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Pereira-Acácio A, Veloso-Santos JPM, Nossar LF, Costa-Sarmento G, Muzi-Filho H, Vieyra A. Angiotensin-(3–4) normalizes the elevated arterial blood pressure and abnormal Na+/energy handling associated with chronic undernutrition by counteracting the effects mediated by type 1 angiotensin II receptors. PLoS One 2022; 17:e0273385. [PMID: 35984814 PMCID: PMC9390919 DOI: 10.1371/journal.pone.0273385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 08/07/2022] [Indexed: 11/24/2022] Open
Abstract
We investigated the mechanisms by which chronic administration of a multideficient diet after weaning alters bodily Na+ handling, and culminates in high systolic blood pressure (SBP) at a juvenile age. From 28 to 92 days of age, weaned male Wistar rats were given a diet with low content and poor-quality protein, and low lipid, without vitamin supplementation, which mimics the diets consumed in impoverished regions worldwide. We measured food, energy and Na+ ingestion, together with urinary Na+ excretion, Na+ density (Na+ intake/energy intake), plasma Na+ concentration, SBP, and renal proximal tubule Na+-transporting ATPases. Undernourished rats aged 92 days had only one-third of the control body mass, lower plasma albumin, higher SBP, higher energy intake, and higher positive Na+ balance accompanied by decreased plasma Na+ concentration. Losartan or Ang-(3–4) normalized SBP, and the combination of the 2 substances induced an accentuated negative Na+ balance as a result of strong inhibition of Na+ ingestion. Na+ density in undernourished rats was higher than in control, irrespective of the treatment, and they had downregulated (Na++K+)ATPase and upregulated Na+-ATPase in proximal tubule cells, which returned to control levels after Losartan or Ang-(3–4). We conclude that Na+ density, not only Na+ ingestion, plays a central role in the pathophysiology of elevated SBP in chronically undernourished rats. The observations that Losartan and Ang-(3–4) normalized SBP together with negative Na+ balance give support to the proposal that Ang II⇒AT1R and Ang II⇒AT2R axes have opposite roles within the renin-angiotensin-aldosterone system of undernourished juvenile rats.
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Affiliation(s)
- Amaury Pereira-Acácio
- Graduate Program of Translational Biomedicine/BIOTRANS, University of Grande Rio, Duque de Caxias, Brazil
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Center of Structural Biology and Bioimaging/CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - João P. M. Veloso-Santos
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Center of Structural Biology and Bioimaging/CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luiz F. Nossar
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gloria Costa-Sarmento
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Center of Structural Biology and Bioimaging/CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Humberto Muzi-Filho
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Center of Structural Biology and Bioimaging/CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Adalberto Vieyra
- Graduate Program of Translational Biomedicine/BIOTRANS, University of Grande Rio, Duque de Caxias, Brazil
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Center of Structural Biology and Bioimaging/CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Regenerative Medicine/REGENERA, Rio de Janeiro, Brazil
- * E-mail:
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Kuczeriszka M, Wąsowicz K. Animal models of hypertension: The status of nitric oxide and oxidative stress and the role of the renal medulla. Nitric Oxide 2022; 125-126:40-46. [PMID: 35700961 DOI: 10.1016/j.niox.2022.06.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 05/22/2022] [Accepted: 06/09/2022] [Indexed: 12/21/2022]
Abstract
Hypertension significantly contributes to overall morbidity and mortality worldwide, and animal models of hypertension provide important tools to verify the physiological and molecular mechanisms underlying the development of the disease. A review of the most important models available would provide an insight into the appropriate targets to be addressed in the treatment of different forms of human hypertension. In the animal models discussed a special attention is given to the status and pathophysiological role of nitric oxide and its interaction with reactive oxygen species and oxidative stress. Another focus of the review are the processes running in the renal medulla which are still insufficiently explored. Deficient nitric oxide synthesis and its reduced bioavailability are important determinants of hypertension since NO is recognized as a major control factor of vascular tone homeostasis. For decades perfusion of the renal medulla has also been regarded as one of the blood pressure control factors and, noteworthily, the renal medulla belongs to the tissues with the highest NO content. The list of most often applied animal hypertension models reviewed here includes variants of salt-induced hypertension, the models with genetic background: such as spontaneously hypertensive rats (SHR) and Dahl salt sensitive (SS/SR) rats, Goldblatt 2K-1C hypertensive rats, and also the pharmacologically-plus-dietary salt-induced model known as DOCA-salt hypertension.
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Affiliation(s)
- Marta Kuczeriszka
- Department of Renal and Body Fluid Physiology, M. Mossakowski Medical Research Institute, Polish Academy of Sciences, 02-106, Warsaw, A. Pawinskiego 5, Poland.
| | - Krzysztof Wąsowicz
- Department of Pathophysiology, Forensic Veterinary Medicine and Administration, University of Warmia and Mazury in Olsztyn, 10-719, Olsztyn, Oczapowskiego 13, Poland
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Roles of sleep-related cardiovascular autonomic functions in voluntary-exercise-induced alleviation of hypertension in spontaneously hypertensive rats. Hypertens Res 2022; 45:1154-1167. [PMID: 35459851 DOI: 10.1038/s41440-022-00916-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 03/03/2022] [Accepted: 03/08/2022] [Indexed: 12/12/2022]
Abstract
Autonomic dysfunction and sleep problems are closely associated with hypertension and predict cardiovascular morbidity and mortality. Animal studies and clinical observations have identified exercise as an important factor in preventing and treating hypertension. However, the roles of autonomic function and sleep in the antihypertensive mechanisms of exercise are still not fully understood. This study aimed to clarify the physiological mechanisms associated with autonomic function and sleep through wheel exercise. Male spontaneously hypertensive rats (SHRs) were grouped into a wheel-exercised group and a sedentary group (controls). Electroencephalogram, electromyogram, electrocardiogram, and mean arterial pressure (MAP) were recorded simultaneously for 24 h once a week over 11 weeks. Wheel exercise was initiated in the SHRs at 12 weeks old and continued for another eight weeks. A significant suppression in the age-related elevation of MAP was noted in the SHRs undergoing wheel exercise. The reduction in MAP was correlated with increased parasympathetic activity and baroreflex sensitivity and decreased sympathetic activity, mainly during quiet sleep. Exercise increased the paradoxical sleep time and theta power (associated with cognitive function) but not the delta power (an indicator of sleep depth) or the attenuation of circadian rhythm flattening (characterized by increased wakefulness and less sleep during the light period and the opposite during the dark period). Furthermore, the exercise-induced changes in autonomic function occurred before those in sleep patterns, which were dependent on each other. In conclusion, wheel exercise can modulate sleep-related cardiovascular dysfunction and the flattening of circadian rhythm, preventing the progression of hypertension, which reduces the incidence of cardiovascular diseases.
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Zou S, Shimizu T, Yamamoto M, Shimizu S, Higashi Y, Karashima T, Saito M. Age-related differences in responses to hydrogen sulfide in the bladder of spontaneously hypertensive rats. Int J Urol 2021; 28:459-465. [PMID: 33403726 DOI: 10.1111/iju.14478] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/29/2020] [Indexed: 12/01/2022]
Abstract
OBJECTIVES To investigate whether a response to hydrogen sulfide donors (GYY4137 and sodium hydrosulfide) and the endogenous hydrogen sulfide system (hydrogen sulfide level and expression of cysteine aminotransferase, cystathionine β-synthase, cystathionine γ-lyase, and 3-mercaptopyruvate sulfurtransferase) in the spontaneously hypertensive rat bladder differ with age, we compared the responses of hydrogen sulfide donors to micturition and bladder relaxation, and the endogenous hydrogen sulfide system in the bladder of 18-week versus 12-week-old spontaneously hypertensive rats. METHODS GYY4137 was intravesically administered and cystometry was performed in anesthetized rats. The responses of sodium hydrosulfide were evaluated in carbachol-mediated precontracted bladder strips. Bladder hydrogen sulfide levels and expression levels of each enzyme were investigated using the methylene blue method and Western blotting, respectively. RESULTS GYY4137 treatment significantly prolonged intercontraction intervals only in 12-week-old rats. Sodium hydrosulfide-induced bladder relaxation was significantly attenuated in the strips of 18-week-old rats compared with that in 12-week-old rats. In the bladder dome, significant increases in hydrogen sulfide levels and in the expression of cystathionine β-synthase, 3-mercaptopyruvate sulfurtransferase, and cysteine aminotransferase were observed in 18-week-old rats compared with 12-week-old rats. However, cystathionine γ-lyase bands were not detected in bladder tissues of either group. CONCLUSIONS Bladder relaxation induced by hydrogen sulfide may be attenuated in spontaneously hypertensive rats in an age-dependent manner.
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Affiliation(s)
- Suo Zou
- Departments of, Department of, Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Takahiro Shimizu
- Departments of, Department of, Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Masaki Yamamoto
- Departments of, Department of, Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Shogo Shimizu
- Departments of, Department of, Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Youichirou Higashi
- Departments of, Department of, Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Takashi Karashima
- Department of, Urology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Motoaki Saito
- Departments of, Department of, Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
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Luo W, Wang Y, Yang H, Dai C, Hong H, Li J, Liu Z, Guo Z, Chen X, He P, Li Z, Li F, Jiang J, Liu P, Li Z. Heme oxygenase-1 ameliorates oxidative stress-induced endothelial senescence via regulating endothelial nitric oxide synthase activation and coupling. Aging (Albany NY) 2019; 10:1722-1744. [PMID: 30048241 PMCID: PMC6075439 DOI: 10.18632/aging.101506] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/20/2018] [Indexed: 12/20/2022]
Abstract
AIM Premature senescence of vascular endothelial cells is a leading cause of various cardiovascular diseases. Therapies targeting endothelial senescence would have important clinical implications. The present study was aimed to evaluate the potential of heme oxygenase-1 (HO-1) as a therapeutic target for endothelial senescence. METHODS AND RESULTS Upregulation of HO-1 by Hemin or adenovirus infection reversed H2O2-induced senescence in human umbilical vein endothelial cells (HUVECs); whereas depletion of HO-1 by siRNA or HO-1 inhibitor protoporphyrin IX zinc (II) (ZnPP) triggered HUVEC senescence. Mechanistically, overexpression of HO-1 enhanced the interaction between HO-1 and endothelial nitric oxide synthase (eNOS), and promoted the interaction between eNOS and its upstream kinase Akt, thus resulting in an enhancement of eNOS phosphorylation at Ser1177 and a subsequent increase of nitric oxide (NO) production. Moreover, HO-1 induction prevented the decrease of eNOS dimer/monomer ratio stimulated by H2O2 via its antioxidant properties. Contrarily, HO-1 silencing impaired eNOS phosphorylation and accelerated eNOS uncoupling. In vivo, Hemin treatment alleviated senescence of endothelial cells of the aorta from spontaneously hypertensive rats, through upregulating eNOS phosphorylation at Ser1177. CONCLUSIONS HO-1 ameliorated endothelial senescence through enhancing eNOS activation and defending eNOS uncoupling, suggesting that HO-1 is a potential target for treating endothelial senescence.
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Affiliation(s)
- Wenwei Luo
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yu Wang
- Infinitus (China) Co. Ltd, Guangzhou 510663, China
| | - Hanwei Yang
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, 510006, China
| | - Chunmei Dai
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, 510006, China
| | - Huiling Hong
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, 510006, China
| | - Jingyan Li
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, 510006, China
| | - Zhiping Liu
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, 510006, China
| | - Zhen Guo
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, 510006, China
| | - Xinyi Chen
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, 510006, China
| | - Ping He
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, 510006, China
| | - Ziqing Li
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, 510006, China
| | - Fang Li
- College of Life Science, South China Agricultural University, Guangzhou 510642, China
| | - Jianmin Jiang
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, 510006, China
| | - Peiqing Liu
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, 510006, China
| | - Zhuoming Li
- Laboratory of Pharmacology and Toxicology, School of Pharmaceutical Sciences; National and Local United Engineering Lab of Druggability and New Drugs Evaluation; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Sun Yat-sen University, Guangzhou, 510006, China
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Wang H, Jiang H, Liu H, Zhang X, Ran G, He H, Liu X. Modeling Disease Progression: Angiotensin II Indirectly Inhibits Nitric Oxide Production via ADMA Accumulation in Spontaneously Hypertensive Rats. Front Physiol 2016; 7:555. [PMID: 27909412 PMCID: PMC5112235 DOI: 10.3389/fphys.2016.00555] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 11/03/2016] [Indexed: 01/07/2023] Open
Abstract
Nitric oxide (NO) production impairment is involved in the onset and development of hypertension. Although NO production impairment in spontaneously hypertensive rat (SHR) has been reported in a variety of researches, the time course of this progressive procedure, as well as its relationship with asymmetric dimethylarginine (ADMA) and angiotensin II (Ang II), has not been quantified. The aim of this research is to establish a mechanism-based disease progression model to assess Ang II and ADMA's inhibition of NO production in SHR's disease progression with/without ramipril's intervention. SHR were randomly divided into three groups: one disease group (n = 8) and two treatment groups (n = 8 for each group): standard treatment group (receiving ramipril 2 mg/kg*day) and intensive treatment group (receiving ramipril 10 mg/kg*day). ADMA, Ang II, NO, and SBP were determined weekly. Intensive treatment with ramipril was found to have no further attenuation of plasma NO and ADMA than standard treatment beyond its significantly stronger antihypertensive effects. Four linked turnover models were developed to characterize the profiles of ADMA, Ang II, NO, and SBP during hypertensive disease progression with/without ramipril intervention. Our model described Ang II and ADMA's contribution to NO production impairment and their responses to ramipril treatment throughout the disease progression in SHR. Model simulations suggested that Ang II affected NO production mainly through inhibiting ADMA elimination rather than affecting nitric oxide synthase (NOS) directly.
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Affiliation(s)
- Haidong Wang
- Center of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University Nanjing, China
| | - Hao Jiang
- Center of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University Nanjing, China
| | - Haochen Liu
- Center of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University Nanjing, China
| | - Xue Zhang
- Center of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University Nanjing, China
| | - Guimei Ran
- Center of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University Nanjing, China
| | - Hua He
- Center of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University Nanjing, China
| | - Xiaoquan Liu
- Center of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University Nanjing, China
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Ahmeda AF, Alzoghaibi M. Factors regulating the renal circulation in spontaneously hypertensive rats. Saudi J Biol Sci 2015; 23:441-51. [PMID: 27298576 PMCID: PMC4890190 DOI: 10.1016/j.sjbs.2015.06.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 06/14/2015] [Accepted: 06/19/2015] [Indexed: 01/17/2023] Open
Abstract
Hypertension is one of the leading causes of health morbidity and mortality which are linked to many life threatening diseases such as stroke heart problems and renal dysfunction. The integrity of renal microcirculation is crucial to maintaining the clearance and the excretory function in the normotensive and hypertensive conditions. Furthermore, any alteration in the renal function is involved in the pathophysiology of hypertension. The aim of this review is to provide a brief discussion of some factors that regulate renal haemodynamics in spontaneously hypertensive rats, an animal model of hypertension, and how these factors are linked to the disease.
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Affiliation(s)
- Ahmad F Ahmeda
- Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Mohammed Alzoghaibi
- Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
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8
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Ahmad FUD, Sattar MA, Rathore HA, Tan YC, Akhtar S, Jin OH, Pei YP, Abdullah NA, Johns EJ. Hydrogen sulphide and tempol treatments improve the blood pressure and renal excretory responses in spontaneously hypertensive rats. Ren Fail 2014; 36:598-605. [PMID: 24502512 DOI: 10.3109/0886022x.2014.882218] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Oxidative stress and suppressed H2S production lead to increased renal vascular resistance, disturbed glomerular hemodynamics, and abnormal renal sodium and water handling, contribute to the pathogenesis and maintenance of essential hypertension in man and the spontaneously hypertensive rat. This study investigated the impact of H2S and tempol alone and in combination on blood pressure and renal hemodynamics and excretory functions in the SHR. Groups of WKY rats or SHR (n=6) were treated for 4 weeks either as controls or received NaHS (SHR+NaHS), tempol (SHR+Tempol), or NaHS plus tempol (SHR+NaHS +Tempol). Metabolic studies were performed on days 0, 14, and 28, thereafter animals were anaesthetized to measure renal hemodynamics and plasma oxidative and antioxidant markers. SHR control rats had higher mean arterial blood pressure (140.0 ± 2 vs. 100.0 ± 3 mmHg), lower plasma and urinary H2S, creatinine clearance, urine flow rate and urinary sodium excretion, and oxidative stress compared to WKY (all p<0.05). Treatment either with NaHS or with tempol alone decreased blood pressure and oxidative stress and improved renal hemodynamic and excretory function compared to untreated SHR. Combined NaHS and tempol therapy in SHRs caused larger decreases in blood pressure (∼20-22% vs. ∼11-15% and ∼10-14%), increases in creatinine clearance, urinary sodium excretion and fractional sodium excretion and up-regulated the antioxidant status compared to each agent alone (all p<0.05). These findings demonstrated that H2S and tempol together resulted in greater reductions in blood pressure and normalization of kidney function compared with either compound alone.
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Affiliation(s)
- Fiaz Ud Din Ahmad
- Department of Physiology, School of Pharmaceutical Sciences, Universiti Sains Malaysia , Penang , Malaysia
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Ito D, Ito O, Cao P, Mori N, Suda C, Muroya Y, Takashima K, Ito S, Kohzuki M. Effects of exercise training on nitric oxide synthase in the kidney of spontaneously hypertensive rats. Clin Exp Pharmacol Physiol 2013; 40:74-82. [DOI: 10.1111/1440-1681.12040] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2012] [Revised: 11/30/2013] [Accepted: 12/03/2012] [Indexed: 02/06/2023]
Affiliation(s)
- Daisuke Ito
- Department of Internal Medicine and Rehabilitation Science; Tohoku University Graduate School of Medicine; Sendai; Japan
| | | | - Pengyu Cao
- Department of Internal Medicine and Rehabilitation Science; Tohoku University Graduate School of Medicine; Sendai; Japan
| | | | - Chihiro Suda
- Department of Internal Medicine and Rehabilitation Science; Tohoku University Graduate School of Medicine; Sendai; Japan
| | - Yoshikazu Muroya
- Department of Internal Medicine and Rehabilitation Science; Tohoku University Graduate School of Medicine; Sendai; Japan
| | - Kenta Takashima
- Department of Internal Medicine and Rehabilitation Science; Tohoku University Graduate School of Medicine; Sendai; Japan
| | - Sadayoshi Ito
- Center for Advanced Integrated Renal Science; Tohoku University Graduate School of Medicine; Sendai; Japan
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Bonilla IM, Sridhar A, Györke S, Cardounel AJ, Carnes CA. Nitric oxide synthases and atrial fibrillation. Front Physiol 2012; 3:105. [PMID: 22536189 PMCID: PMC3332924 DOI: 10.3389/fphys.2012.00105] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2012] [Accepted: 04/02/2012] [Indexed: 11/13/2022] Open
Abstract
Oxidative stress has been implicated in the pathogenesis of atrial fibrillation. There are multiple systems in the myocardium which contribute to redox homeostasis, and loss of homeostasis can result in oxidative stress. Potential sources of oxidants include nitric oxide synthases (NOS), which normally produce nitric oxide in the heart. Two NOS isoforms (1 and 3) are normally expressed in the heart. During pathologies such as heart failure, there is induction of NOS 2 in multiple cell types in the myocardium. In certain conditions, the NOS enzymes may become uncoupled, shifting from production of nitric oxide to superoxide anion, a potent free radical and oxidant. Multiple lines of evidence suggest a role for NOS in the pathogenesis of atrial fibrillation. Therapeutic approaches to reduce atrial fibrillation by modulation of NOS activity may be beneficial, although further investigation of this strategy is needed.
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Affiliation(s)
- Ingrid M Bonilla
- College of Pharmacy, The Ohio State University Columbus, OH, USA
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Kong X, Zhang DY, Wu HB, Li FX. Losartan and pioglitazone ameliorate nephropathy in experimental metabolic syndrome rats. Biol Pharm Bull 2011; 34:693-9. [PMID: 21532159 DOI: 10.1248/bpb.34.693] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is well known that metabolic syndrome (MS) is a risk factor for proteinuria and chronic kidney disease. Losartan (angiotensin II receptor blocker, ARB) and pioglitazone (peroxisome proliferator-activated receptor-γ, PPARγ agonist) have been shown to confer renoprotection. However, to date, whether or not an ARB and a PPARγ agonist have synergistic renoprotective effects remains controversial. Thus, the present study was designed to evaluate a combined treatment with losartan and pioglitazone in Sprague-Dawley rats fed with a high-fat, high-salt (HFS) diet and 20% sucrose solution for 16 weeks, an animal model of MS accompanying with renal lesions. Losartan, pioglitazone, and their combination were orally administered in the MS rats from 8 weeks to the end of this study. At 16 weeks, the MS rats showed the elevation in systolic blood pressure (SBP), urinary albumin excretion (UAE), and glomerulosclerosis (GS) score, but creatinine clearance, urinary protein excretion, and score of tubulointerstitial damage were not affected. Renal vascular endothelial growth factor (VEGF) protein level, mRNA and protein expression, which were respectively measured by enzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (RT-PCR), and Western blot analysis, were obviously decreased in the MS rats. Treatment with the combination of losartan and pioglitazone provided synergistic effects in reducing the SBP, UAE, and GS score when compared with monotherapy. These effects were not associated with ameliorated the downregulation of renal VEGF expression. Our data suggest that combined treatment with losartan and pioglitazone may offer additional advantages in treating MS nephropathy.
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Affiliation(s)
- Xiang Kong
- Department of Pharmacology, Third-Grade Pharmacology Laboratory of State Administration of Traditional Chinese Medicine, Wannan Medical College, Anhui, China
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12
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Alonso F, Boittin FX, Bény JL, Haefliger JA. Loss of connexin40 is associated with decreased endothelium-dependent relaxations and eNOS levels in the mouse aorta. Am J Physiol Heart Circ Physiol 2010; 299:H1365-73. [PMID: 20802140 DOI: 10.1152/ajpheart.00029.2010] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Upon agonist stimulation, endothelial cells trigger smooth muscle relaxation through the release of relaxing factors such as nitric oxide (NO). Endothelial cells of mouse aorta are interconnected by gap junctions made of connexin40 (Cx40) and connexin37 (Cx37), allowing the exchange of signaling molecules to coordinate their activity. Wild-type (Cx40(+/+)) and hypertensive Cx40-deficient mice (Cx40(-/-)), which also exhibit a marked decrease of Cx37 in the endothelium, were used to investigate the link between the expression of endothelial connexins (Cx40 and Cx37) and endothelial nitric oxide synthase (eNOS) expression and function in the mouse aorta. With the use of isometric tension measurements in aortic rings precontracted with U-46619, a stable thromboxane A(2) mimetic, we first demonstrate that ACh- and ATP-induced endothelium-dependent relaxations solely depend on NO release in both Cx40(+/+) and Cx40(-/-) mice, but are markedly weaker in Cx40(-/-) mice. Consistently, both basal and ACh- or ATP-induced NO production were decreased in the aorta of Cx40(-/-) mice. Altered relaxations and NO release from aorta of Cx40(-/-) mice were associated with lower expression levels of eNOS in the aortic endothelium of Cx40(-/-) mice. Using immunoprecipitation and in situ ligation assay, we further demonstrate that eNOS, Cx40, and Cx37 tightly interact with each other at intercellular junctions in the aortic endothelium of Cx40(+/+) mice, suggesting that the absence of Cx40 in association with altered Cx37 levels in endothelial cells from Cx40(-/-) mice participate to the decreased levels of eNOS. Altogether, our data suggest that the endothelial connexins may participate in the control of eNOS expression levels and function.
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Affiliation(s)
- Florian Alonso
- Service of Internal Medicine, Laboratory of Experimental Medicine 19–135S, University Hospital, CHUV, Lausanne, Switzerland
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Effects of low protein intake on the development of the remaining kidney in subtotally nephrectomized immature rats: expression of inducible and endothelial NO synthase. Med Mol Morphol 2010; 43:116-22. [PMID: 20683700 DOI: 10.1007/s00795-009-0485-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 11/16/2009] [Indexed: 10/19/2022]
Abstract
We examined the effects of low protein intake on the development of the remaining kidney in subtotally (5/6) nephrectomized immature rats. Three-week-old rats were kept on a diet containing either 12% protein (Lp rats) or 18% protein (Np rats) for 4 or 8 weeks after subtotal nephrectomy (SUNx). In Western blot analysis, the endothelial NO synthase (eNOS) protein expression of the Lp rats was significantly higher than that of the Np rats at 4 weeks after SUNx. Immunohistochemically, more inducible NO synthase (iNOS)-positive cells were observed in the Np rats than in the Lp rats 4 weeks after SUNx in the distal tubules. In semiquantitative RT-PCR, the expression of renin mRNA was significantly lower in the Lp rats than in the Np rats at 4 and 8 weeks after SUNx. These findings reveal that protein restriction is effective in preventing renal failure of immature rats and that the changes in the expression levels of renin, eNOS, and iNOS is involved in the process of this prevention.
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Newaz MA, Yousefipour Z, Nawal NNA. Modulation of Nitric Oxide Synthase Activity in Brain, Liver, and Blood Vessels of Spontaneously Hypertensive Rats by Ascorbic Acid: Protection from Free Radical Injury. Clin Exp Hypertens 2009; 27:497-508. [PMID: 16081342 DOI: 10.1081/ceh-200067681] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
End organ damage in essential hypertension has been linked to increased oxygen free radical generation, reduced antioxidant defense, and/or attenuation of nitric oxide synthase (NOS) activity. Ascorbic acid (AA), a water-soluble antioxidant, has been reported as a strong defense against free radicals in both aqueous and nonaqueous environment. In this study we examined the hypothesis that antioxidant ascorbic acid may confer protection from increased free radical activity in brain, liver, and blood vessels of spontaneously hypertensive rats (SHR). Male SHRs were divided into groups: SHR + AA (treated with AA, 1 mg/rat/day; for 12 weeks) or SHR (untreated). Wister-Kyoto rats (WKY) served as the control. Mean systolic blood pressure (SBP) in treated and untreated SHR was 145 +/- 7 mmHg and 142 +/- 8 mmHg, respectively. AA treatment prevented the increase in systolic blood pressure in SHR by 37 +/- 1% (p < 0.05). NOS activity in the brain, liver, and blood vessels of WKY rat was 1.82 +/- 0.02, 0.14 +/- 0.003, and 1.54 +/- 0.06 pmol citruline/mg protein, respectively. In SHR, total NOS activity was significantly reduced by 52 +/- 1%, 21 +/- 3%, and 44 +/- 4%, respectively. AA increased NOS activity in brain, liver, and blood vessels of SHR from 0.87 +/-.03, 0.11 +/-.01, and 0.87 +/-.08 pmol citruline/mg protein to 0.93 +/- 0.01, 0.13 +/- 0.001, and 1.11 +/- 0.03 pmol citruline/mg protein (p < 0.05), respectively. Lipid peroxides in the brain, liver, and blood vessels from WKY rats were 0.87 +/- 0.06, 0.11 +/- 0.005, and 0.47 +/- 0.04 nmol MDA equiv/mg protein, respectively. In SHR, lipid peroxides in brain, liver, and blood vessels were significantly increased by 40 +/- 3%, 64 +/- 3%, and 104 +/- 13%, respectively. AA reduced lipid peroxidation in liver and blood vessels by 17 +/- 1% and 34 +/- 3% but not in brain. Plasma lipid peroxides were almost doubled in SHR (p < 0.01) together with a reduction in total antioxidant status (6 +/- 0.1%; p < 0.05), nitrite (53 +/- 2%; p < 0.05) and superoxide dismutase (SOD) activity (36 +/- 2%; p < 0.05). AA treatment reduced plasma lipid peroxide (p < 0.001), and increased TAS (p < 0.001), nitrite (p < 0.001), and SOD activity (p < 0.001). From this study, we conclude that brain, liver, and blood vessels in SHR are susceptible to free radical injury, which reduces the availability of NO either by scavenging it or by reducing its production via inhibiting NOS. In addition, brain, liver, and blood vessels in SHR; may be protected by antioxidant, which improves total antioxidant status, and SOD thus may prevent high blood pressure and its complications.
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Affiliation(s)
- M A Newaz
- Center for Cardiovascular Diseases, College of Pharmacy and Health Sciences, Texas Southern University, Houston, Texas 77004, USA.
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Age-related renal disease in female Dahl salt-sensitive rats is attenuated with 17 beta-estradiol supplementation by modulating nitric oxide synthase expression. ACTA ACUST UNITED AC 2008; 5:147-59. [PMID: 18573482 DOI: 10.1016/j.genm.2008.05.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Indexed: 11/18/2022]
Abstract
BACKGROUND The incidence of chronic renal disease in women increases with aging, especially after menopause, suggesting that loss of sex hormones may contribute to the development and progression of renal disease. However, the mechanisms by which sex hormones, particularly estrogens, contribute to the disease process are unclear. OBJECTIVE The present study examined the effects of ovariectomy (OVX) with or without 17 beta-estradiol (E2) supplementation (OVX+E2) on the expression of inducible (iNOS) and endothelial (eNOS) nitric oxide synthase in the kidney. METHODS The study was performed in young (4 months [4M]) and aged (12 months [12M]) female Dahl salt-sensitive rats fed a low-sodium (0.1% NaCl) diet. At 3 months of age, the animals were either subjected to sham surgery, OVX, or OVX with implantation of an E2 silastic pellet. The treatments were administered for either 1 or 9 months, rendering the animals 4 months of age or 12 months of age at the time of sacrifice, respectively. Renal expression of NOS isoforms was measured by Western blotting and immunohistochemistry. RESULTS OVX in the aged rats was associated with 35% and 25% decreases in medullary iNOS (mean [SEM] relative optical density [ROD]: 4M OVX, 1.81 [0.14] vs 12M OVX, 1.17 [0.16]; P < 0.05) and eNOS (mean ROD: 4M OVX, 1.91 [0.09] vs 12M OVX, 1.43 [0.15]; P < 0.05) protein expression, respectively, and a 25-fold increase in the abundance of CD68-positive cells, indicating macrophage infiltration (mean cells/mm2: 4M OVX, 1.18 [0.09] vs 12M OVX, 30.0 [0.74]; P < 0.001). E2 supplementation either partially or completely attenuated these changes in iNOS (mean ROD: 4M OVX+E2, 2.26 [0.08] vs 12M OVX+E2, 1.70 [0.09]; P < 0.05), eNOS (mean ROD: 4M OVX+E2, 2.03 [0.07] vs 12M OVX+E2, 1.77 [0.11]; P = NS) and CD68 (mean cells/mm2: 4M OVX+E2, 1.46 [0.07] vs 12M OVX+E2, 6.87 [1.6]; P < 0.01) associated with OVX in the aging kidney. CONCLUSIONS These data suggest that ovarian E2 loss with aging may contribute to the development of age-related renal disease through downregulation of iNOS and eNOS protein abundance and increased renal inflammation in this animal model. Furthermore, E2 supplementation may be protective in the aging kidney by attenuating these changes.
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Tan HW, Xing SS, Bi XP, Li L, Gong HP, Zhong M, Zhang Y, Zhang W. Felodipine attenuates vascular inflammation in a fructose-induced rat model of metabolic syndrome via the inhibition of NF-kappaB activation. Acta Pharmacol Sin 2008; 29:1051-9. [PMID: 18718174 DOI: 10.1111/j.1745-7254.2008.00843.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
AIM Metabolic syndrome is associated with an increased incidence of atherosclerosis. Clinical studies have shown that calcium channel blockers (CCB) inhibit the progression of atherosclerosis. However, the underlying mechanism is unclear. We investigated the inhibitory effect of felodipine on adhesion molecular expression and macrophage infiltration in the aorta of high fructose-fed rats (FFR). METHODS Male Wistar rats were given 10% fructose in drinking water. After 32 weeks of high fructose feeding, they were treated with felodipine (5 mg x kg(-1) x d(-1)) for 6 weeks. The control rats were given a normal diet and water. The aortic expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and the infiltration of macrophages were measured by real-time RT-PCR and/or immunohistochemistry. NF-kappaB activity was measured by electrophoretic mobility shift assay (EMSA). RESULTS After 32 weeks of high fructose feeding, FFR displayed increased body weight, systolic blood pressure (SBP), serum insulin, and triglycerides when compared with the control rats. The aortic expressions of ICAM-1 and VCAM-1 were significantly increased in FFR than in the control rats and accompanied by the increased activity of NF-kappaB. FFR also showed significantly increased CD68- positive macrophages in the aortic wall. After treatment with felodipine, SBP, serum insulin, and the homeostasis model assessment decreased significantly. In addition to reducing ICAM-1 and VCAM-1, felodipine decreased macrophages in the aortic wall. EMSA revealed that felodipine inhibited NF-kappaB activation in FFR. CONCLUSION Felodipine inhibited vessel wall inflammation. The inhibition of NF-kappaB may be involved in the modulation of vascular inflammatory response by CCB in metabolic syndrome.
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Affiliation(s)
- Hong-wei Tan
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Ji-nan 250012, China
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Lee J. Nitric oxide in the kidney : its physiological role and pathophysiological implications. Electrolyte Blood Press 2008; 6:27-34. [PMID: 24459519 PMCID: PMC3894485 DOI: 10.5049/ebp.2008.6.1.27] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Accepted: 02/01/2008] [Indexed: 12/02/2022] Open
Abstract
Nitric oxide has been implicated in many physiologic processes that influence both acute and long-term control of kidney function. Its net effect in the kidney is to promote natriuresis and diuresis, contributing to adaptation to variations of dietary salt intake and maintenance of normal blood pressure. A pretreatment with nitric oxide donors or L-arginine may prevent the ischemic acute renal injury. In chronic kidney diseases, the systolic blood pressure is correlated with the plasma level of asymmetric dimethylarginine, an endogenous inhibitor of nitric oxide synthase. A reduced production and biological action of nitric oxide is associated with an elevation of arterial pressure, and conversely, an exaggerated activity may represent a compensatory mechanism to mitigate the hypertension.
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Affiliation(s)
- Jongun Lee
- Department of Physiology, Chonnam National University Medical School, Gwangju, Korea
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Affiliation(s)
- Fred G Silva
- The United States and Canadian Academy of Pathology and the Medical College of Georgia, Emory University, 3643 Walton Way Extension, Building 6, Augusta, GA 30909, USA.
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Yanes LL, Romero DG, Iles JW, Iliescu R, Gomez-Sanchez C, Reckelhoff JF. Sexual dimorphism in the renin-angiotensin system in aging spontaneously hypertensive rats. Am J Physiol Regul Integr Comp Physiol 2006; 291:R383-90. [PMID: 16914423 DOI: 10.1152/ajpregu.00510.2005] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In young adult spontaneously hypertensive rats (SHR), mean arterial pressure (MAP) is higher in males than in females and inhibition of the renin-angiotensin system (RAS) eliminates this sex difference. After cessation of estrous cycling in female SHR, MAP is similar to that in male SHR. The purpose of this study was to determine the role of the RAS in maintenance of hypertension in aging male and female SHR. At 16 mo of age, MAP was similar in male and female SHR (183+/-5 vs. 193+/-8 mmHg), and chronic losartan (40 mg.kg-1.day-1 po for 3 wk) reduced MAP by 52% (to 90+/-8 mmHg, P<0.05 vs. control) in males and 37% (to 123+/-11 mmHg, P<0.05 vs. control) in females (P<0.05, females vs. males). The effect of losartan on angiotensin type 1 (AT1) receptor blockade was similar: MAP responses to acute doses of ANG II (62.5-250 ng/kg) were blocked to a similar extent in losartan-treated males and females. F2-isoprostane excretion was reduced with losartan more in males than in females. There were no sex differences in plasma renin activity, plasma angiotensinogen or ANG II, or renal expression of AT1 receptors, angiotensin-converting enzyme, or renin. However, renal angiotensinogen mRNA and protein expression was higher in old males than females, whereas renal ANG II was higher in old females than males. The data show that, in aging SHR, when blood pressures are similar, there remains a sexual dimorphism in the response to AT1 receptor antagonism, and the differences may involve sex differences in mechanisms responsible for oxidative stress with aging.
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Affiliation(s)
- Licy L Yanes
- Department of Physiology and Biophysics, University of Mississippi Medical Center, 2500 N. State St., Jackson, MS 39216-4505, USA
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Li C, Sun BK, Lim SW, Song JC, Kang SW, Kim YS, Kang DH, Cha JH, Kim J, Yang CW. Combined Effects of Losartan and Pravastatin on Interstitial Inflammation and Fibrosis in Chronic Cyclosporine-Induced Nephropathy. Transplantation 2005; 79:1522-9. [PMID: 15940041 DOI: 10.1097/01.tp.0000155305.49439.4c] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND Statins and angiotensin II type I receptor blockers have synergistic effects on vascular smooth-muscle-cell proliferation and the progression of renal diseases. We evaluated whether combined treatment with losartan (LSRT) and pravastatin (PRVT) affords superior protection compared with their respective monotherapies in treating chronic cyclosporine (CsA)-induced nephropathy in rats. METHODS Rats maintained on a low salt diet were given vehicle, CsA (15 mg/kg), CsA and LSRT (10 mg/kg), CsA and PRVT (5 mg/kg), or a combination of CsA, LSRT, and PRVT for 28 days. Basic parameters (renal function, systolic blood pressure, serum high-sensitivity C-reactive protein [hs-CRP], and lipid profiles), histopathology (arteriolopathy, tubulointerstitial fibrosis, and inflammatory cell infiltration), and inflammatory and fibrotic factors (intrarenal CRP, angiotensin II, osteopontin, and transforming growth factor [TGF]-beta1) were studied. RESULTS LSRT or PRVT treatment significantly attenuated the histopathologic changes induced by CsA, and combined treatment with LSRT and PRVT further decreased these parameters compared with giving each drug alone. Increased levels of angiotensin II, intrarenal CRP, osteopontin, and TGF-beta1 in CsA-treated rat kidney were reduced by treatment with either LSRT or PRVT and were further decreased by the combination of the two drugs. There were no significant differences in systolic blood pressure or serum lipid parameters between groups. CONCLUSIONS Combined treatment with LSRT and PRVT provided synergistic effects in attenuating inflammatory and fibrotic processes in a rat model of chronic CsA-induced nephropathy, and this effect was independent of their hypolipidemic and hypotensive actions.
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Affiliation(s)
- Can Li
- Department of Internal Medicine, KangNam St. Mary's Hospital, The Catholic University of Korea, Seoul 137-040, Korea
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Gil FZ, Lucas SRR, Gomes GN, Cavanal MDF, Coimbra TM. Effects of intrauterine food restriction and long-term dietary supplementation with L-arginine on age-related changes in renal function and structure of rats. Pediatr Res 2005; 57:724-31. [PMID: 15774822 DOI: 10.1203/01.pdr.0000159514.06939.7e] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We have previously demonstrated that restricting intrauterine food by 50% in 3-mo-old rats produced lower nephron numbers and early-onset hypertension, the latter being normalized by L-arginine administration. In 18-mo-old rats, such restriction increased glomerulosclerosis. In this study, we expanded our investigation, evaluating functional, morphologic, and immunohistochemical parameters in intrauterine-food-restricted 18-mo-old rats, either receiving L-arginine (RA18) or not (R18). Age-matched, non-food-restricted controls were assigned to similar groups with L-arginine (CA18) and without (C18). After weaning, L-arginine was given daily for 17 mo. No functional or morphologic changes were observed in C18 rats. The R18 rats developed early-onset hypertension, which persisted throughout the observation period, as well as significant proteinuria from 12 mo on. In RA18 rats, L-arginine decreased both blood pressure levels and proteinuria, and glomerular diameter was significantly smaller than in R18 rats (115.63 +/- 2.2 versus 134.8 +/- 1.0 mum, p < 0.05). However, in RA18 rats, glomerular filtration rate remained depressed. Although L-arginine prevented glomerulosclerosis (R18 = 14%, RA18 = 4%; p < 0.05), glomerular expression of fibronectin and desmin was still greater in RA18 rats than in controls. Our data show that, although L-arginine prevented hypertension and proteinuria, glomerular injury still occurred, suggesting that intrauterine food restriction may be one of the leading causes of impaired renal function in adult life.
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Affiliation(s)
- Frida Zaladek Gil
- Department of Physiology, Renal Physiology, and Metabolic Biology, UNIFESP-EPM, São Paulo, Brazil, 04023-900.
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Okano H, Masuda H, Ohkubo C. Decreased plasma levels of nitric oxide metabolites, angiotensin II, and aldosterone in spontaneously hypertensive rats exposed to 5 mT static magnetic field. Bioelectromagnetics 2005; 26:161-72. [PMID: 15768432 DOI: 10.1002/bem.20055] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Previously, we found that whole body exposure to static magnetic fields (SMF) at 10 mT (B(max)) and 25 mT (B(max)) for 2-9 weeks suppressed and delayed blood pressure (BP) elevation in young, stroke resistant, spontaneously hypertensive rats (SHR). In this study, we investigated the interrelated antipressor effects of lower field strengths and nitric oxide (NO) metabolites (NO(x) = NO(2)(-) + NO(3)(-)) in SHR. Seven-week-old male rats were exposed to two different ranges of SMF intensity, 0.3-1.0 mT or 1.5-5.0 mT, for 12 weeks. Three experimental groups of 20 animals each were examined: (1) no exposure with intraperitoneal (ip) saline injection (sham-exposed control); (2) 1 mT SMF exposure with ip saline injection (1 mT); (3) 5 mT SMF exposure with ip saline injection (5 mT). Arterial BP, heart rate (HR), skin blood flow (SBF), plasma NO metabolites (NO(x)), and plasma catecholamine levels were monitored. SMF at 5 mT, but not 1 mT, significantly suppressed and retarded the early stage development of hypertension for several weeks, compared with the age matched, unexposed (sham exposed) control. Exposure to 5 mT resulted in reduced plasma NO(x) concentrations together with lower levels of angiotensin II and aldosterone in SHR. These results suggest that SMF may suppress and delay BP elevation via the NO pathways and hormonal regulatory systems.
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Affiliation(s)
- Hideyuki Okano
- Department of Environmental Health, National Institute of Public Health, Tokyo 108-8638, Japan.
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Abstract
PURPOSE OF REVIEW To review the influence of antihypertensive therapy on the contribution of nitric oxide (NO) to renal perfusion in essential hypertension. RECENT FINDINGS The contribution of endothelium-derived NO to renal perfusion can be examined in detail by studying isolated glomerular arterioles and by immunohistochemical techniques. Only few functional studies in human arterial hypertension exist analysing the role of NO for renal perfusion and the change in renal NO bioavailability due to arterial hypertension and its modification by antihypertensive therapy. SUMMARY NO critically contributes to renal perfusion. There is evidence of reduced but also of unchanged NO bioavailability in the renal vasculature of patients with arterial hypertension both from protein expression and functional studies. In particular, drugs interacting with the renin-angiotensin-aldosterone system (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and aldosterone antagonists) and third-generation beta blockers are promising candidates to improve renal endothelial function. It is not yet clear whether these specific effects translate into prevention of nephrosclerosis.
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Affiliation(s)
- Christian Delles
- Department of Medicine IV, University of Erlangen-Nürnberg, Germany
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Zhan CD, Sindhu RK, Vaziri ND. Up-regulation of kidney NAD(P)H oxidase and calcineurin in SHR: Reversal by lifelong antioxidant supplementation. Kidney Int 2004; 65:219-27. [PMID: 14675053 DOI: 10.1111/j.1523-1755.2004.00372.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Spontaneously hypertensive rats (SHR) are born normotensive and develop hypertension (HTN) later in life (age 4 to 5 weeks). HTN in SHR is associated with and caused in part, by oxidative stress and renal interstitial inflammation. This study tested the hypothesis that lifelong antioxidant supplementation beginning at prenatal period may delay the onset and reduce the severity of HTN in SHR. The study further sought to explore the effect of diet modification on renal tissue NAD(P)H oxidase and calcineurin abundance. METHODS Pregnant SHR and their offspring were fed either an antioxidant-fortified diet (a chow containing alpha-tocopherol 5000 IU/kg, ascorbic acid 500 ppm, selenium 2.76 ppm, and zinc 350 ppm) or regular diet (alpha-tocopherol 40 IU/kg, selenium 0.2 ppm, and zinc 70 ppm). Animals were observed for 24 weeks. Wistar-Kyoto rats fed either a regular or antioxidant diet served as control. RESULTS Onset of HTN was delayed and severity of HTN was reduced in antioxidant-treated compared with untreated SHR. Markers of oxidative stress (i.e., plasma hydrogen peroxide, renal tissue malondialdehyde, and nitrotyrosine abundance) were elevated in untreated but not in antioxidant-treated SHR. gp91phox and p22phox subunits of NAD(P)H oxidase were markedly elevated in the renal cortex of untreated SHR and partially restored in the treated SHR. Similarly, renal calcineurin Aalpha and B subunits were elevated in untreated SHR and were partially restored in the treated SHR. Antioxidant therapy had no effect on the measured parameters in the WKY control. CONCLUSION Lifelong consumption of antioxidant-rich diet ameliorates HTN and oxidative stress in SHR. This is associated with the reduction of superoxide-generating enzyme, NAD(P)H oxidase, and immunoregulatory factor calcineurin. Antioxidant-rich diet appears to attenuate oxidative stress, not only by fortifying antioxidant defense capacity but also by lowering NAD(P)H oxidase, which is a major source of reactive oxygen species.
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Affiliation(s)
- Chang-De Zhan
- Division of Nephrology and Hypertension, Department of Medicine, University of California, Irvine, California, USA
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Heller J, Shiozawa T, Trebicka J, Hennenberg M, Schepke M, Neef M, Sauerbruch T. Acute haemodynamic effects of losartan in anaesthetized cirrhotic rats. Eur J Clin Invest 2003; 33:1006-12. [PMID: 14636305 DOI: 10.1046/j.1365-2362.2003.01251.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Portal hypertension in cirrhosis is the result of increased intrahepatic vascular resistance to portal outflow as well as increased portal tributary blood flow. The angiotensin II type 1 receptor antagonist losartan has been suggested as a portal pressure-lowering drug in patients with cirrhosis. AIM To investigate the systemic and splanchnic haemodynamic effects of different doses of losartan. METHODS In 35 anaesthetized rats with secondary biliary cirrhosis, 3, 10 or 30 mg of losartan kg(-1) or solvent were administered intravenously. Ten sham-operated rats served as controls. Mean arterial pressure and portal pressure were measured by catheters in the femoral artery or portal vein. Systemic and splanchnic haemodynamics and mesenterico-systemic shunt rate were determined by the coloured microsphere method. RESULTS Losartan reduced portal pressure (sham: 9.1 +/- 0.4. cirrhosis: 19.3 +/- 1.1, after 3 mg kg(-1) of losartan 16.4 +/- 0.4, after 10 mg kg(-1) of losartan 15.6 +/- 0.6, after 30 mg kg(-1) of losartan 14.9 +/- 0.6 mmHg) without reducing portal sinusoidal resistance. However, in cirrhotic rats it reduced portal tributary blood flow (sham: 4.3 +/- 0.6. cirrhosis: 8.6 +/- 1.4, after 3 mg kg(-1) of losartan 3.8 +/- 0.7, after 10 mg kg(-1) of losartan 4.7 +/- 0.5, after 30 mg kg(-1) of losartan 5.9 +/- 0.9 mmHg). This was owing either to an increase in splanchnic vascular resistance at the 3 mg kg(-1) dose or to a reduction in the splanchnic perfusion-pressure gradient secondary to a reduction in mean arterial pressure at the 10 and 30 mg kg(-1) doses (mean arterial pressure: sham: 109.7 +/- 4.8. cirrhosis: 109.4 +/- 2.8, after 3 mg kg(-1) of losartan 99.7 +/- 2.9, after 10 mg kg(-1) of losartan 89.9 +/- 3.4, after 30 mg kg(-1) of losartan 81.0 +/- 2.9 mmHg). CONCLUSIONS Low doses of losartan reduce portal hypertension by an increase in splanchnic vascular resistance without hypotensive side-effects on arterial pressure.
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Affiliation(s)
- J Heller
- Department of Internal Medicine I, University of Bonn, Bonn, Germany.
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