose of angiotensin II or high fat diet (HFD) feeding in adults. Similarly, the offspring of mothers with gestational hypertension or of mothers ingesting a HFD during pregnancy are reprogrammed and manifest HTRS when exposed to new stressors as adults. Consideration of the actions and interactions of the brain RAS and inflammatory mediators in the context of the induction and expression of HTRS will provide insights into the etiology of high BP that may lead to new strategies for the prevention and treatment of hypertension.
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Affiliation(s)
- Baojian Xue
- Department of Psychological and Brain Sciences, The University of Iowa, Iowa City, IA, United States
| | - Yuping Zhang
- Department of Pathophysiology, Hebei North University, Zhangjiakou, China
| | - Alan Kim Johnson
- Department of Psychological and Brain Sciences, The University of Iowa, Iowa City, IA, United States.,Neuroscience and Pharmacology, The University of Iowa, Iowa City, IA, United States.,Health and Human Physiology, The University of Iowa, Iowa City, IA, United States.,The François M. Abboud Cardiovascular Research Center, The University of Iowa, Iowa City, IA, United States
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23
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Abstract
PURPOSE OF REVIEW Obesity increases the risk of hypertension. However, blood pressure decreases before any significant loss of body weight after bariatric surgery. We review the mechanisms of the temporal dissociation between blood pressure and body weight after bariatric surgery. RECENT FINDINGS Restrictive and bypass bariatric surgery lower blood pressure and plasma leptin levels within days of the procedure in both hypertensive and normotensive morbidly obese patients. Rapidly decreasing plasma leptin levels and minimal loss of body weight point to reduced sympathetic nervous system activity as the underlying mechanism of rapid blood pressure decline after bariatric surgery. After the early rapid decline, blood pressure does not decrease further in patients who, while still obese, experience a steady loss of body weight for the subsequent 12 months. The divergent effects of bariatric surgery on blood pressure and body weight query the role of excess body weight in the pathobiology of the obesity phenotype of hypertension. The decrease in blood pressure after bariatric surgery is moderate and independent of body weight. The lack of temporal relationship between blood pressure reduction and loss of body weight for 12 months after sleeve gastrectomy questions the nature of the mechanisms underlying obesity-associated hypertension.
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Affiliation(s)
- Rohan Samson
- Section of Cardiology, John W. Deming Department of Medicine, Tulane University School of Medicine, 1430 Tulane Avenuew, SL-48, New Orleans, LA, 70112, USA
| | - Karnika Ayinapudi
- Section of Cardiology, John W. Deming Department of Medicine, Tulane University School of Medicine, 1430 Tulane Avenuew, SL-48, New Orleans, LA, 70112, USA
| | - Thierry H Le Jemtel
- Section of Cardiology, John W. Deming Department of Medicine, Tulane University School of Medicine, 1430 Tulane Avenuew, SL-48, New Orleans, LA, 70112, USA.
| | - Suzanne Oparil
- Vascular Biology and Hypertension Program, Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
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25
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Abstract
Obesity increases sympathetic nerve activity (SNA) in men, but not women. Here, we review current evidence suggesting that sexually dimorphic sympathoexcitatory responses to leptin and insulin may contribute. More specifically, while insulin increases SNA similarly in lean males and females, this response is markedly amplified in obese males, but is abolished in obese females. In lean female rats, leptin increases a subset of sympathetic nerves only during the high estrogen proestrus reproductive phase; thus, in obese females, because reproductive cycling can become impaired, the sporadic nature of leptin-induced sympathoexcitaton could minimize its action, despite elevated leptin levels. In contrast, in males, obesity preserves or enhances the central sympathoexcitatory response to leptin, and current evidence favors leptin’s contribution to the well-established increases in SNA induced by obesity in men. Leptin and insulin increase SNA via receptor binding in the hypothalamic arcuate nucleus and a neuropathway that includes arcuate neuropeptide Y (NPY) and proopiomelanocortin (POMC) projections to the paraventricular nucleus. These metabolic hormones normally suppress sympathoinhibitory NPY neurons and activate sympathoexcitatory POMC neurons. However, obesity appears to alter the ongoing activity and responsiveness of arcuate NPY and POMC neurons in a sexually dimorphic way, such that SNA increases in males but not females. We propose hypotheses to explain these sex differences and suggest areas of future research.
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Affiliation(s)
- Zhigang Shi
- Department of Physiology and Pharmacology, L-334, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, OR, 97239, USA
| | - Jennifer Wong
- Department of Physiology and Pharmacology, L-334, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, OR, 97239, USA
| | - Virginia L Brooks
- Department of Physiology and Pharmacology, L-334, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, OR, 97239, USA.
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26
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DeLalio LJ, Sved AF, Stocker SD. Sympathetic Nervous System Contributions to Hypertension: Updates and Therapeutic Relevance. Can J Cardiol 2020; 36:712-720. [PMID: 32389344 DOI: 10.1016/j.cjca.2020.03.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 03/02/2020] [Accepted: 03/03/2020] [Indexed: 12/15/2022] Open
Abstract
The sympathetic nervous system plays a pivotal role in the long-term regulation of arterial blood pressure through the ability of the central nervous system to integrate neurohumoral signals and differentially regulate sympathetic neural input to specific end organs. Part 1 of this review will discuss neural mechanisms of salt-sensitive hypertension, obesity-induced hypertension, and the ability of prior experiences to sensitize autonomic networks. Part 2 of this review focuses on new therapeutic advances to treat resistant hypertension including renal denervation and carotid baroactivation. Both advances lower arterial blood pressure by reducing sympathetic outflow. We discuss potential mechanisms and areas of future investigation to target the sympathetic nervous system.
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Affiliation(s)
- Leon J DeLalio
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Alan F Sved
- Department of Neuroscience, University of Pittsburgh, Pennsylvania, USA
| | - Sean D Stocker
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
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27
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Shi Z, Zhao D, Cassaglia PA, Brooks VL. Sites and sources of sympathoexcitation in obese male rats: role of brain insulin. Am J Physiol Regul Integr Comp Physiol 2020; 318:R634-R648. [PMID: 31967846 PMCID: PMC7099464 DOI: 10.1152/ajpregu.00317.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 01/13/2020] [Accepted: 01/13/2020] [Indexed: 12/21/2022]
Abstract
In males, obesity increases sympathetic nerve activity (SNA), but the mechanisms are unclear. Here, we investigate insulin, via an action in the arcuate nucleus (ArcN), and downstream neuropathways, including melanocortin receptor 3/4 (MC3/4R) in the hypothalamic paraventricular nucleus (PVN) and dorsal medial hypothalamus (DMH). We studied conscious and α-chloralose-anesthetized Sprague-Dawley rats fed a high-fat diet, which causes obesity prone (OP) rats to accrue excess fat and obesity-resistant (OR) rats to maintain fat content, similar to rats fed a standard control (CON) diet. Nonspecific blockade of the ArcN with muscimol and specific blockade of ArcN insulin receptors (InsR) decreased lumbar SNA (LSNA), heart rate (HR), and mean arterial pressure (MAP) in OP, but not OR or CON, rats, indicating that insulin supports LSNA in obese males. In conscious rats, intracerebroventricular infusion of insulin increased MAP only in OP rats and also improved HR baroreflex function from subnormal to supranormal. The brain sensitization to insulin may elucidate how insulin can drive central SNA pathways when transport of insulin across the blood-brain barrier may be impaired. Blockade of PVN, but not DMH, MC3/4R with SHU9119 decreased LSNA, HR, and, MAP in OP, but not OR or CON, rats. Interestingly, nanoinjection of the MC3/4R agonist melanotan II (MTII) into the PVN increased LSNA only in OP rats, similar to PVN MTII-induced increases in LSNA in CON rats after blockade of sympathoinhibitory neuropeptide Y Y1 receptors. ArcN InsR expression was not increased in OP rats. Collectively, these data indicate that obesity increases SNA, in part via increased InsR signaling and downstream PVN MC3/4R.
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Affiliation(s)
- Zhigang Shi
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, Oregon
| | - Ding Zhao
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, Oregon
- School of Pharmacy, Hebei Medical University, Shijiazhuang, People's Republic of China
| | - Priscila A Cassaglia
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, Oregon
| | - Virginia L Brooks
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, Oregon
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28
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Hall JE, do Carmo JM, da Silva AA, Wang Z, Hall ME. Obesity, kidney dysfunction and hypertension: mechanistic links. Nat Rev Nephrol 2020; 15:367-385. [PMID: 31015582 DOI: 10.1038/s41581-019-0145-4] [Citation(s) in RCA: 304] [Impact Index Per Article: 76.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Excessive adiposity raises blood pressure and accounts for 65-75% of primary hypertension, which is a major driver of cardiovascular and kidney diseases. In obesity, abnormal kidney function and associated increases in tubular sodium reabsorption initiate hypertension, which is often mild before the development of target organ injury. Factors that contribute to increased sodium reabsorption in obesity include kidney compression by visceral, perirenal and renal sinus fat; increased renal sympathetic nerve activity (RSNA); increased levels of anti-natriuretic hormones, such as angiotensin II and aldosterone; and adipokines, particularly leptin. The renal and neurohormonal pathways of obesity and hypertension are intertwined. For example, leptin increases RSNA by stimulating the central nervous system proopiomelanocortin-melanocortin 4 receptor pathway, and kidney compression and RSNA contribute to renin-angiotensin-aldosterone system activation. Glucocorticoids and/or oxidative stress may also contribute to mineralocorticoid receptor activation in obesity. Prolonged obesity and progressive renal injury often lead to the development of treatment-resistant hypertension. Patient management therefore often requires multiple antihypertensive drugs and concurrent treatment of dyslipidaemia, insulin resistance, diabetes and inflammation. If more effective strategies for the prevention and control of obesity are not developed, cardiorenal, metabolic and other obesity-associated diseases could overwhelm health-care systems in the future.
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Affiliation(s)
- John E Hall
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA. .,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, USA.
| | - Jussara M do Carmo
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, USA
| | - Alexandre A da Silva
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, USA
| | - Zhen Wang
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, USA
| | - Michael E Hall
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, USA.,Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
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29
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Abstract
Despite availability of effective drugs for hypertension therapy, significant numbers of hypertensive patients fail to achieve recommended blood pressure levels on ≥3 antihypertensive drugs of different classes. These individuals have a high prevalence of adverse cardiovascular events and are defined as having resistant hypertension (RHT) although nonadherence to prescribed antihypertensive medications is common in patients with apparent RHT. Furthermore, apparent and true RHT often display increased sympathetic activity. Based on these findings, technology was developed to treat RHT by suppressing sympathetic activity with electrical stimulation of the carotid baroreflex and catheter-based renal denervation (RDN). Over the last 15 years, experimental and clinical studies have provided better understanding of the physiological mechanisms that account for blood pressure lowering with baroreflex activation and RDN and, in so doing, have provided insight into which patients in this heterogeneous hypertensive population are most likely to respond favorably to these device-based therapies. Experimental studies have also played a role in modifying device technology after early clinical trials failed to meet key endpoints for safety and efficacy. At the same time, these studies have exposed potential differences between baroreflex activation and RDN and common challenges that will likely impact antihypertensive treatment and clinical outcomes in patients with RHT. In this review, we emphasize physiological studies that provide mechanistic insights into blood pressure lowering with baroreflex activation and RDN in the context of progression of clinical studies, which are now at a critical point in determining their fate in RHT management.
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Affiliation(s)
- Thomas E Lohmeier
- From the Department of Physiology and Biophysics (T.E.L., J.E.H.), University of Mississippi Medical Center, Jackson
| | - John E Hall
- From the Department of Physiology and Biophysics (T.E.L., J.E.H.), University of Mississippi Medical Center, Jackson.,Mississippi Center for Obesity Research (J.E.H.), University of Mississippi Medical Center, Jackson
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30
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Association of general and central adiposity with blood pressure among Chinese adults: results from the China National Stroke Prevention Project. J Hypertens 2019; 36:2406-2413. [PMID: 30020239 DOI: 10.1097/hjh.0000000000001852] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The American Heart Association concluded that waist circumference was a better predictor of blood pressure risk than BMI in Asians. However, data are inconsistent and information in Chinese, the largest global population group, is limited. METHODS Data was obtained from the Chinese National Stroke Prevention Project Survey of a nationally representative sample of middle-aged and older Chinese adults. A total of 135 825 individuals not taking any antihypertensive drugs were included in this study. Multiple linear regression analyses were conducted to examine the association between blood pressure and parameters of general adiposity, including BMI, height-adjusted weight, and parameters of central adiposity, including waist circumference, hip circumference, waist-hip ratio, and waist-height ratio. Results were shown as mean difference in blood pressure associated with one standard deviation higher level of adiposity. RESULTS The overall means ± standard deviation of BMI and waist circumference were 24.3 ± 3.18 kg/m and 84.0 ± 8.88 cm, respectively. BMI seemed more strongly associated with SBP/DBP (4.22 mmHg/SD; 2.60 mmHg/SD) than central adiposity markers. In addition, there were sex differences. For men, waist circumference showed a stronger association with SBP/DBP than BMI (4.04 vs. 3.79, P < 0.05; 2.26 vs. 2.13, P < 0.05). For women, BMI was more closely related to SBP/DBP than central adiposity parameters, such as waist circumference (4.59 vs. 3.41, P < 0.05; 2.98 vs. 2.24, P < 0.05). Additionally, in both urban and rural areas, waist circumference was mostly associated with SBP/DBP among men, whereas it was BMI among women. CONCLUSION Compared with central adiposity, blood pressure is more strongly associated with general adiposity in Chinese adults. Interestingly, there are significant sex differences in the relationship of blood pressure with general and central adiposity. Waist circumference is the strongest predictor for men but suboptimal for women, and BMI tend to a better predictor of blood pressure for women. In addition, our results for men are consistent with the recommendation of the American Heart Association in 2015 that waist circumference could be used for assessing the risk of blood pressure.
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31
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Lambert EA, Esler MD, Schlaich MP, Dixon J, Eikelis N, Lambert GW. Obesity-Associated Organ Damage and Sympathetic Nervous Activity. Hypertension 2019; 73:1150-1159. [DOI: 10.1161/hypertensionaha.118.11676] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Elisabeth A. Lambert
- From the Iverson Health Innovation Research Institute and School of Health Sciences, Faculty of Health, Arts and Design, Swinburne University of Technology, Hawthorn, VIC, Australia (E.A.L., N.E., G.W.L.)
- Human Neurotransmitters Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia (E.A.L., M.D.E., N.E., G.W.L.)
| | - Murray D. Esler
- Human Neurotransmitters Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia (E.A.L., M.D.E., N.E., G.W.L.)
| | - Markus P. Schlaich
- Dobney Hypertension Centre, School of Medicine–Royal Perth Hospital Unit, University of Western Australia (M.P.S.)
| | - John Dixon
- Clinical Obesity Research Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia (J.D.)
| | - Nina Eikelis
- From the Iverson Health Innovation Research Institute and School of Health Sciences, Faculty of Health, Arts and Design, Swinburne University of Technology, Hawthorn, VIC, Australia (E.A.L., N.E., G.W.L.)
| | - Gavin W. Lambert
- From the Iverson Health Innovation Research Institute and School of Health Sciences, Faculty of Health, Arts and Design, Swinburne University of Technology, Hawthorn, VIC, Australia (E.A.L., N.E., G.W.L.)
- Human Neurotransmitters Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia (E.A.L., M.D.E., N.E., G.W.L.)
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AlMarabeh S, Abdulla MH, O'Halloran KD. Is Aberrant Reno-Renal Reflex Control of Blood Pressure a Contributor to Chronic Intermittent Hypoxia-Induced Hypertension? Front Physiol 2019; 10:465. [PMID: 31105584 PMCID: PMC6491928 DOI: 10.3389/fphys.2019.00465] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 04/04/2019] [Indexed: 12/16/2022] Open
Abstract
Renal sensory nerves are important in the regulation of body fluid and electrolyte homeostasis, and blood pressure. Activation of renal mechanoreceptor afferents triggers a negative feedback reno-renal reflex that leads to the inhibition of sympathetic nervous outflow. Conversely, activation of renal chemoreceptor afferents elicits reflex sympathoexcitation. Dysregulation of reno-renal reflexes by suppression of the inhibitory reflex and/or activation of the excitatory reflex impairs blood pressure control, predisposing to hypertension. Obstructive sleep apnoea syndrome (OSAS) is causally related to hypertension. Renal denervation in patients with OSAS or in experimental models of chronic intermittent hypoxia (CIH), a cardinal feature of OSAS due to recurrent apnoeas (pauses in breathing), results in a decrease in circulating norepinephrine levels and attenuation of hypertension. The mechanism of the beneficial effect of renal denervation on blood pressure control in models of CIH and OSAS is not fully understood, since renal denervation interrupts renal afferent signaling to the brain and sympathetic efferent signals to the kidneys. Herein, we consider the currently proposed mechanisms involved in the development of hypertension in CIH disease models with a focus on oxidative and inflammatory mediators in the kidneys and their potential influence on renal afferent control of blood pressure, with wider consideration of the evidence available from a variety of hypertension models. We draw focus to the potential contribution of aberrant renal afferent signaling in the development, maintenance and progression of high blood pressure, which may have relevance to CIH-induced hypertension.
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Affiliation(s)
- Sara AlMarabeh
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Mohammed H Abdulla
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
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33
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Tófolo LP, Rinaldi W, Gôngora AB, Matiusso CCI, Pavanello A, Malta A, de Almeida DL, Ribeiro TA, Oliveira AR, Peres MNC, Armitage JA, Mathias PCDF, Palma-Rigo K. Moderate Physical Training Ameliorates Cardiovascular Dysfunction Induced by High Fat Diet After Cessation of Training in Adult Rats. Front Physiol 2019; 10:170. [PMID: 30930783 PMCID: PMC6423496 DOI: 10.3389/fphys.2019.00170] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 02/12/2019] [Indexed: 12/11/2022] Open
Abstract
We aimed to test whether moderate physical training can induce long-lasting protection against cardiovascular risk factors induced by high fat diet (HFD) intake, even after cessation of training. 90-days-old Wistar rats were submitted to a sedentary lifestyle or moderate physical training, three times a week, for 30 days. Following this, at 120 days-of age, sedentary and trained rats received a hypercaloric diet (HFD) or a commercial diet normal fat diet (NFD) for 30 days. Body weight (BW) and food intake were evaluated weekly. At 150 days-of age, hemodynamic measures (systolic, diastolic, mean blood pressure, pulse pressure, pulse interval and heart rate) were made via an indwelling femoral artery catheter. Beat-to-beat data were analyzed to calculate power spectra of systolic blood pressure (SBP) and pulse interval. After euthanasia, mesenteric fat pads were removed and weighted and total blood was stored for later analysis of lipid profile. Consumption of a HFD increased blood pressure (BP), pulse pressure, low frequency BP variability, BW gain, fat pad stores and induced dyslipidemia. Interestingly, prior physical training was able to partially protect against this rise in BP and body fat stores. Prior physical training did not totally protect against the effects of HFD consumption but previously trained animals did demonstrate resistance to the development of cardiometabolic alterations, which illustrate that the benefits of physical training may be partially maintained even after 30 days of detraining period.
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Affiliation(s)
- Laize Peron Tófolo
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringá, Maringá, Brazil.,Department of Physical Education, Faculty of Biomedical Sciences of Cacoal, Cacoal, Brazil
| | - Wilson Rinaldi
- Department of Physical Education, State University of Maringá, Maringá, Brazil
| | - Adriane Barreto Gôngora
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringá, Maringá, Brazil
| | - Camila Cristina Ianoni Matiusso
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringá, Maringá, Brazil
| | - Audrei Pavanello
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringá, Maringá, Brazil
| | - Ananda Malta
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringá, Maringá, Brazil
| | - Douglas Lopes de Almeida
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringá, Maringá, Brazil
| | - Tatiane Aparecida Ribeiro
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringá, Maringá, Brazil
| | | | - Maria Natalia Chimirri Peres
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringá, Maringá, Brazil
| | | | - Paulo Cezar de Freitas Mathias
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringá, Maringá, Brazil
| | - Kesia Palma-Rigo
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringá, Maringá, Brazil.,Faculdade Adventista Paranaense, Ivatuba, Brazil
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34
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Abstract
The causes of essential hypertension remain an enigma. Interactions between genetic and external factors are generally recognized to act as aetiological mechanisms that trigger the pathogenesis of high blood pressure. However, the questions of which genes and factors are involved, and when and where such interactions occur, remain unresolved. Emerging evidence indicates that the hypertensive response to pressor stimuli, like many other physiological and behavioural adaptations, can become sensitized to particular stimuli. Studies in animal models show that, similarly to other response systems controlled by the brain, hypertensive response sensitization (HTRS) is mediated by neuroplasticity. The brain circuitry involved in HTRS controls the sympathetic nervous system. This Review outlines evidence supporting the phenomenon of HTRS and describes the range of physiological and psychosocial stressors that can produce a sensitized hypertensive state. Also discussed are the cellular and molecular changes in the brain neural network controlling sympathetic tone involved in long-term storage of information relating to stressors, which could serve to maintain a sensitized state. Finally, this Review concludes with a discussion of why a sensitized hypertensive response might previously have been beneficial and increased biological fitness under some environmental conditions and why today it has become a health-related liability.
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Affiliation(s)
- Alan Kim Johnson
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, USA.
- Department of Health and Human Physiology, University of Iowa, Iowa City, IA, USA.
- Department of Pharmacology, University of Iowa, Iowa City, IA, USA.
- The François M. Abboud Cardiovascular Center, Iowa City, IA, USA.
| | - Baojian Xue
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, USA
- The François M. Abboud Cardiovascular Center, Iowa City, IA, USA
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Nizar JM, Shepard BD, Vo VT, Bhalla V. Renal tubule insulin receptor modestly promotes elevated blood pressure and markedly stimulates glucose reabsorption. JCI Insight 2018; 3:95107. [PMID: 30135311 DOI: 10.1172/jci.insight.95107] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 07/03/2018] [Indexed: 12/25/2022] Open
Abstract
Although the cause of hypertension among individuals with obesity and insulin resistance is unknown, increased plasma insulin, acting in the kidney to increase sodium reabsorption, has been proposed as a potential mechanism. Insulin may also stimulate glucose uptake, but the contributions of tubular insulin signaling to sodium or glucose transport in the setting of insulin resistance is unknown. To directly study the role of insulin signaling in the kidney, we generated inducible renal tubule-specific insulin receptor-KO mice and used high-fat feeding and mineralocorticoids to model obesity and insulin resistance. Insulin receptor deletion did not alter blood pressure or sodium excretion in mice on a high-fat diet alone, but it mildly attenuated the increase in blood pressure with mineralocorticoid supplementation. Under these conditions, KO mice developed profound glucosuria. Insulin receptor deletion significantly reduced SGLT2 expression and increased urinary glucose excretion and urine flow. These data demonstrate a direct role for insulin receptor-stimulated sodium and glucose transport and a functional interaction of insulin signaling with mineralocorticoids in vivo. These studies uncover a potential mechanistic link between preserved insulin sensitivity and renal glucose handling in obesity and insulin resistance.
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Affiliation(s)
- Jonathan M Nizar
- Division of Nephrology, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Blythe D Shepard
- Department of Human Science, Georgetown University, Washington, DC
| | - Vianna T Vo
- Division of Nephrology, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Vivek Bhalla
- Division of Nephrology, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
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Le Jemtel TH, Samson R, Milligan G, Jaiswal A, Oparil S. Visceral Adipose Tissue Accumulation and Residual Cardiovascular Risk. Curr Hypertens Rep 2018; 20:77. [PMID: 29992362 DOI: 10.1007/s11906-018-0880-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE OF THE REVIEW Low-grade systemic inflammation increases residual cardiovascular risk. The pathogenesis of low-grade systemic inflammation is not well understood. RECENT FINDINGS Visceral adipose tissue accumulates when the subcutaneous adipose tissue can no longer store excess nutrients. Visceral adipose tissue inflammation initially facilitates storage of nutrients but with time become maladaptive and responsible for low-grade systemic inflammation. Control of low-grade systemic inflammation requires reversal of visceral adipose tissue accumulation with intense and sustained aerobic exercise or bariatric surgery. Alternatively, pharmacologic inhibition of the inflammatory signaling pathway may be considered. Reversal visceral adipose tissue accumulation lowers residual cardiovascular risk.
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Affiliation(s)
- Thierry H Le Jemtel
- Division of Cardiology, Tulane University School of Medicine, 1430 Tulane Avenue, SL-48, New Orleans, LA, 70112, USA.
| | - Rohan Samson
- Division of Cardiology, Tulane University School of Medicine, 1430 Tulane Avenue, SL-48, New Orleans, LA, 70112, USA
| | - Gregory Milligan
- Division of Cardiology, Tulane University School of Medicine, 1430 Tulane Avenue, SL-48, New Orleans, LA, 70112, USA
| | - Abhishek Jaiswal
- Department of Cardiology, Hartford Hospital, 85 Jefferson Street, Suite 208, Hartford, CT, 06106, USA
| | - Suzanne Oparil
- Vascular Biology and Hypertension Program, Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Birmingham, USA
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Leptin injection into the left stellate ganglion augments ischemia-related ventricular arrhythmias via sympathetic nerve activation. Heart Rhythm 2018; 15:597-606. [DOI: 10.1016/j.hrthm.2017.12.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Indexed: 12/22/2022]
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Abstract
PURPOSE OF REVIEW The major health issue of being overweight or obese relates to the development of hypertension, insulin resistance and diabetic complications. One of the major underlying factors influencing the elevated blood pressure in obesity is increased activity of the sympathetic nerves to particular organs such as the kidney. RECENT FINDINGS There is now convincing evidence from animal studies that major signals such as leptin and insulin have a sympathoexcitatory action in the hypothalamus to cause hypertension. Recent studies suggest that this may involve 'neural plasticity' within hypothalamic signalling driven by central actions of leptin mediated via activation of melanocortin receptor signalling and activation of brain neurotrophic factors. This review describes the evidence to support the contribution of the SNS to obesity related hypertension and the major metabolic and adipokine signals.
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Stocker SD, Kinsman BJ, Sved AF. Recent Advances in Neurogenic Hypertension: Dietary Salt, Obesity, and Inflammation. Hypertension 2017; 70:HYPERTENSIONAHA.117.08936. [PMID: 28739972 PMCID: PMC5783795 DOI: 10.1161/hypertensionaha.117.08936] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Neurally-mediated hypertension results from a dysregulation of sympathetic and/or neuroendocrine mechanisms to increase ABP. Multiple factors may exert multiple central effects to alter neural circuits and produce unique sympathetic signatures and elevate ABP. In this brief review, we have discussed novel observations regarding three contributing factors: dietary salt intake, obesity, and inflammation. However, the interaction among these and other factors is likely much more complex; recent studies suggest a prior exposure to one stimulus may sensitize the response to a subsequent hypertensive stimulus. Insight into the central mechanisms by which these factors selectively alter SNA or cooperatively interact to impact hypertension may represent a platform for novel therapeutic treatment strategies.
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Affiliation(s)
- Sean D Stocker
- From the Department of Medicine, Renal-Electrolyte Division (S.D.S., B.J.K.), Department of Neuroscience (A.F.S.), and University of Pittsburgh Hypertension Center (S.D.S.), University of Pittsburgh, PA.
| | - Brian J Kinsman
- From the Department of Medicine, Renal-Electrolyte Division (S.D.S., B.J.K.), Department of Neuroscience (A.F.S.), and University of Pittsburgh Hypertension Center (S.D.S.), University of Pittsburgh, PA
| | - Alan F Sved
- From the Department of Medicine, Renal-Electrolyte Division (S.D.S., B.J.K.), Department of Neuroscience (A.F.S.), and University of Pittsburgh Hypertension Center (S.D.S.), University of Pittsburgh, PA
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Renal denervation and hypertension - The need to investigate unintended effects and neural control of the human kidney. Auton Neurosci 2017; 204:119-125. [DOI: 10.1016/j.autneu.2016.08.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 08/01/2016] [Accepted: 08/02/2016] [Indexed: 01/22/2023]
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Zhang X, Lerman LO. The metabolic syndrome and chronic kidney disease. Transl Res 2017; 183:14-25. [PMID: 28025032 PMCID: PMC5393937 DOI: 10.1016/j.trsl.2016.12.004] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/22/2016] [Accepted: 12/02/2016] [Indexed: 02/07/2023]
Abstract
The metabolic syndrome (MetS) is a cluster of cardiovascular risk factors including insulin resistance (IR), dyslipidemia, and hypertension, which may also foster development of chronic kidney disease. The mechanisms of MetS-induced kidney disease are not fully understood. The purpose of this review is to summarize recent discoveries regarding the impact of MetS on the kidney, particularly on the renal microvasculature and cellular mitochondria. Fundamental manifestations of MetS include IR and adipose tissue expansion, the latter promoting chronic inflammation and oxidative stress that exacerbate IR. Those in turn can elicit various kidney injurious events through endothelial dysfunction, activation of the renin-angiotensin-aldosterone system, and adipokine imbalance. Inflammation and IR are also major contributors to microvascular remodeling and podocyte injury. Hence, these events may result in hypertension, albuminuria, and parenchymal damage. In addition, dyslipidemia and excessive nutrient availability may impair mitochondrial function and thereby promote progression of kidney cell damage. Elucidation of the link between MetS and kidney injury may help develop preventative measures and possibly novel therapeutic targets to alleviate and avert development of renal manifestations.
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Affiliation(s)
- Xin Zhang
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minn
| | - Lilach O Lerman
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minn.
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Hart EC, Head GA, Carter JR, Wallin BG, May CN, Hamza SM, Hall JE, Charkoudian N, Osborn JW. Recording sympathetic nerve activity in conscious humans and other mammals: guidelines and the road to standardization. Am J Physiol Heart Circ Physiol 2017; 312:H1031-H1051. [PMID: 28364017 DOI: 10.1152/ajpheart.00703.2016] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 03/06/2017] [Accepted: 03/06/2017] [Indexed: 01/03/2023]
Abstract
Over the past several decades, studies of the sympathetic nervous system in humans, sheep, rabbits, rats, and mice have substantially increased mechanistic understanding of cardiovascular function and dysfunction. Recently, interest in sympathetic neural mechanisms contributing to blood pressure control has grown, in part because of the development of devices or surgical procedures that treat hypertension by manipulating sympathetic outflow. Studies in animal models have provided important insights into physiological and pathophysiological mechanisms that are not accessible in human studies. Across species and among laboratories, various approaches have been developed to record, quantify, analyze, and interpret sympathetic nerve activity (SNA). In general, SNA demonstrates "bursting" behavior, where groups of action potentials are synchronized and linked to the cardiac cycle via the arterial baroreflex. In humans, it is common to quantify SNA as bursts per minute or bursts per 100 heart beats. This type of quantification can be done in other species but is only commonly reported in sheep, which have heart rates similar to humans. In rabbits, rats, and mice, SNA is often recorded relative to a maximal level elicited in the laboratory to control for differences in electrode position among animals or on different study days. SNA in humans can also be presented as total activity, where normalization to the largest burst is a common approach. The goal of the present paper is to put together a summary of "best practices" in several of the most common experimental models and to discuss opportunities and challenges relative to the optimal measurement of SNA across species.Listen to this article's corresponding podcast at https://ajpheart.podbean.com/e/guidelines-for-measuring-sympathetic-nerve-activity/.
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Affiliation(s)
- Emma C Hart
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom;
| | - Geoffrey A Head
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | | | | | - Clive N May
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | | | - John E Hall
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, Mississippi
| | - Nisha Charkoudian
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts; and
| | - John W Osborn
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
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Abstract
The objective of this review is to provide an in-depth evaluation of how renal nerves regulate renal and cardiovascular function with a focus on long-term control of arterial pressure. We begin by reviewing the anatomy of renal nerves and then briefly discuss how the activity of renal nerves affects renal function. Current methods for measurement and quantification of efferent renal-nerve activity (ERNA) in animals and humans are discussed. Acute regulation of ERNA by classical neural reflexes as well and hormonal inputs to the brain is reviewed. The role of renal nerves in long-term control of arterial pressure in normotensive and hypertensive animals (and humans) is then reviewed with a focus on studies utilizing continuous long-term monitoring of arterial pressure. This includes a review of the effect of renal-nerve ablation on long-term control of arterial pressure in experimental animals as well as humans with drug-resistant hypertension. The extent to which changes in arterial pressure are due to ablation of renal afferent or efferent nerves are reviewed. We conclude by discussing the importance of renal nerves, relative to sympathetic activity to other vascular beds, in long-term control of arterial pressure and hypertension and propose directions for future research in this field. © 2017 American Physiological Society. Compr Physiol 7:263-320, 2017.
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Affiliation(s)
- John W Osborn
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| | - Jason D Foss
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, USA
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Morais RL, Hilzendeger AM, Visniauskas B, Todiras M, Alenina N, Mori MA, Araújo RC, Nakaie CR, Chagas JR, Carmona AK, Bader M, Pesquero JB. High aminopeptidase A activity contributes to blood pressure control in ob/ob mice by AT 2 receptor-dependent mechanism. Am J Physiol Heart Circ Physiol 2016; 312:H437-H445. [PMID: 27940965 DOI: 10.1152/ajpheart.00485.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 12/05/2016] [Accepted: 12/06/2016] [Indexed: 11/22/2022]
Abstract
Obesity is assumed to be a major cause of human essential hypertension; however, the mechanisms responsible for weight-related increase in blood pressure (BP) are not fully understood. The prevalence of hypertension induced by obesity has grown over the years, and the role of the renin-angiotensin-aldosterone system (RAAS) in this process continues to be elucidated. In this scenario, the ob/ob mice are a genetic obesity model generally used for metabolic disorder studies. These mice are normotensive even though they present several metabolic conditions that predispose them to hypertension. Although the normotensive trait in these mice is associated with the poor activation of sympathetic nervous system by the lack of leptin, we demonstrated that ob/ob mice present massively increased aminopeptidase A (APA) activity in the circulation. APA enzyme metabolizes angiotensin (ANG) II into ANG III, a peptide associated with intrarenal angiotensin type 2 (AT2) receptor activation and induction of natriuresis. In these mice, we found increased ANG-III levels in the circulation, high AT2 receptor expression in the kidney, and enhanced natriuresis. AT2 receptor blocking and APA inhibition increased BP, suggesting the ANG III-AT2 receptor axis as a complementary BP control mechanism. Circulating APA activity was significantly reduced by weight loss independently of leptin, indicating the role of fat tissue in APA production. Therefore, in this study we provide new data supporting the role of APA in BP control in ob/ob mouse strain. These findings improve our comprehension about obesity-related hypertension and suggest new tools for its treatment.NEW & NOTEWORTHY In this study, we reported an increased angiotensin III generation in the circulation of ob/ob mice caused by a high aminopeptidase A activity. These findings are associated with an increased natriuresis found in these mice and support the role of renin-angiotensin-aldosterone system as additional mechanism regulating blood pressure in this genetic obese strain.
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Affiliation(s)
- Rafael L Morais
- Departamento de Biofísica, Universidade Federal de São Paulo, Campus São Paulo, São Paulo, Brazil
| | - Aline M Hilzendeger
- Departamento de Biofísica, Universidade Federal de São Paulo, Campus São Paulo, São Paulo, Brazil
| | - Bruna Visniauskas
- Departamento de Psicobiologia, Universidade Federal de São Paulo, Campus São Paulo, São Paulo, Brazil
| | - Mihail Todiras
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | | | - Marcelo A Mori
- Departamento de Biofísica, Universidade Federal de São Paulo, Campus São Paulo, São Paulo, Brazil
| | - Ronaldo C Araújo
- Departamento de Biofísica, Universidade Federal de São Paulo, Campus São Paulo, São Paulo, Brazil
| | - Clovis R Nakaie
- Departamento de Biofísica, Universidade Federal de São Paulo, Campus São Paulo, São Paulo, Brazil
| | - Jair R Chagas
- Departamento de Psicobiologia, Universidade Federal de São Paulo, Campus São Paulo, São Paulo, Brazil
| | - Adriana K Carmona
- Departamento de Biofísica, Universidade Federal de São Paulo, Campus São Paulo, São Paulo, Brazil
| | - Michael Bader
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany.,Charité University Medicine Berlin, Berlin, Germany.,German Center for Cardiovascular Research, Berlin, Germany; and.,Institute for Biology, University of Lübeck, Lübeck, Germany
| | - João B Pesquero
- Departamento de Biofísica, Universidade Federal de São Paulo, Campus São Paulo, São Paulo, Brazil;
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Abstract
Hypertension and associated cardiovascular diseases represent the most common health complication of obesity and the leading cause of morbidity and mortality in overweight and obese patients. Emerging evidence suggests a critical role for the central nervous system particularly the brain action of the adipocyte-derived hormone leptin in linking obesity and hypertension. The preserved ability of leptin to cause cardiovascular sympathetic nerve activation despite the resistance to the metabolic actions of the hormone appears essential in this pathological process. This review describes the evidence supporting the neurogenic bases for obesity-associated hypertension with a particular focus on the neuronal and molecular signaling pathways underlying leptin's effects on sympathetic nerve activity and blood pressure.
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Affiliation(s)
- Balyssa B Bell
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, USA.
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Briant LJB, Charkoudian N, Hart EC. Sympathetic regulation of blood pressure in normotension and hypertension: when sex matters. Exp Physiol 2016; 101:219-29. [PMID: 26682826 DOI: 10.1113/ep085368] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/14/2015] [Indexed: 12/21/2022]
Abstract
NEW FINDINGS What is the topic of this review? Hypertension is a major problem in Western society. Risk of hypertension increases with age, especially in women, who have lower risk compared with men until menopause. This review outlines the sex differences in the sympathetic control of blood pressure and how these mechanisms change with age. What advances does it highlight? It has recently been recognized that men and women regulate blood pressure by different physiological mechanisms. This is important for both the understanding and the clinical management of individual patients with hypertension. This review summarizes recent advances in understanding how the regulation of blood pressure in hypertension by the sympathetic nervous system differs between men and women. The sympathetic nervous system has a central role in the regulation of arterial blood pressure (BP) and in the development of hypertension in humans. Recent evidence points to differences between the sexes in the integrative mechanisms by which BP is controlled, suggesting that the development of hypertension may follow distinct pathways in women compared with men. An important aspect of sympathetic control of BP is its substantial interindividual variability. In healthy young men, the variability in sympathetic nerve activity (SNA) is balanced by variability in cardiac output and vascular adrenergic responses, such that BP remains similar, and normal, across a severalfold range of resting SNA values. In young women, variability in resting SNA is similar to that seen in men, but the 'balancing' mechanisms are strikingly different; women exhibit greater β-adrenergic vasodilatation compared with men, which minimizes the pressor effects of a given level of SNA. Ageing is associated with increased SNA and a loss of the balancing factors seen in younger people, leading to an increased risk of hypertension in older people. Loss of oestrogen with menopause in women appears to be linked mechanistically with the decrease in β-adrenergic vasodilatation and the increased risk of hypertension in older women. Other important factors contributing to hypertension via sympathetic mechanisms are obesity and arterial stiffening, both of which increase with ageing. We conclude with a discussion of important areas in which more work is needed to understand and manage appropriately the sex-specific mechanisms in the development and maintenance of hypertension.
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Affiliation(s)
- L J B Briant
- Clinical Research and Imaging Centre, Cardionomics Group, University of Bristol, Bristol, UK
| | - N Charkoudian
- US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - E C Hart
- Clinical Research and Imaging Centre, Cardionomics Group, University of Bristol, Bristol, UK
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Richter VFI, Briffa JF, Moritz KM, Wlodek ME, Hryciw DH. The role of maternal nutrition, metabolic function and the placenta in developmental programming of renal dysfunction. Clin Exp Pharmacol Physiol 2016; 43:135-41. [PMID: 26475203 DOI: 10.1111/1440-1681.12505] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 09/21/2015] [Accepted: 10/12/2015] [Indexed: 11/27/2022]
Abstract
The intrauterine environment is critical for the development of the foetus. Barker and colleagues were the first to identify that adverse perturbations during foetal development are associated with an increased risk of developing diseases in adulthood, including cardiorenal disease. Specifically for the kidney, perturbations in utero can lead to nephron deficits and renal dysfunction by a number of mechanisms. Altered programming of nephron number is associated with an increased risk of developing kidney disease via glomerular hypertrophy and reduced vasodilative capacity of the renal blood vessels; both of which would contribute to hypertension in adulthood, with males being more susceptible to disease outcomes. Additionally, alterations in the renin-angiotensin system (RAS) such as an upregulation or downregulation of specific receptors, depending on the nature of the insult, have also been implicated in the development of renal dysfunction. Sex-specific differences in the expression of the RAS during late gestation and in the early postnatal environment have also been identified. Extensive research has demonstrated that both uteroplacental insufficiency and maternal malnutrition alter renal development in utero. Equally, exposure to maternal diabetes and maternal obesity during development are also associated with an increased risk of developing renal disease, however, the mechanism behind this association is poorly understood. Therefore, identifying the link between an adverse intrauterine environment and the programmed kidney disease risk in adulthood may facilitate the development of strategies to alleviate the epidemics of cardiorenal disease worldwide, in addition to understanding why males are more susceptible to adult-onset cardiovascular diseases.
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Affiliation(s)
- V F I Richter
- Department of Physiology, The University of Melbourne, Parkville, Vic., Australia
| | - J F Briffa
- Department of Physiology, The University of Melbourne, Parkville, Vic., Australia
| | - K M Moritz
- School of Biomedical Sciences, University of Queensland, St. Lucia, Qld, Australia
| | - M E Wlodek
- Department of Physiology, The University of Melbourne, Parkville, Vic., Australia
| | - D H Hryciw
- Department of Physiology, The University of Melbourne, Parkville, Vic., Australia
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Asirvatham-Jeyaraj N, Fiege JK, Han R, Foss J, Banek CT, Burbach BJ, Razzoli M, Bartolomucci A, Shimizu Y, Panoskaltsis-Mortari A, Osborn JW. Renal Denervation Normalizes Arterial Pressure With No Effect on Glucose Metabolism or Renal Inflammation in Obese Hypertensive Mice. Hypertension 2016; 68:929-36. [PMID: 27550916 PMCID: PMC5016252 DOI: 10.1161/hypertensionaha.116.07993] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 07/31/2016] [Indexed: 12/18/2022]
Abstract
Hypertension often occurs in concurrence with obesity and diabetes mellitus, commonly referred to as metabolic syndrome. Renal denervation (RDNx) lowers arterial pressure (AP) and improves glucose metabolism in drug-resistant hypertensive patients with high body mass index. In addition, RDNx has been shown to reduce renal inflammation in the mouse model of angiotensin II hypertension. The present study tested the hypothesis that RDNx reduces AP and renal inflammation and improves glucose metabolism in obesity-induced hypertension. Eight-week-old C57BL/6J mice were fed either a low-fat diet (10 kcal%) or a high-fat diet (45 kcal%) for 10 weeks. Body weight, food intake, fasting blood glucose, and glucose metabolism (glucose tolerance test) were measured. In a parallel study, radiotelemeters were implanted in mice for AP measurement. High fat-fed C57BL/6J mice exhibited an inflammatory and metabolic syndrome phenotype, including increased fat mass, increased AP, and hyperglycemia compared with low-fat diet mice. RDNx, but not Sham surgery, normalized AP in high-fat diet mice (115.8±1.5 mm Hg in sham versus 96.6±6.7 mm Hg in RDNx). RDNx had no significant effect on AP in low-fat diet mice. Also, RDNx had no significant effect on glucose metabolism or renal inflammation as measured by the number of CD8, CD4, and T helper cells or levels of inflammatory cytokines in the kidneys. These results indicate that although renal nerves play a role in obesity-induced hypertension, they do not contribute to impaired glucose metabolism or renal inflammation in this model.
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Affiliation(s)
- Ninitha Asirvatham-Jeyaraj
- From the Department of Integrative Biology and Physiology (N.A.-J., R.H., J.F., C.T.B., M.R., A.B., J.W.O.), Laboratory Medicine and Pathology (J.K.F., B.J.B., Y.S.), and Pediatrics (A.P.-M.), University of Minnesota, Minneapolis
| | - Jessica K Fiege
- From the Department of Integrative Biology and Physiology (N.A.-J., R.H., J.F., C.T.B., M.R., A.B., J.W.O.), Laboratory Medicine and Pathology (J.K.F., B.J.B., Y.S.), and Pediatrics (A.P.-M.), University of Minnesota, Minneapolis
| | - Ruijun Han
- From the Department of Integrative Biology and Physiology (N.A.-J., R.H., J.F., C.T.B., M.R., A.B., J.W.O.), Laboratory Medicine and Pathology (J.K.F., B.J.B., Y.S.), and Pediatrics (A.P.-M.), University of Minnesota, Minneapolis
| | - Jason Foss
- From the Department of Integrative Biology and Physiology (N.A.-J., R.H., J.F., C.T.B., M.R., A.B., J.W.O.), Laboratory Medicine and Pathology (J.K.F., B.J.B., Y.S.), and Pediatrics (A.P.-M.), University of Minnesota, Minneapolis
| | - Christopher T Banek
- From the Department of Integrative Biology and Physiology (N.A.-J., R.H., J.F., C.T.B., M.R., A.B., J.W.O.), Laboratory Medicine and Pathology (J.K.F., B.J.B., Y.S.), and Pediatrics (A.P.-M.), University of Minnesota, Minneapolis
| | - Brandon J Burbach
- From the Department of Integrative Biology and Physiology (N.A.-J., R.H., J.F., C.T.B., M.R., A.B., J.W.O.), Laboratory Medicine and Pathology (J.K.F., B.J.B., Y.S.), and Pediatrics (A.P.-M.), University of Minnesota, Minneapolis
| | - Maria Razzoli
- From the Department of Integrative Biology and Physiology (N.A.-J., R.H., J.F., C.T.B., M.R., A.B., J.W.O.), Laboratory Medicine and Pathology (J.K.F., B.J.B., Y.S.), and Pediatrics (A.P.-M.), University of Minnesota, Minneapolis
| | - Alessandro Bartolomucci
- From the Department of Integrative Biology and Physiology (N.A.-J., R.H., J.F., C.T.B., M.R., A.B., J.W.O.), Laboratory Medicine and Pathology (J.K.F., B.J.B., Y.S.), and Pediatrics (A.P.-M.), University of Minnesota, Minneapolis
| | - Yoji Shimizu
- From the Department of Integrative Biology and Physiology (N.A.-J., R.H., J.F., C.T.B., M.R., A.B., J.W.O.), Laboratory Medicine and Pathology (J.K.F., B.J.B., Y.S.), and Pediatrics (A.P.-M.), University of Minnesota, Minneapolis
| | - Angela Panoskaltsis-Mortari
- From the Department of Integrative Biology and Physiology (N.A.-J., R.H., J.F., C.T.B., M.R., A.B., J.W.O.), Laboratory Medicine and Pathology (J.K.F., B.J.B., Y.S.), and Pediatrics (A.P.-M.), University of Minnesota, Minneapolis
| | - John W Osborn
- From the Department of Integrative Biology and Physiology (N.A.-J., R.H., J.F., C.T.B., M.R., A.B., J.W.O.), Laboratory Medicine and Pathology (J.K.F., B.J.B., Y.S.), and Pediatrics (A.P.-M.), University of Minnesota, Minneapolis.
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Central proopiomelanocortin but not neuropeptide Y mediates sympathoexcitation and hypertension in fat fed conscious rabbits. J Hypertens 2016; 34:464-73; discussion 473. [PMID: 26820476 DOI: 10.1097/hjh.0000000000000811] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE High-fat diet (HFD)-induced hypertension in rabbits is neurogenic because of the central sympathoexcitatory actions of leptin. Hypothalamic melanocortin and neuropeptide Y (NPY) neurons are recognized as the major signalling pathways through which leptin exerts its central effects. In this study, we assessed the effects of specific antagonists and agonists to melanocortin and NPY receptors on HFD-induced sympathoexcitation and hypertension. METHODS Rabbits were instrumented with intracerebroventricular cannula, renal sympathetic nerve activity (RSNA) electrode, and blood pressure telemetry transmitter. RESULTS After 3 weeks HFD (13.5% fat, n = 12) conscious rabbits had higher RSNA (+3.8 nu, P = 0.02), blood pressure (+8.6 mmHg, P < 0.001) and heart rate (+15 b/min, P = 0.01), and brain-derived neurotrophic factor levels in the hypothalamus compared with rabbits fed a control diet (4.2% fat, n = 11). Intracerebroventricular administration of the melanocortin receptor antagonist SHU9119 reduced RSNA (-2.7 nu) and blood pressure (-8.5 mmHg) in HFD but not control rabbits, thus reversing 100% of the hypertension and 70% of the sympathoexcitation induced by a HFD. By contrast, blocking central NPY Y1 receptors with BVD10 increased RSNA only in HFD rabbits. Intracerebroventricular α-melanocortin stimulating hormone increased RSNA and heart rate (P < 0.001) in HFD rabbits but had no effect in control rabbits. CONCLUSION These findings suggest that obesity-induced hypertension and increased RSNA are dependent on the balance between greater activation of melanocortin signalling through melanocortin receptors and lesser activation of NPY sympathoinhibitory signalling. The amplification of the sympathoexcitatory effects of α-melanocortin stimulating hormone also indicates that the underlying mechanism is related to facilitation of leptin-melanocortin signalling, possibly involving chronic activation of brain-derived neurotrophic factor.
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Abstract
Hypertension affects over 25 % of the population with the incidence continuing to rise, due in part to the growing obesity epidemic. Chronic elevations in sympathetic nerve activity (SNA) are a hallmark of the disease and contribute to elevations in blood pressure through influences on the vasculature, kidney, and heart (i.e., neurogenic hypertension). In this regard, a number of central nervous system mechanisms and neural pathways have emerged as crucial in chronically elevating SNA. However, it is important to consider that "sympathetic signatures" are present, with differential increases in SNA to regional organs that are dependent upon the disease progression. Here, we discuss recent findings on the central nervous system mechanisms and autonomic regulatory networks involved in neurogenic hypertension, in both non-obesity- and obesity-associated hypertension, with an emphasis on angiotensin-II, salt, oxidative and endoplasmic reticulum stress, inflammation, and the adipokine leptin.
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