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Komaru Y, Bai YZ, Kreisel D, Herrlich A. Interorgan communication networks in the kidney-lung axis. Nat Rev Nephrol 2024; 20:120-136. [PMID: 37667081 DOI: 10.1038/s41581-023-00760-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2023] [Indexed: 09/06/2023]
Abstract
The homeostasis and health of an organism depend on the coordinated interaction of specialized organs, which is regulated by interorgan communication networks of circulating soluble molecules and neuronal connections. Many diseases that seemingly affect one primary organ are really multiorgan diseases, with substantial secondary remote organ complications that underlie a large part of their morbidity and mortality. Acute kidney injury (AKI) frequently occurs in critically ill patients with multiorgan failure and is associated with high mortality, particularly when it occurs together with respiratory failure. Inflammatory lung lesions in patients with kidney failure that could be distinguished from pulmonary oedema due to volume overload were first reported in the 1930s, but have been largely overlooked in clinical settings. A series of studies over the past two decades have elucidated acute and chronic kidney-lung and lung-kidney interorgan communication networks involving various circulating inflammatory cytokines and chemokines, metabolites, uraemic toxins, immune cells and neuro-immune pathways. Further investigations are warranted to understand these clinical entities of high morbidity and mortality, and to develop effective treatments.
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Affiliation(s)
- Yohei Komaru
- Department of Medicine, Division of Nephrology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Yun Zhu Bai
- Department of Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Daniel Kreisel
- Department of Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- Department of Pathology & Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Andreas Herrlich
- Department of Medicine, Division of Nephrology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA.
- VA Saint Louis Health Care System, John Cochran Division, St. Louis, MO, USA.
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2
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Brislane Á, Davenport MH, Steinback CD. The sympathetic nervous system in healthy and hypertensive pregnancies: physiology or pathology? Exp Physiol 2023; 108:1238-1244. [PMID: 36459575 PMCID: PMC10988427 DOI: 10.1113/ep089665] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 10/18/2022] [Indexed: 09/30/2023]
Abstract
NEW FINDINGS What is the topic of this review? Sympathoexcitation in both healthy and hypertensive pregnancies, and concurrent adaptations along the neurovascular cascade. What advances does it highlight? Known and plausible adaptations along the neurovascular cascade which may offset elevated MSNA in normotensive pregnancy while also highlighting knowledge gaps regarding understudied pathways. ABSTRACT The progression from conception through to the postpartum period represents an extraordinary period of physiological adaptation in the mother to support the growth and development of the fetus. Healthy, normotensive human pregnancies are associated with striking increases in both plasma volume and sympathetic nerve activity, yet normal or reduced blood pressure; it represents a unique period of apparent healthy sympathetic hyperactivity. However, how this normal blood pressure is achieved in the face of sympathoexcitation, and the mechanisms responsible for this increased activity are unclear. Importantly, sympathetic activation has been implicated in hypertensive pregnancy disorders - the leading causes of maternal-fetal morbidity and mortality in the developed world. An understudied link between pregnancy and the development of maternal hypertension may lie in the sympathetic nervous system regulation of blood pressure. This brief review presents the latest data on sympathoexcitation in both healthy and hypertensive pregnancies, and concurrent adaptations along the neurovascular cascade.
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Affiliation(s)
- Áine Brislane
- Program for Pregnancy & Postpartum HealthNeurovascular Health Lab, Faculty of Kinesiology, Sport, and RecreationWomen and Children's Health Research InstituteAlberta Diabetes InstituteUniversity of AlbertaAlbertaCanada
| | - Margie H. Davenport
- Program for Pregnancy & Postpartum HealthNeurovascular Health Lab, Faculty of Kinesiology, Sport, and RecreationWomen and Children's Health Research InstituteAlberta Diabetes InstituteUniversity of AlbertaAlbertaCanada
| | - Craig D. Steinback
- Program for Pregnancy & Postpartum HealthNeurovascular Health Lab, Faculty of Kinesiology, Sport, and RecreationWomen and Children's Health Research InstituteAlberta Diabetes InstituteUniversity of AlbertaAlbertaCanada
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3
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Slusher AL, Acevedo EO. Stress induced proinflammatory adaptations: Plausible mechanisms for the link between stress and cardiovascular disease. Front Physiol 2023; 14:1124121. [PMID: 37007994 PMCID: PMC10065149 DOI: 10.3389/fphys.2023.1124121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 03/07/2023] [Indexed: 03/19/2023] Open
Abstract
Initiating from Hans Selye’s conceptualization of stress physiology, to our present understanding of allostatic load as the cumulative burden of chronic psychological stress and life events, investigators have sought to identify the physiological mechanisms that link stress to health and disease. Of particular interest has been the link between psychological stress and cardiovascular disease (CVD), the number one cause of death in the United States. In this regard, attention has been directed toward alterations in the immune system in response to stress that lead to increased levels of systemic inflammation as a potential pathway by which stress contributes to the development of CVD. More specifically, psychological stress is an independent risk factor for CVD, and as such, mechanisms that explain the connection of stress hormones to systemic inflammation have been examined to gain a greater understanding of the etiology of CVD. Research on proinflammatory cellular mechanisms that are activated in response to psychological stress demonstrates that the ensuing low-grade inflammation mediates pathways that contribute to the development of CVD. Interestingly, physical activity, along with its direct benefits to cardiovascular health, has been shown to buffer against the harmful consequences of psychological stress by “toughening” the SAM system, HPA axis, and immune system as “cross-stressor adaptations” that maintain allostasis and prevent allostatic load. Thus, physical activity training reduces psychological stress induced proinflammation and attenuates the activation of mechanisms associated with the development of cardiovascular disease. Finally, COVID-19 associated psychological stress and its associated health risks has provided another model for examining the stress-health relationship.
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Affiliation(s)
- Aaron L. Slusher
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT, United States
- Department of Athletics, Yale University, New Haven, CT, United States
- *Correspondence: Aaron L. Slusher,
| | - Edmund O. Acevedo
- Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, United States
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4
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Nakata T, Shibasaki M, Nishimura Y, Kinoshita T, Hashizaki T, Kamijo YI, Kouda K, Umemoto Y, Tajima F. Quantification of catecholamine neurotransmitters released from cutaneous vasoconstrictor nerve endings in men with cervical spinal cord injury. Am J Physiol Regul Integr Comp Physiol 2023; 324:R345-R352. [PMID: 36693170 DOI: 10.1152/ajpregu.00063.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Control of cutaneous circulation is critically important to maintain thermoregulation, especially in individuals with cervical spinal cord injury (CSCI) who have no or less central thermoregulatory drive. However, the peripheral vasoconstrictor mechanism and capability have not been fully investigated after CSCI. Post- and presynaptic sensitivities of the cutaneous vasoconstrictor system were investigated in 8 CSCI and 7 sedentary able-bodied (AB) men using an intradermal microdialysis technique. Eight doses of norepinephrine (NE, 10-8 to 10-1 M) and five doses of tyramine (TY, 10-8, 10-5 to 10-2 M) were administered into the anterior right and left thigh, respectively. Endogenous catecholamines, noradrenaline, and dopamine, collected at the TY site, were determined by high-performance liquid chromatography with electrochemical detection. Regardless of vasoconstrictor agents, cutaneous vascular conductance decreased dose-dependently and responsiveness was similar between the groups (NE: Group P = 0.255, Dose P = 0.014; TY: Group P = 0.468, Dose P < 0.001), whereas the highest dose of each drug induced cutaneous vasodilation. Administration of TY promoted the release of noradrenaline and dopamine in both groups. Notably, the amount of noradrenaline released was similar between the groups (P = 0.819), although the concentration of dopamine was significantly greater in individuals with CSCI than in AB individuals (P = 0.004). These results suggest that both vasoconstrictor responsiveness and neural functions are maintained after CSCI, and dopamine in the skin is likely to induce cutaneous vasodilation.
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Affiliation(s)
- Tomonori Nakata
- Department of Rehabilitation Medicine, Wakayama Medical University, Wakayama, Japan
| | | | - Yukihide Nishimura
- Department of Rehabilitation Medicine, Iwate Medical University, Wakayama, Japan
| | - Tokio Kinoshita
- Department of Rehabilitation Medicine, Wakayama Medical University, Wakayama, Japan.,Division of Rehabilitation, Wakayama Medical University Hospital, Wakayama, Japan
| | - Takamasa Hashizaki
- Division of Rehabilitation, Wakayama Medical University Hospital, Wakayama, Japan
| | - Yoshi-Ichiro Kamijo
- Department of Rehabilitation Medicine, Wakayama Medical University, Wakayama, Japan.,Department of Rehabilitation Medicine, Dokkyo Medical University Saitama Medical Center, Saitama, Japan
| | - Ken Kouda
- Department of Rehabilitation Medicine, Wakayama Medical University, Wakayama, Japan
| | - Yasunori Umemoto
- Department of Rehabilitation Medicine, Wakayama Medical University, Wakayama, Japan
| | - Fumihiro Tajima
- Department of Rehabilitation Medicine, Wakayama Medical University, Wakayama, Japan
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5
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Kovac M, Vladimirovna Ippolitova T, Pozyabin S, Aliev R, Lobanova V, Drakul N, S. Rutland C. Equine Stress: Neuroendocrine Physiology and Pathophysiology. Vet Med Sci 2022. [DOI: 10.5772/intechopen.105045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
This review presents new aspects to understanding the neuroendocrine regulation of equine stress responses, and their influences on the physiological, pathophysiological, and behavioral processes. Horse management, in essence, is more frequently confirmed by external and internal stress factors, than in other domestic animals. Regardless of the nature of the stimulus, the equine stress response is an effective and highly conservative set of interconnected relationships designed to maintain physiological integrity even in the most challenging circumstances (e.g., orthopedic injuries, abdominal pain, transport, competitions, weaning, surgery, and inflammation). The equine stress response is commonly a complementary homeostatic mechanism that provides protection (not an adaptation) when the body is disturbed or threatened. It activates numerous neural and hormonal networks to optimize metabolic, cardiovascular, musculoskeletal, and immunological functions. This review looks into the various mechanisms involved in stress responses, stress-related diseases, and assessment, prevention or control, and management of these diseases and stress. Stress-related diseases can not only be identified and assessed better, given the latest research and techniques but also prevented or controlled.
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6
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Aalkjær C, Nilsson H, De Mey JGR. Sympathetic and Sensory-Motor Nerves in Peripheral Small Arteries. Physiol Rev 2020; 101:495-544. [PMID: 33270533 DOI: 10.1152/physrev.00007.2020] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Small arteries, which play important roles in controlling blood flow, blood pressure, and capillary pressure, are under nervous influence. Their innervation is predominantly sympathetic and sensory motor in nature, and while some arteries are densely innervated, others are only sparsely so. Innervation of small arteries is a key mechanism in regulating vascular resistance. In the second half of the previous century, the physiology and pharmacology of this innervation were very actively investigated. In the past 10-20 yr, the activity in this field was more limited. With this review we highlight what has been learned during recent years with respect to development of small arteries and their innervation, some aspects of excitation-release coupling, interaction between sympathetic and sensory-motor nerves, cross talk between endothelium and vascular nerves, and some aspects of their role in vascular inflammation and hypertension. We also highlight what remains to be investigated to further increase our understanding of this fundamental aspect of vascular physiology.
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Affiliation(s)
| | - Holger Nilsson
- Department Physiology, Gothenburg University, Gothenburg, Sweden
| | - Jo G R De Mey
- Deptartment Pharmacology and Personalized Medicine, Maastricht University, Maastricht, The Netherlands
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7
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Quelhas P, Baltazar G, Cairrao E. The Neurovascular Unit: Focus on the Regulation of Arterial Smooth Muscle Cells. Curr Neurovasc Res 2020; 16:502-515. [PMID: 31738142 DOI: 10.2174/1567202616666191026122642] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 09/01/2019] [Accepted: 09/20/2019] [Indexed: 02/08/2023]
Abstract
The neurovascular unit is a physiological unit present in the brain, which is constituted by elements of the nervous system (neurons and astrocytes) and the vascular system (endothelial and mural cells). This unit is responsible for the homeostasis and regulation of cerebral blood flow. There are two major types of mural cells in the brain, pericytes and smooth muscle cells. At the arterial level, smooth muscle cells are the main components that wrap around the outside of cerebral blood vessels and the major contributors to basal tone maintenance, blood pressure and blood flow distribution. They present several mechanisms by which they regulate both vasodilation and vasoconstriction of cerebral blood vessels and their regulation becomes even more important in situations of injury or pathology. In this review, we discuss the main regulatory mechanisms of brain smooth muscle cells and their contributions to the correct brain homeostasis.
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Affiliation(s)
- Patrícia Quelhas
- CICS-UBI - Centro de Investigacao em Ciencias da Saude, University of Beira Interior, 6200-506 Covilha, Portugal
| | - Graça Baltazar
- CICS-UBI - Centro de Investigacao em Ciencias da Saude, University of Beira Interior, 6200-506 Covilha, Portugal
| | - Elisa Cairrao
- CICS-UBI - Centro de Investigacao em Ciencias da Saude, University of Beira Interior, 6200-506 Covilha, Portugal
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8
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Akintunde JK, Akintola TE, Adenuga GO, Odugbemi ZA, Adetoye RO, Akintunde OG. Naringin attenuates Bisphenol-A mediated neurotoxicity in hypertensive rats by abrogation of cerebral nucleotide depletion, oxidative damage and neuroinflammation. Neurotoxicology 2020; 81:18-33. [PMID: 32810514 DOI: 10.1016/j.neuro.2020.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 08/04/2020] [Accepted: 08/06/2020] [Indexed: 02/07/2023]
Abstract
We examined whether active fruit naringin can reduce the risk of BPA-mediated neurotoxicity in L-NAME induced hypertensive rats and whether the modulation could be linked to improvement of brain NO signaling. Male albino rats were randomly distributed into eight (n = 7) groups. Group I was control animals, Group II was orally-treated with L-NAME, Group III was orally treated with 100 mg/kg BPA, Group IV was orally-treated with L-NAME +100 mg/kg BPA. Group V was orally-administered with L-NAME +80 mg/kg NAR. Group VI was orally-administered with 100 mg/kg BPA +80 mg/kg NAR. Group VII was orally-administered with L-NAME+100 mg/kg BPA +80 mg/kg NAR. Lastly, group VIII was orally-treated with 80 mg/kg NAR. The treatment lasted for 14 days. Sub-acute exposure to L-NAME and BPA induced hypertension and mediated-neuroinflammation at CA-2 and CA-4 of hippocampus cells. It was evident by increase in PDE-51 and enzymes of ATP hydrolysis (ATPase, ADPase and AMPase) with corresponding upsurge in cholinergic (AChE and BuChE), dopaminergic (MAO-A) and adenosinergic (ADA) enzymes as well as movement disorder. The hypertensive-mediated neurotoxicity was related to alteration of NO signaling and higher release of pro-inflammatory cytokines (TNF-α and IL-1β), apoptotic proteins (P53 and caspace-9) and facilitated entry of T-lymphocytes (CD43+) into CNS through blood brain barrier potentiated by antigen presenting cells. Hence, these features of BPA-mediated neurotoxicity in L-NAME induced hypertensive rats were prohibited by co-administration of NAR through production of neuro-inflammatory mediators, stabilizing neurotransmitter enzymes, normalizing NO signaling and improving brain histology.
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Affiliation(s)
- J K Akintunde
- Applied Biochemistry and Molecular Toxicology Research Group, Department of Biochemistry, College of Biosciences, Federal University of Agriculture, Abeokuta, Nigeria.
| | - T E Akintola
- Applied Biochemistry and Molecular Toxicology Research Group, Department of Biochemistry, College of Biosciences, Federal University of Agriculture, Abeokuta, Nigeria
| | - G O Adenuga
- Applied Biochemistry and Molecular Toxicology Research Group, Department of Biochemistry, College of Biosciences, Federal University of Agriculture, Abeokuta, Nigeria
| | - Z A Odugbemi
- Applied Biochemistry and Molecular Toxicology Research Group, Department of Biochemistry, College of Biosciences, Federal University of Agriculture, Abeokuta, Nigeria; Department of Physiology and Biochemistry, College of Veterinary Medicine, Federal University of Agriculture, Abeokuta, Nigeria
| | - R O Adetoye
- Applied Biochemistry and Molecular Toxicology Research Group, Department of Biochemistry, College of Biosciences, Federal University of Agriculture, Abeokuta, Nigeria
| | - O G Akintunde
- Department of Physiology and Biochemistry, College of Veterinary Medicine, Federal University of Agriculture, Abeokuta, Nigeria
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9
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Winter EM, Ireland A, Butterfield NC, Haffner-Luntzer M, Horcajada MN, Veldhuis-Vlug AG, Oei L, Colaianni G, Bonnet N. Pregnancy and lactation, a challenge for the skeleton. Endocr Connect 2020; 9:R143-R157. [PMID: 32438342 PMCID: PMC7354730 DOI: 10.1530/ec-20-0055] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 05/12/2020] [Indexed: 12/19/2022]
Abstract
In this review we discuss skeletal adaptations to the demanding situation of pregnancy and lactation. Calcium demands are increased during pregnancy and lactation, and this is effectuated by a complex series of hormonal changes. The changes in bone structure at the tissue and whole bone level observed during pregnancy and lactation appear to largely recover over time. The magnitude of the changes observed during lactation may relate to the volume and duration of breastfeeding and return to regular menses. Studies examining long-term consequences of pregnancy and lactation suggest that there are small, site-specific benefits to bone density and that bone geometry may also be affected. Pregnancy- and lactation-induced osteoporosis (PLO) is a rare disease for which the pathophysiological mechanism is as yet incompletely known; here, we discuss and speculate on the possible roles of genetics, oxytocin, sympathetic tone and bone marrow fat. Finally, we discuss fracture healing during pregnancy and lactation and the effects of estrogen on this process.
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Affiliation(s)
- E M Winter
- Leiden University Medical Center, Department of Internal Medicine, Division of Endocrinology, Center for Bone Quality, Leiden, the Netherlands
- Correspondence should be addressed to E M Winter:
| | - A Ireland
- Musculoskeletal Science and Sports Medicine Research Centre, Department of Life Sciences, Manchester Metropolitan University, Manchester, United Kingdom
| | - N C Butterfield
- Molecular Endocrinology Laboratory, Department of Metabolism, Digestion and Reproduction, Imperial College London, Commonwealth Building, DuCane Road, London, United Kingdom
| | - M Haffner-Luntzer
- Institute of Orthopaedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
| | - M-N Horcajada
- Nestlé Research, Department of Musculoskeletal Health, Innovation EPFL Park, Lausanne, Switzerland.
| | - A G Veldhuis-Vlug
- Leiden University Medical Center, Department of Internal Medicine, Division of Endocrinology, Center for Bone Quality, Leiden, the Netherlands
- Jan van Goyen Medical Center, Department of Internal Medicine, Amsterdam, the Netherlands
| | - L Oei
- Department of Internal Medicine, Erasmus MC, University Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands
| | - G Colaianni
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - N Bonnet
- Nestlé Research, Department of Musculoskeletal Health, Innovation EPFL Park, Lausanne, Switzerland.
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10
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Stuckless TJR, Vermeulen TD, Brown CV, Boulet LM, Shafer BM, Wakeham DJ, Steinback CD, Ayas NT, Floras JS, Foster GE. Acute intermittent hypercapnic hypoxia and sympathetic neurovascular transduction in men. J Physiol 2020; 598:473-487. [PMID: 31805605 DOI: 10.1113/jp278941] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 12/03/2019] [Indexed: 01/02/2023] Open
Abstract
KEY POINTS Intermittent hypoxia leads to long-lasting increases in muscle sympathetic nerve activity and blood pressure, contributing to increased risk for hypertension in obstructive sleep apnoea patients. We determined whether augmented vascular responses to increasing sympathetic vasomotor outflow, termed sympathetic neurovascular transduction (sNVT), accompanied changes in blood pressure following acute intermittent hypercapnic hypoxia in men. Lower body negative pressure was utilized to induce a range of sympathetic vasoconstrictor firing while measuring beat-by-beat blood pressure and forearm vascular conductance. IH reduced vascular shear stress and steepened the relationship between diastolic blood pressure and sympathetic discharge frequency, suggesting greater systemic sNVT. Our results indicate that recurring cycles of acute intermittent hypercapnic hypoxia characteristic of obstructive sleep apnoea could promote hypertension by increasing sNVT. ABSTRACT Acute intermittent hypercapnic hypoxia (IH) induces long-lasting elevations in sympathetic vasomotor outflow and blood pressure in healthy humans. It is unknown whether IH alters sympathetic neurovascular transduction (sNVT), measured as the relationship between sympathetic vasomotor outflow and either forearm vascular conductance (FVC; regional sNVT) or diastolic blood pressure (systemic sNVT). We tested the hypothesis that IH augments sNVT by exposing healthy males to 40 consecutive 1 min breathing cycles, each comprising 40 s of hypercapnic hypoxia ( P ETC O 2 : +4 ± 3 mmHg above baseline; P ET O 2 : 48 ± 3 mmHg) and 20 s of normoxia (n = 9), or a 40 min air-breathing control (n = 7). Before and after the intervention, lower body negative pressure (LBNP; 3 min at -15, -30 and -45 mmHg) was applied to elicit reflex increases in muscle sympathetic nerve activity (MSNA, fibular microneurography) when clamping end-tidal gases at baseline levels. Ventilation, arterial pressure [systolic blood pressure, diastolic blood pressure, mean arterial pressure (MAP)], brachial artery blood flow ( Q ̇ BA ), FVC ( Q ̇ BA /MAP) and MSNA burst frequency were measured continuously. Following IH, but not control, ventilation [5 L min-1 ; 95% confidence interval (CI) = 1-9] and MAP (5 mmHg; 95% CI = 1-9) were increased, whereas FVC (-0.2 mL min-1 mmHg-1 ; 95% CI = -0.0 to -0.4) and mean shear rate (-21.9 s-1 ; 95% CI = -5.8 to -38.0; all P < 0.05) were reduced. Systemic sNVT was increased following IH (0.25 mmHg burst-1 min-1 ; 95% CI = 0.01-0.49; P < 0.05), whereas changes in regional forearm sNVT were similar between IH and sham. Reductions in vessel wall shear stress and, consequently, nitric oxide production may contribute to heightened systemic sNVT and provide a potential neurovascular mechanism for elevated blood pressure in obstructive sleep apnoea.
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Affiliation(s)
- Troy J R Stuckless
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, Canada
| | - Tyler D Vermeulen
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, Canada
| | - Courtney V Brown
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, Canada
| | - Lindsey M Boulet
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, Canada
| | - Brooke M Shafer
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, Canada
| | - Denis J Wakeham
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | - Craig D Steinback
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, AB, Canada
| | - Najib T Ayas
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - John S Floras
- University Health Network and Mount Sinai Hospital Division of Cardiology, Toronto, ON, Canada.,Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Glen E Foster
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, Canada
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11
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Wu Y, He H, Cheng Z, Bai Y, Ma X. The Role of Neuropeptide Y and Peptide YY in the Development of Obesity via Gut-brain Axis. Curr Protein Pept Sci 2019; 20:750-758. [PMID: 30678628 DOI: 10.2174/1389203720666190125105401] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 12/30/2018] [Accepted: 01/11/2019] [Indexed: 12/15/2022]
Abstract
Obesity is one of the main challenges of public health in the 21st century. Obesity can induce a series of chronic metabolic diseases, such as diabetes, dyslipidemia, hypertension and nonalcoholic fatty liver, which seriously affect human health. Gut-brain axis, the two-direction pathway formed between enteric nervous system and central nervous system, plays a vital role in the occurrence and development of obesity. Gastrointestinal signals are projected through the gut-brain axis to nervous system, and respond to various gastrointestinal stimulation. The central nervous system regulates visceral activity through the gut-brain axis. Brain-gut peptides have important regulatory roles in the gut-brain axis. The brain-gut peptides of the gastrointestinal system and the nervous system regulate the gastrointestinal movement, feeling, secretion, absorption and other complex functions through endocrine, neurosecretion and paracrine to secrete peptides. Both neuropeptide Y and peptide YY belong to the pancreatic polypeptide family and are important brain-gut peptides. Neuropeptide Y and peptide YY have functions that are closely related to appetite regulation and obesity formation. This review describes the role of the gutbrain axis in regulating appetite and maintaining energy balance, and the functions of brain-gut peptides neuropeptide Y and peptide YY in obesity. The relationship between NPY and PYY and the interaction between the NPY-PYY signaling with the gut microbiota are also described in this review.
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Affiliation(s)
- Yi Wu
- State Key Lab of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Hengxun He
- State Key Lab of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Zhibin Cheng
- College of Animal Science and Technology, Yunnan Agricultural University, Kunming, Yunan 650201, China
| | - Yueyu Bai
- Animal Health Supervision of Henan province, Breeding Animal Genetic Performance Measurement Center of Henan province, Zhengzhou, Henan 450008, China.,Henan Institute of Science and Technology, Xinxiang, Henan 453003, China
| | - Xi Ma
- State Key Lab of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
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12
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Medow MS, Guber K, Chokshi S, Terilli C, Visintainer P, Stewart JM. The Benefits of Oral Rehydration on Orthostatic Intolerance in Children with Postural Tachycardia Syndrome. J Pediatr 2019; 214:96-102. [PMID: 31405524 PMCID: PMC6815702 DOI: 10.1016/j.jpeds.2019.07.041] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/11/2019] [Accepted: 07/15/2019] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To evaluate whether equal volumes of oral rehydration solution (ORS) or intravenous (IV) saline provide similar improvements in cardiovascular status during controlled orthostatic challenge when administered to subjects with postural tachycardia syndrome (POTS) with orthostatic intolerance. STUDY DESIGN We studied the neurovascular response to fluid loading during orthostatic stress using lower body negative pressure (LBNP) in 10 subjects with POTS with orthostatic intolerance and 15 controls, and on subsequent days before and 1 hour after IV saline infusion or ingestion of ORS. RESULTS Subjects with POTS exhibited reduced tolerance to LBNP (P < .0001) compared with controls (Orthostatic Index of 35 715 ± 3469 vs 93 980 ± 7977, respectively). In POTS, following ORS but not saline infusion, cerebral blood flow velocity (CBFv) was significantly higher than that with no treatment, at -45 mm Hg (P < .0005). Although fluid loading did not confer any advantage in controls, subjects with POTS experienced a significant improvement in orthostatic tolerance following both saline infusion (100 ± 9.7 vs 134.5 ± 17.4; P < .05) and ORS (100 ± 9.7 vs 155.6 ± 15.7; P < .001) when evaluated by normalized orthostatic index (P < .001, compared with untreated baseline). CONCLUSIONS Maintenance of CBFv may have resulted in the improved short-term orthostatic tolerance exhibited by the subjects with POTS following ORS administration. ORS is a convenient, safe, and effective therapy for short-term relief of orthostatic intolerance.
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Affiliation(s)
- Marvin S Medow
- Department of Pediatrics, New York Medical College, Valhalla, NY; Department of Physiology, New York Medical College, Valhalla, NY.
| | | | | | - Courtney Terilli
- Department of Pediatrics, New York Medical College, Valhalla, NY
| | - Paul Visintainer
- Department of Epidemiology and Biostatistics, Baystate Medical Center, University of Massachusetts School of Medicine, Worcester, MA
| | - Julian M Stewart
- Department of Pediatrics, New York Medical College, Valhalla, NY; Department of Physiology, New York Medical College, Valhalla, NY
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13
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Reyes LM, Usselman CW, Davenport MH, Steinback CD. Sympathetic Nervous System Regulation in Human Normotensive and Hypertensive Pregnancies. Hypertension 2018. [DOI: 10.1161/hypertensionaha.117.10766] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Laura M. Reyes
- From the Program for Pregnancy and Postpartum Health, Faculty of Kinesiology, Sport and Recreation, Women and Children’s Health Research Institute (L.M.R., C.W.U., M.H.D., C.D.S.) and Alberta Diabetes Institute (M.H.D.), University of Alberta, Edmonton, Canada
| | - Charlotte W. Usselman
- From the Program for Pregnancy and Postpartum Health, Faculty of Kinesiology, Sport and Recreation, Women and Children’s Health Research Institute (L.M.R., C.W.U., M.H.D., C.D.S.) and Alberta Diabetes Institute (M.H.D.), University of Alberta, Edmonton, Canada
| | - Margie H. Davenport
- From the Program for Pregnancy and Postpartum Health, Faculty of Kinesiology, Sport and Recreation, Women and Children’s Health Research Institute (L.M.R., C.W.U., M.H.D., C.D.S.) and Alberta Diabetes Institute (M.H.D.), University of Alberta, Edmonton, Canada
| | - Craig D. Steinback
- From the Program for Pregnancy and Postpartum Health, Faculty of Kinesiology, Sport and Recreation, Women and Children’s Health Research Institute (L.M.R., C.W.U., M.H.D., C.D.S.) and Alberta Diabetes Institute (M.H.D.), University of Alberta, Edmonton, Canada
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14
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Ramirez-Lee MA, Aguirre-Bañuelos P, Martinez-Cuevas PP, Espinosa-Tanguma R, Chi-Ahumada E, Martinez-Castañon GA, Gonzalez C. Evaluation of cardiovascular responses to silver nanoparticles (AgNPs) in spontaneously hypertensive rats. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2017; 14:385-395. [PMID: 29175596 DOI: 10.1016/j.nano.2017.11.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 10/02/2017] [Accepted: 11/15/2017] [Indexed: 12/31/2022]
Abstract
Silver nanoparticles (AgNPs) are used in the medical, pharmaceutical and food industry. Adverse effects and toxicity induced by AgNPs upon cardiac function related to nitric oxide (NO) and oxidative stress (OS) are described. AgNPs-toxicity may be influenced by cardiovascular pathologies such as hypertension. However, the molecules involved under pathophysiological conditions are not well studied. The aim of this work was to evaluate perfusion pressure (PP) and left ventricle pressure (LVP) as physiological parameters of cardiovascular function in response to AgNPs, using isolated perfused hearts from spontaneously hypertensive rats (SHR), and identify the role of NO and OS. The results suggest that AgNPs reduced NO derived from endothelial/inducible NO-synthase and increased OS, leading to increased and sustained vasoconstriction and myocardial contractility. Additionally, the hypertension condition alters phenylephrine (Phe) and acetylcholine (ACh) classic effects. These data suggest that hypertension intensified AgNPs-cardiotoxicity. Nevertheless, the precise mechanism of action is still under elucidation.
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Affiliation(s)
| | - Patricia Aguirre-Bañuelos
- Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, San Luis Potosi, S.L.P., Mexico
| | | | | | - Erika Chi-Ahumada
- Facultad de Medicina, Universidad Autonoma de San Luis Potosi, San Luis, S.L.P., Mexico
| | | | - Carmen Gonzalez
- Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, San Luis Potosi, S.L.P., Mexico.
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15
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Wenner MM, Sebzda KN, Kuczmarski AV, Pohlig RT, Edwards DG. ET B receptor contribution to vascular dysfunction in postmenopausal women. Am J Physiol Regul Integr Comp Physiol 2017; 313:R51-R57. [PMID: 28438762 DOI: 10.1152/ajpregu.00410.2016] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 03/27/2017] [Accepted: 04/20/2017] [Indexed: 01/05/2023]
Abstract
Endothelin-1 (ET-1) contributes to age-related endothelial dysfunction in men via the ETA receptor. However, there are sex differences in the ET-1 system, and ETB receptors are modulated by sex hormones. The purpose of this study was to test the hypothesis that ETB receptors contribute to impaired vasodilatory function in postmenopausal women (PMW). We measured flow-mediated dilation (FMD) using ultrasound, and cutaneous nitric oxide-mediated vasodilation during local heating (42°C) via laser Doppler flowmetry in 18 young women (YW; 22 ± 1 yr) and 16 PMW (56 ± 1 yr). Cutaneous microdialysis perfusions of lactated Ringer (control), an ETB receptor antagonist (BQ-788, 300 nM), and an ETA receptor antagonist (BQ-123, 500 nM), were done through separate fibers, followed by perfusions of sodium nitroprusside (28 mM) and local heating to 43°C (max). Cutaneous vascular conductance (CVC) was calculated as cutaneous blood flow/mean arterial pressure and expressed as a percent of maximal dilation. FMD (YW: 7.5 ± 0.5 vs. PMW: 5.6 ± 0.6%) and cutaneous vasodilation (YW: 93 ± 2 vs. PMW: 83 ± 4%CVCmax) were lower in PMW (both P < 0.05). Blockade of ETB receptors decreased cutaneous vasodilation in YW (87 ± 2%CVCmax; P < 0.05 vs. control) but increased vasodilation in PMW (93 ± 1%CVCmax; P < 0.05 vs. control). ETA receptor blockade had minimal effect in YW (92 ± 1%CVCmax) but increased cutaneous vasodilation in PMW (91 ± 2%CVCmax; P < 0.05 vs. control). In conclusion, ETB receptors mediate vasodilation in YW, but this effect is lost after menopause. Impaired vasodilatory function in PMW is due in part to a loss of ETB-mediated dilation.
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Affiliation(s)
- Megan M Wenner
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware; and
| | - Kelly N Sebzda
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware; and
| | - Andrew V Kuczmarski
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware; and
| | - Ryan T Pohlig
- Biostatistics Core Facility, College of Health Sciences, University of Delaware, Newark, Delaware
| | - David G Edwards
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware; and
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16
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Medow MS, Merchant S, Suggs M, Terilli C, O’Donnell-Smith B, Stewart JM. Postural Heart Rate Changes in Young Patients With Vasovagal Syncope. Pediatrics 2017; 139:peds.2016-3189. [PMID: 28351846 PMCID: PMC5369676 DOI: 10.1542/peds.2016-3189] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/24/2017] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Recurrent postural vasovagal syncope (VVS) is caused by transient cerebral hypoperfusion from episodic hypotension and bradycardia; diagnosis is made by medical history. VVS contrasts with postural tachycardia syndrome (POTS), defined by chronic daily symptoms of orthostatic intolerance with excessive upright tachycardia without hypotension. POTS has recently been conflated with VVS when excessive tachycardia is succeeded by hypotension during tilt testing. We hypothesize that excessive tachycardia preceding hypotension and bradycardia is part of the vasovagal response during tilt testing of patients with VVS. METHODS We prospectively performed head-up tilt (HUT) testing on patients with recurrent VVS (n = 47, 17.9 ± 1.1 y), who fainted at least 3 times within the last year, and control subjects (n = 15, 17.1 ± 1.0 y), from age and BMI-matched volunteers and measured blood pressure, heart rate (HR), cardiac output, total peripheral resistance, and end tidal carbon dioxide. RESULTS Baseline parameters were the same in both groups. HR (supine versus 5 and 10 minutes HUT) significantly increased in control (65 ± 2.6 vs 83 ± 3.6 vs 85 ± 3.7, P < .001) and patients with VVS (69 ± 1.6 vs 103 ± 2.3 vs 109 ± 2.4, P < .001). HUT in controls maximally increased HR by 20.3 ± 2.9 beats per minute; the increase in patients with VVS of 39.8 ± 2.1 beats per minute was significantly greater (P < .001). An increase in HR of ≥40 beats per minute by 5 and 10 minutes or before faint with HUT, occurred in 26% and 44% of patients with VVS, respectively, but not in controls. CONCLUSIONS Orthostasis in VVS is accompanied by large increases in HR that should not be construed as POTS.
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Affiliation(s)
- Marvin S. Medow
- Departments of Pediatrics, and,Physiology, New York Medical College, Valhalla, New York
| | | | | | | | | | - Julian M. Stewart
- Departments of Pediatrics, and,Physiology, New York Medical College, Valhalla, New York
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17
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Dănilă MD, Privistirescu A, Duicu OM, Rațiu CD, Angoulvant D, Muntean DM, Sturza A. The effect of purinergic signaling via the P 2Y 11 receptor on vascular function in a rat model of acute inflammation. Mol Cell Biochem 2017; 431:37-44. [PMID: 28213772 DOI: 10.1007/s11010-017-2973-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 02/02/2017] [Indexed: 01/22/2023]
Abstract
There is a growing body of evidence pointing to the role of purinergic signaling in the development and progression of various conditions that have inflammation as a common pathogenetic denominator. The aim of the present study was to assess the involvement of P2Y11 purinergic receptors in the regulation of vascular function in aortic segments obtained using an experimental model of acute inflammation, the lipopolysaccharide (LPS, 8 mg/kg, i.p)-treated rats. Twelve hours after LPS administration, thoracic aortas were isolated and used for studies of vascular reactivity in the organ bath and for the measurement of reactive oxygen species (ROS) generation, respectively. LPS treatment significantly increased contractility to phenylephrine and attenuated the endothelium-dependent relaxation of the vascular segments in response to acetylcholine; an increased production of hydrogen peroxide (H2O2) was also recorded. The P2Y11 activator, NF546, decreased the LPS-induced aortic H2O2 release and partially normalized the vasomotor function, namely reduced contractility and improved relaxation. The effect was abolished by co-treatment with the P2Y11 inhibitor, NF340, and also after endothelium denudation. Importantly, NF546 did not elicit an antioxidant effect by acting as a H2O2 scavenger, suggesting that the beneficial outcome of this treatment on the vasculature is the consequence of P2Y11 stimulation. In conclusion, purinergic P2Y11 receptors stimulation improves vascular function and mitigates oxidative stress in the setting of acute systemic inflammation, revealing salutary effects and therapeutic potential in pathologies associated with endothelial dysfunction.
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Affiliation(s)
- Maria D Dănilă
- Department of Functional Sciences - Pathophysiology, "Victor Babeş" University of Medicine and Pharmacy Timișoara, 2 Eftimie Murgu Sq., 300041, Timişoara, Romania.,Center for Translational Research and Systems Medicine, "Victor Babeş" University of Medicine and Pharmacy Timișoara, 2 Eftimie Murgu Sq., 300041, Timişoara, Romania
| | - Andreea Privistirescu
- Department of Functional Sciences - Pathophysiology, "Victor Babeş" University of Medicine and Pharmacy Timișoara, 2 Eftimie Murgu Sq., 300041, Timişoara, Romania
| | - Oana M Duicu
- Department of Functional Sciences - Pathophysiology, "Victor Babeş" University of Medicine and Pharmacy Timișoara, 2 Eftimie Murgu Sq., 300041, Timişoara, Romania.,Center for Translational Research and Systems Medicine, "Victor Babeş" University of Medicine and Pharmacy Timișoara, 2 Eftimie Murgu Sq., 300041, Timişoara, Romania
| | - Corina D Rațiu
- Department of Functional Sciences - Pathophysiology, "Victor Babeş" University of Medicine and Pharmacy Timișoara, 2 Eftimie Murgu Sq., 300041, Timişoara, Romania
| | - Denis Angoulvant
- EA 4245 Cellules Dendritiques, Immunomodulation et Greffes, Université François-Rabelais de Tours, 37032, Tours, France.,Service de Cardiologie, Hôpital Trousseau, Centre Hospitalier Régional Universitaire de Tours, 37044, Tours, France
| | - Danina M Muntean
- Department of Functional Sciences - Pathophysiology, "Victor Babeş" University of Medicine and Pharmacy Timișoara, 2 Eftimie Murgu Sq., 300041, Timişoara, Romania. .,Center for Translational Research and Systems Medicine, "Victor Babeş" University of Medicine and Pharmacy Timișoara, 2 Eftimie Murgu Sq., 300041, Timişoara, Romania.
| | - Adrian Sturza
- Department of Functional Sciences - Pathophysiology, "Victor Babeş" University of Medicine and Pharmacy Timișoara, 2 Eftimie Murgu Sq., 300041, Timişoara, Romania.,Center for Translational Research and Systems Medicine, "Victor Babeş" University of Medicine and Pharmacy Timișoara, 2 Eftimie Murgu Sq., 300041, Timişoara, Romania
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18
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Sympathetic Hyperactivity, Increased Tyrosine Hydroxylase and Exaggerated Corpus Cavernosum Relaxations Associated with Oxidative Stress Plays a Major Role in the Penis Dysfunction in Townes Sickle Cell Mouse. PLoS One 2016; 11:e0166291. [PMID: 27935981 PMCID: PMC5147818 DOI: 10.1371/journal.pone.0166291] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 10/26/2016] [Indexed: 11/30/2022] Open
Abstract
Background Sickle cell disease patients display priapism that may progress to erectile dysfunction. However, little is known about the pathophysiological alterations of corpus cavernosum in sickle cell disease. Objective Thus, this study aimed to evaluate the functional and molecular alterations of sympathetic machinery and nitric oxide—cyclic guanosine monophosphate signaling pathway in Townes transgenic sickle cell disease mice. Methods Concentration–response curves to contractile (phenylephrine) and relaxant agents (acetylcholine and sodium nitroprusside) were obtained in corpus cavernosum strips from sickle and C57BL/6 (control) mice. Neurogenic contractions and nitrergic relaxations were obtained using electrical-field stimulation. Measurements of endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), phosphodiesterase-5 (PDE5) and α1A-, α1B- and α1D-adrenoceptor mRNA expressions and reactive-oxygen species were performed. Tyrosine hydroxylase phosphorylated at Ser-31 and total tyrosine hydroxylase protein expressions in cavernosal tissues were also measured. Results The neurogenic contractions were higher in the sickle cell disease group, in association with elevated tyrosine hydroxylase phosphorylated at Ser-31 and total tyrosine hydroxylase protein expression, as well as increased tyrosine hydroxylase mRNA expression. Likewise, phenylephrine-induced contractions were greater in the sickle mice, whereas α1A-, α1B- and α1D-adrenoceptor mRNA expression remained unchanged. Cavernosal relaxations to acetylcholine, sodium nitroprusside and EFS were higher in sickle mice, accompanied by decreased eNOS and nNOS, along with lower PDE5 mRNA expression. An increase of about 40% in reactive-oxygen species generation in corpus cavernosum from sickle mice was also detected. Conclusion Our study shows that decreased nitric oxide bioavailability in erectile tissue due to increased oxidative stress leads to both sympathetic hyperactivity and dysregulation of nitric oxide signaling in corpus cavernosum from Townes sickle mice.
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19
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Gutkin M, Stewart JM. Orthostatic Circulatory Disorders: From Nosology to Nuts and Bolts. Am J Hypertens 2016; 29:1009-19. [PMID: 27037712 PMCID: PMC4978226 DOI: 10.1093/ajh/hpw023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Revised: 11/27/2015] [Accepted: 02/12/2016] [Indexed: 12/17/2022] Open
Abstract
When patients complain of altered consciousness or discomfort in the upright posture, either relieved by recumbency or culminating in syncope, physicians may find themselves baffled. There is a wide variety of disorders that cause abnormal regulation of blood pressure and pulse rate in the upright posture. The aim of this focused review is 3-fold. First, to offer a classification (nosology) of these disorders; second, to illuminate the mechanisms that underlie them; and third, to assist the physician in the practical aspects of diagnosis of adult orthostatic hypotension, by extending clinical skills with readily available office technology.
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Affiliation(s)
- Michael Gutkin
- Hypertension Section, Saint Barnabas Medical Center, Livingston, New Jersey, USA;
| | - Julian M Stewart
- Center for Hypotension, New York Medical College, Valhalla, New Jersey, USA
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20
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Simkins TJ, Fried D, Parikh K, Galligan JJ, Goudreau JL, Lookingland KJ, Kaplan BLF. Reduced Noradrenergic Signaling in the Spleen Capsule in the Absence of CB 1 and CB 2 Cannabinoid Receptors. J Neuroimmune Pharmacol 2016; 11:669-679. [PMID: 27287619 DOI: 10.1007/s11481-016-9689-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 06/02/2016] [Indexed: 11/27/2022]
Abstract
The spleen is a visceral organ that contracts during hypoxia to expel erythrocytes and immune cells into the circulation. Spleen contraction is under the control of noradrenergic sympathetic innervation. The activity of noradrenergic neurons terminating in the spleen capsule is regulated by α2-adrenergic receptors (AR). Interactions between endogenous cannabinoid signaling and noradrenergic signaling in other organ systems suggest endocannabinoids might also regulate spleen contraction. Spleens from mice congenitally lacking both CB1 and CB2 cannabinoid receptors (Cnr1 -/- /Cnr2 -/- mice) were used to explore the role of endocannabinoids in spleen contraction. Spleen contraction in response to exogenous norepinephrine (NE) was found to be significantly lower in Cnr1 -/- /Cnr2 -/- mouse spleens, likely due to decreased expression of capsular α1AR. The majority of splenic Cnr1 mRNA expression is by cells of the spleen capsule, suggestive of post-synaptic CB1 receptor signaling. Thus, these studies demonstrate a role for CB1 and/or CB2 in noradrenergic splenic contraction.
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Affiliation(s)
- Tyrell J Simkins
- Neuroscience Program, Michigan State University, East Lansing, MI, USA
- Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA
| | - David Fried
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Kevin Parikh
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - James J Galligan
- Neuroscience Program, Michigan State University, East Lansing, MI, USA
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - John L Goudreau
- Neuroscience Program, Michigan State University, East Lansing, MI, USA
- Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Keith J Lookingland
- Neuroscience Program, Michigan State University, East Lansing, MI, USA
- Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Barbara L F Kaplan
- Neuroscience Program, Michigan State University, East Lansing, MI, USA.
- Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA.
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA.
- Department of Basic Sciences, Mississippi State University, PO Box 6100, Mississippi State, MS, 39762, USA.
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21
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Sousa JB, Vieira-Rocha MS, Arribas SM, González MC, Fresco P, Diniz C. Endothelial and Neuronal Nitric Oxide Activate Distinct Pathways on Sympathetic Neurotransmission in Rat Tail and Mesenteric Arteries. PLoS One 2015; 10:e0129224. [PMID: 26075386 PMCID: PMC4468141 DOI: 10.1371/journal.pone.0129224] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 05/06/2015] [Indexed: 02/07/2023] Open
Abstract
Nitric oxide (NO) seems to contribute to vascular homeostasis regulating neurotransmission. This work aimed at assessing the influence of NO from different sources and respective intracellular pathways on sympathetic neurotransmission, in two vascular beds. Electrically-evoked [3H]-noradrenaline release was assessed in rat mesenteric and tail arteries in the presence of NO donors or endothelial/neuronal nitric oxide synthase (NOS) inhibitors. The influence of NO on adenosine-mediated effects was also studied using selective antagonists for adenosine receptors subtypes. Location of neuronal NOS (nNOS) was investigated by immunohistochemistry (with specific antibodies for nNOS and for Schwann cells) and Confocal Microscopy. Results indicated that: 1) in mesenteric arteries, noradrenaline release was reduced by NO donors and it was increased by nNOS inhibitors; the effect of NO donors was only abolished by the adenosine A1 receptors antagonist; 2) in tail arteries, noradrenaline release was increased by NO donors and it was reduced by eNOS inhibitors; adenosine receptors antagonists were devoid of effect; 3) confocal microscopy showed nNOS staining in adventitial cells, some co-localized with Schwann cells. nNOS staining and its co-localization with Schwann cells were significantly lower in tail compared to mesenteric arteries. In conclusion, in mesenteric arteries, nNOS, mainly located in Schwann cells, seems to be the main source of NO influencing perivascular sympathetic neurotransmission with an inhibitory effect, mediated by adenosine A1 receptors activation. Instead, in tail arteries endothelial NO seems to play a more relevant role and has a facilitatory effect, independent of adenosine receptors activation.
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Affiliation(s)
- Joana Beatriz Sousa
- Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
- LAQV/REQUIMTE, University of Porto, Porto, Portugal
- * E-mail:
| | - Maria Sofia Vieira-Rocha
- Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
- LAQV/REQUIMTE, University of Porto, Porto, Portugal
| | - Silvia M. Arribas
- Department of Physiology, Faculty of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
| | - Maria Carmen González
- Department of Physiology, Faculty of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
| | - Paula Fresco
- Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Carmen Diniz
- Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
- LAQV/REQUIMTE, University of Porto, Porto, Portugal
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22
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Silva FH, Lanaro C, Leiria LO, Rodrigues RL, Davel AP, Claudino MA, Toque HA, Antunes E. Oxidative stress associated with middle aging leads to sympathetic hyperactivity and downregulation of soluble guanylyl cyclase in corpus cavernosum. Am J Physiol Heart Circ Physiol 2014; 307:H1393-400. [DOI: 10.1152/ajpheart.00708.2013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Impairment of nitric oxide (NO)-mediated cavernosal relaxations in middle age contributes to erectile dysfunction. However, little information is available about the alterations of sympathetic neurotransmission and contraction in erectile tissue at middle age. This study aimed to evaluate the alterations of the contractile machinery associated with tyrosine hydroxylase (TH) in rat corpus cavernosum (RCC) at middle age, focusing on the role of superoxide anion. Male Wistar young (3.5-mo) and middle-aged (10-mo) rats were used. Electrical-field stimulation (EFS)- and phenylephrine-induced contractions were obtained in RCC strips. Levels of reactive-oxygen species (ROS) and TH mRNA expression, as well as protein expressions for α1/β1-subunits of soluble guanylyl cyclase (sGC), in RCC were evaluated. The neurogenic contractile responses elicited by EFS (4–32 Hz) were greater in RCC from the middle-aged group that was accompanied by elevated TH mRNA expression ( P < 0.01). Phenylephrine-induced contractions were also greater in the middle-aged group. A 62% increase in ROS generation in RCC from middle-aged rats was observed. The mRNA expression for the α1A-adrenoceptor remained unchanged among groups. Protein levels of α1/β1-sGC subunits were decreased in RCC from the middle-aged compared with young group. The NADPH oxidase inhibitor apocynin (85 mg·rat−1·day−1, 4 wk) fully restored the enhanced ROS production, TH mRNA expressions, and α1/β1-subunit sGC expression, indicating that excess of superoxide anion plays a major role in the sympathetic hyperactivity and hypercontractility in erectile tissue at middle age. Reduction of oxidative stress by dietary antioxidants may be an interesting approach to treat erectile dysfunction in aging population.
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Affiliation(s)
- Fábio H. Silva
- Department of Pharmacology, Faculty of Medical Sciences and Department of Anatomy, Cellular Biology, Physiology and Biophysics, Institute of Biology, University of Campinas, Campinas, São Paulo, Brazil; and
| | - Carolina Lanaro
- Department of Pharmacology, Faculty of Medical Sciences and Department of Anatomy, Cellular Biology, Physiology and Biophysics, Institute of Biology, University of Campinas, Campinas, São Paulo, Brazil; and
| | - Luiz Osório Leiria
- Department of Pharmacology, Faculty of Medical Sciences and Department of Anatomy, Cellular Biology, Physiology and Biophysics, Institute of Biology, University of Campinas, Campinas, São Paulo, Brazil; and
| | - Renata Lopes Rodrigues
- Department of Pharmacology, Faculty of Medical Sciences and Department of Anatomy, Cellular Biology, Physiology and Biophysics, Institute of Biology, University of Campinas, Campinas, São Paulo, Brazil; and
| | - Ana Paula Davel
- Department of Pharmacology, Faculty of Medical Sciences and Department of Anatomy, Cellular Biology, Physiology and Biophysics, Institute of Biology, University of Campinas, Campinas, São Paulo, Brazil; and
| | - Mário A. Claudino
- Department of Pharmacology, Faculty of Medical Sciences and Department of Anatomy, Cellular Biology, Physiology and Biophysics, Institute of Biology, University of Campinas, Campinas, São Paulo, Brazil; and
| | - Haroldo A. Toque
- Department of Pharmacology and Toxicology, Georgia Health Sciences University, Augusta, Georgia
| | - Edson Antunes
- Department of Pharmacology, Faculty of Medical Sciences and Department of Anatomy, Cellular Biology, Physiology and Biophysics, Institute of Biology, University of Campinas, Campinas, São Paulo, Brazil; and
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23
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Martínez AC, Hernández M, Novella S, Martínez MP, Pagán RM, Hermenegildo C, García-Sacristán A, Prieto D, Benedito S. Diminished neurogenic femoral artery vasoconstrictor response in a Zucker obese rat model: differential regulation of NOS and COX derivatives. PLoS One 2014; 9:e106372. [PMID: 25216050 PMCID: PMC4162543 DOI: 10.1371/journal.pone.0106372] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 08/03/2014] [Indexed: 01/21/2023] Open
Abstract
Objective Peripheral arterial disease is one of the macrovascular complications of type 2 diabetes mellitus. This study addresses femoral artery regulation in a prediabetic model of obese Zucker rats (OZR) by examining cross-talk between endothelial and neural factors. Methods and Results Arterial preparations from lean (LZR) and OZR were subjected to electrical field stimulation (EFS) on basal tone. Nitric oxide synthase (NOS) and cyclooxygenase (COX) isoform expression patterns were determined by immunohistochemical labelling and Western blotting. Results indicate significantly reduced noradrenergic contractions in preparations from OZR compared with those of LZR. Functional inhibition of endothelial NOS (eNOS) indicated a predominant role of this isoform in LZR and its modified activity in OZR. Neural (nNOS) and inducible NOS (iNOS) were activated and their expression was higher in femoral arteries from OZR. Neurotransmission modulated by large-conductance Ca2+-activated (BKCa) or voltage-dependent (KV) K+ channels did not seem compromised in the obese animals. Endothelial COX-1 and COX-2 were expressed in LZR and an additional adventitial location of COX-2 was also observed in OZR, explaining the higher COX-2 protein levels detected in this group. Prostanoids derived from both isoforms helped maintain vasoconstriction in LZR while in OZR only COX-2 was active. Superoxide anion inhibition reduced contractions in endothelium-intact arteries from OZR. Conclusions Endothelial dysfunction led to reduced neurogenic vasoconstriction in femoral arteries from OZR. In a setting of obesity, NO-dependent nNOS and iNOS dilation activity could be an alternative mechanism to offset COX-2- and reactive oxygen species-mediated vasoconstriction, along with impaired endothelial NO relaxation.
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Affiliation(s)
- Ana Cristina Martínez
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Medardo Hernández
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Susana Novella
- Departamento de Fisiología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain
| | - María Pilar Martínez
- Departamento de Anatomía y Anatomía Patológica Comparadas, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain
| | - Rosa María Pagán
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Carlos Hermenegildo
- Departamento de Fisiología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain
| | - Albino García-Sacristán
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Dolores Prieto
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Sara Benedito
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
- * E-mail:
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Del Pozzi AT, Pandey A, Medow MS, Messer ZR, Stewart JM. Blunted cerebral blood flow velocity in response to a nitric oxide donor in postural tachycardia syndrome. Am J Physiol Heart Circ Physiol 2014; 307:H397-404. [PMID: 24878770 DOI: 10.1152/ajpheart.00194.2014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cognitive deficits are characteristic of postural tachycardia syndrome (POTS). Intact nitrergic nitric oxide (NO) is important to cerebral blood flow (CBF) regulation, neurovascular coupling, and cognitive efficacy. POTS patients often experience defective NO-mediated vasodilation caused by oxidative stress. We have previously shown dilation of the middle cerebral artery in response to a bolus administration of the NO donor sodium nitroprusside (SNP) in healthy volunteers. In the present study, we hypothesized a blunted middle cerebral artery response to SNP in POTS. We used combined transcranial Doppler-ultrasound to measure CBF velocity and near-infrared spectroscopy to measure cerebral hemoglobin oxygenation while subjects were in the supine position. The responses of 17 POTS patients were compared with 12 healthy control subjects (age: 14-28 yr). CBF velocity in POTS patients and control subjects were not different at baseline (75 ± 3 vs. 71 ± 2 cm/s, P = 0.31) and decreased to a lesser degree with SNP in POTS patients (to 71 ± 3 vs. 62 ± 2 cm/s, P = 0.02). Changes in total and oxygenated hemoglobin (8.83 ± 0.45 and 8.13 ± 0.48 μmol/kg tissue) were markedly reduced in POTS patients compared with control subjects (14.2 ± 1.4 and 13.6 ± 1.6 μmol/kg tissue), primarily due to increased venous efflux. The data indicate reduced cerebral oxygenation, blunting of cerebral arterial vasodilation, and heightened cerebral venodilation. We conclude, based on the present study outcomes, that decreased bioavailability of NO is apparent in the vascular beds, resulting in a downregulation of NO receptor sites, ultimately leading to blunted responses to exogenous NO.
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Affiliation(s)
- Andrew T Del Pozzi
- Departments of Pediatrics and Physiology, New York Medical College, Center for Hypotension, Hawthorne, New York
| | - Akash Pandey
- Departments of Pediatrics and Physiology, New York Medical College, Center for Hypotension, Hawthorne, New York
| | - Marvin S Medow
- Departments of Pediatrics and Physiology, New York Medical College, Center for Hypotension, Hawthorne, New York
| | - Zachary R Messer
- Departments of Pediatrics and Physiology, New York Medical College, Center for Hypotension, Hawthorne, New York
| | - Julian M Stewart
- Departments of Pediatrics and Physiology, New York Medical College, Center for Hypotension, Hawthorne, New York
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25
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A comparison of histamine effects on the sympathetic neurotransmission of testicular capsule and rat vas deferens. Naunyn Schmiedebergs Arch Pharmacol 2014; 387:719-31. [DOI: 10.1007/s00210-014-0979-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 03/30/2014] [Indexed: 11/26/2022]
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26
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Muoio V, Persson PB, Sendeski MM. The neurovascular unit - concept review. Acta Physiol (Oxf) 2014; 210:790-8. [PMID: 24629161 DOI: 10.1111/apha.12250] [Citation(s) in RCA: 327] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/01/2013] [Accepted: 01/27/2014] [Indexed: 01/01/2023]
Abstract
The cerebral hyperaemia is one of the fundamental mechanisms for the central nervous system homeostasis. Due also to this mechanism, oxygen and nutrients are maintained in satisfactory levels, through vasodilation and vasoconstriction. The brain hyperaemia, or coupling, is accomplished by a group of cells, closely related to each other; called neurovascular unit (NVU). The neurovascular unit is composed by neurones, astrocytes, endothelial cells of blood-brain barrier (BBB), myocytes, pericytes and extracellular matrix components. These cells, through their intimate anatomical and chemical relationship, detect the needs of neuronal supply and trigger necessary responses (vasodilation or vasoconstriction) for such demands. Here, we review the concepts of NVU, the coupling mechanisms and research strategies.
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Affiliation(s)
- V. Muoio
- Institut für Vegetative Physiologie; Charite- Universisitätmedizin Berlin; Berlin Germany
| | - P. B. Persson
- Institut für Vegetative Physiologie; Charite- Universisitätmedizin Berlin; Berlin Germany
| | - M. M. Sendeski
- Institut für Vegetative Physiologie; Charite- Universisitätmedizin Berlin; Berlin Germany
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27
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Cellek S, Cameron NE, Cotter MA, Fry CH, Ilo D. Microvascular dysfunction and efficacy of PDE5 inhibitors in BPH–LUTS. Nat Rev Urol 2014; 11:231-41. [DOI: 10.1038/nrurol.2014.53] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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28
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Skow RJ. Output vs. outcome: neurovascular transduction at rest. J Physiol 2014; 592:257-8. [DOI: 10.1113/jphysiol.2013.266114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Rachel J. Skow
- Faculty of Physical Education and Recreation; University of Alberta; Edmonton Alberta Canada
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29
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Burnstock G, Ralevic V. Purinergic signaling and blood vessels in health and disease. Pharmacol Rev 2013; 66:102-92. [PMID: 24335194 DOI: 10.1124/pr.113.008029] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Purinergic signaling plays important roles in control of vascular tone and remodeling. There is dual control of vascular tone by ATP released as a cotransmitter with noradrenaline from perivascular sympathetic nerves to cause vasoconstriction via P2X1 receptors, whereas ATP released from endothelial cells in response to changes in blood flow (producing shear stress) or hypoxia acts on P2X and P2Y receptors on endothelial cells to produce nitric oxide and endothelium-derived hyperpolarizing factor, which dilates vessels. ATP is also released from sensory-motor nerves during antidromic reflex activity to produce relaxation of some blood vessels. In this review, we stress the differences in neural and endothelial factors in purinergic control of different blood vessels. The long-term (trophic) actions of purine and pyrimidine nucleosides and nucleotides in promoting migration and proliferation of both vascular smooth muscle and endothelial cells via P1 and P2Y receptors during angiogenesis and vessel remodeling during restenosis after angioplasty are described. The pathophysiology of blood vessels and therapeutic potential of purinergic agents in diseases, including hypertension, atherosclerosis, ischemia, thrombosis and stroke, diabetes, and migraine, is discussed.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London NW3 2PF, UK; and Department of Pharmacology, The University of Melbourne, Australia.
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30
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Schmerbach K, Patzak A. Pathophysiological mechanisms in acute mountain sickness. Acta Physiol (Oxf) 2013; 209:246-9. [PMID: 24119164 DOI: 10.1111/apha.12175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- K. Schmerbach
- Institute of Vegetative Physiology; Charité-Universitätsmedizin Berlin; Berlin Germany
| | - A. Patzak
- Institute of Vegetative Physiology; Charité-Universitätsmedizin Berlin; Berlin Germany
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31
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Stewart JM. Update on the theory and management of orthostatic intolerance and related syndromes in adolescents and children. Expert Rev Cardiovasc Ther 2013; 10:1387-99. [PMID: 23244360 DOI: 10.1586/erc.12.139] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Orthostasis means standing upright. One speaks of orthostatic intolerance (OI) when signs, such as hypotension, and symptoms, such as lightheadedness, occur when upright and are relieved by recumbence. The experience of transient mild OI is part of daily life. 'Initial orthostatic hypotension' on rapid standing is a normal form of OI. However, other people experience OI that seriously interferes with quality of life. These include episodic acute OI, in the form of postural vasovagal syncope, and chronic OI, in the form of postural tachycardia syndrome. Less common is neurogenic orthostatic hypotension, which is an aspect of autonomic failure. Normal orthostatic physiology and potential mechanisms for OI are discussed, including forms of sympathetic hypofunction, forms of sympathetic hyperfunction and OI that results from regional blood volume redistribution. General and specific treatment options are proposed.
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Affiliation(s)
- Julian M Stewart
- Departments of Pediatrics, Physiology and Medicine, The Maria Fareri Childrens Hospital and New York Medical College, Valhalla, NY, USA.
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Abstract
The autonomic nervous system, adequate blood volume, and intact skeletal and respiratory muscle pumps are essential components for rapid cardiovascular adjustments to upright posture (orthostasis). Patients lacking sufficient blood volume or having defective sympathetic adrenergic vasoconstriction develop orthostatic hypotension (OH), prohibiting effective upright activities. OH is one form of orthostatic intolerance (OI) defined by signs, such as hypotension, and symptoms, such as lightheadedness, that occur when upright and are relieved by recumbence. Mild OI is commonly experienced during intercurrent illnesses and when standing up rapidly. The latter is denoted "initial OH" and represents a normal cardiovascular adjustment to the blood volume shifts during standing. Some people experience episodic acute OI, such as postural vasovagal syncope (fainting), or chronic OI, such as postural tachycardia syndrome, which can significantly reduce quality of life. The lifetime incidence of ≥1 fainting episodes is ∼40%. For the most part, these episodes are benign and self-limited, although frequent syncope episodes can be debilitating, and injury may occur from sudden falls. In this article, mechanisms for OI having components of adrenergic hypofunction, adrenergic hyperfunction, hyperpnea, and regional blood volume redistribution are discussed. Therapeutic strategies to cope with OI are proposed.
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Affiliation(s)
- Julian M. Stewart
- Departments of Pediatrics, Physiology, and Medicine, The Maria Fareri Children’s Hospital and New York Medical College, Valhalla, New York
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33
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Persson PB, Bondke Persson A. Nitric oxide: a classic revisited. Acta Physiol (Oxf) 2013; 207:427-9. [PMID: 23384421 DOI: 10.1111/apha.12052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Berg T, Jensen J. Tyramine Reveals Failing α2-Adrenoceptor Control of Catecholamine Release and Total Peripheral Vascular Resistance in Hypertensive Rats. Front Neurol 2013; 4:19. [PMID: 23450822 PMCID: PMC3584258 DOI: 10.3389/fneur.2013.00019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 02/11/2013] [Indexed: 11/13/2022] Open
Abstract
α2-Adrenoceptor-activation lowers central sympathetic output, peripheral, vesicular norepinephrine release, epinephrine secretion, and modulates vascular tension. We previously demonstrated that α2-adrenoceptor-mediated inhibition of basal norepinephrine release was not reflected in plasma unless re-uptake through the norepinephrine transporter (NET) was blocked. Tyramine activates reverse norepinephrine transport through NET. Here we tested the hypothesis that tyramine, by engaging NET in release, also blocks re-uptake, and therefore allows manipulation of pre-junctional α2-adrenoceptors to directly regulate norepinephrine overflow to plasma. We compared in anesthetized spontaneously hypertensive rats (SHRs) and normotensive controls (WKYs), the effect of α2-adrenoreceptor antagonist (L-659,066) and/or agonist (clonidine) on norepinephrine overflow and increase in total peripheral vascular resistance (TPR) evoked by tyramine-infusion (1.26 μmol/min/kg, 15 min) and epinephrine secretion activated by the surgical stress. TPR was computed as blood pressure divided by cardiac output, recorded as ascending aortic flow. Plasma catecholamine concentrations after tyramine were higher in SHRs than WKYs. Pre-treatment with L-659,066 increased the catecholamine concentrations in WKYs, but only if combined with clonidine in SHRs. Clonidine alone reduced tyramine-induced norepinephrine overflow in SHRs, and epinephrine in both strains. Tyramine-induced increase in TPR was not different after clonidine, eliminated after L-659,066 and L-659,066 + clonidine in WKYs, but only after L-659,066 + clonidine in SHRs. We conclude that tyramine-infusion does allow presynaptic regulation of vesicular release to be accurately assessed by measuring differences in plasma norepinephrine concentration. Our results indicate that presynaptic α2-adrenoceptor regulation of norepinephrine release from nerve vesicles and epinephrine secretion is dysfunctional in SHRs, but can be restored by clonidine.
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Affiliation(s)
- Torill Berg
- Department of Physiology, Institute of Basic Medical Sciences, University of Oslo Oslo, Norway
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35
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Abstract
Autonomic testing is used to define the role of the autonomic nervous system in diverse clinical and research settings. Because most of the autonomic nervous system is inaccessible to direct physiological testing, in the clinical setting the most widely used techniques entail the assessment of an end-organ response to a physiological provocation. The noninvasive measures of cardiovascular parasympathetic function involve the assessment of heart rate variability while the measures of cardiovascular sympathetic function assess the blood pressure response to physiological stimuli. Tilt-table testing, with or without pharmacological provocation, has become an important tool in the assessment of a predisposition to neurally mediated (vasovagal) syncope, the postural tachycardia syndrome, and orthostatic hypotension. Distal, postganglionic, sympathetic cholinergic (sudomotor) function may be evaluated by provoking axon reflex mediated sweating, e.g., the quantitative sudomotor axon reflex (QSART) or the quantitative direct and indirect axon reflex (QDIRT). The thermoregulatory sweat test provides a nonlocalizing measure of global pre- and postganglionic sudomotor function. Frequency domain analyses of heart rate and blood pressure variability, microneurography, and baroreflex assessment are currently research tools but may find a place in the clinical assessment of autonomic function in the future.
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Affiliation(s)
- Roy Freeman
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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36
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Bohlender J, Nussberger J, Imboden H. Angiotensinergic innervation of the kidney: present knowledge and its significance. Curr Hypertens Rep 2012. [PMID: 23197298 DOI: 10.1007/s11906-012-0322-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Intrarenal neurotransmission implies the co-release of neuropeptides at the neuro-effector junction with direct influence on parameters of kidney function. The presence of an angiotensin (Ang) II-containing phenotype in catecholaminergic postganglionic and sensory fibers of the kidney, based on immunocytological investigations, has only recently been reported. These angiotensinergic fibers display a distinct morphology and intrarenal distribution, suggesting anatomical and functional subspecialization linked to neuronal Ang II-expression. This review discusses the present knowledge concerning these fibers, and their significance for renal physiology and the pathogenesis of hypertension in light of established mechanisms. The data suggest a new role of Ang II as a co-transmitter stimulating renal target cells or modulating nerve traffic from or to the kidney. Neuronal Ang II is likely to be an independent source of intrarenal Ang II. Further physiological experimentation will have to explore the role of the angiotensinergic renal innervation and integrate it into existing concepts.
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Affiliation(s)
- Jürgen Bohlender
- Hôpital fribourgeois/CHUV and Institute of Cell Biology, University of Bern, Case postale, Fribourg, Switzerland.
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37
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Abstract
Sympathetic circulatory control is key to the rapid cardiovascular adjustments that occur within seconds of standing upright (orthostasis) and which are required for bipedal stance. Indeed, patients with ineffective sympathetic adrenergic vasoconstriction rapidly develop orthostatic hypotension, prohibiting effective upright activities. One speaks of orthostatic intolerance (OI) when signs, such as hypotension, and symptoms, such as lightheadedness, occur when upright and are relieved by recumbence. The experience of transient mild OI is part of daily life. However, many people experience episodic acute OI as postural faint or chronic OI in the form of orthostatic tachycardia and orthostatic hypotension that significantly reduce the quality of life. Potential mechanisms for OI are discussed including forms of sympathetic hypofunction, forms of sympathetic hyperfunction, and OI that results from regional blood volume redistribution attributable to regional adrenergic hypofunction.
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Affiliation(s)
- Julian M Stewart
- Departments of Physiology, Pediatrics and Medicine, New York Medical College, Valhalla, NY, USA. mail:
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Persson PB. Carl Friedrich Wilhelm Ludwig, a fabled physiologist and mentor of Scandinavian Physiology Announcing the Carl Ludwig Award for young authors in Acta Physiologica (Oxford). Acta Physiol (Oxf) 2012; 204:289-90. [PMID: 22300128 DOI: 10.1111/j.1748-1716.2012.02405.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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