1
|
Yang P, Zhao X, Zhou L, Jin Y, Zheng X, Ouyang Y, Chen M, Zeng L, Chen S, Chen X, Tian Z. Protective effect of oral histidine on hypertension in Dahl salt-sensitive rats induced by high-salt diet. Life Sci 2021; 270:119134. [PMID: 33513395 DOI: 10.1016/j.lfs.2021.119134] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/15/2021] [Accepted: 01/15/2021] [Indexed: 01/11/2023]
Abstract
AIMS Salt-sensitive hypertension is a risk factor for cardiovascular disease. Previous studies have shown that insufficient arginine in the kidney caused by metabolic imbalance is an important factor in salt-sensitive hypertension. Whether the high nitrogen content of histidine can affect the balance of nitrogen metabolism in Dahl salt-sensitive (SS) rats. This article aimed to study the effects of oral histidine on salt-sensitive hypertension, kidney damage and metabolic patterns of high-salt diet in SS rats. MAIN METHODS Adult rats were divided into four groups, and blood pressure was measured using a non-invasive tail-cuff system. Gas chromatography-mass spectrometry analyzed metabolites in serum and kidney tissues. KEY FINDINGS High-salt diet significantly increased the blood pressure of rats and aggravated kidney damage. Of note, histidine can attenuate salt-sensitive hypertension and kidney damage by improving metabolic pattern, reducing Reactive Oxygen Species (ROS) and increasing nitric oxide levels in SS rats. SIGNIFICANCE These results suggest that histidine could be a potential adjuvant to prevent and control salt-sensitive hypertension.
Collapse
Affiliation(s)
- Pengfei Yang
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Xinrui Zhao
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Luxin Zhou
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yuexin Jin
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Xuewei Zheng
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yanan Ouyang
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Meng Chen
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Li Zeng
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Sa Chen
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Xiangbo Chen
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zhongmin Tian
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
| |
Collapse
|
2
|
Adejare A, Oloyo A, Anigbogu C, Jaja S. l-arginine Supplementation Increased Only Endothelium-Dependent Relaxation in Sprague-Dawley Rats Fed a High-Salt Diet by Enhancing Abdominal Aorta Endothelial Nitric Oxide Synthase Gene Expression. Clin Med Insights Cardiol 2020; 14:1179546820902843. [PMID: 32063725 PMCID: PMC6990607 DOI: 10.1177/1179546820902843] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 01/07/2020] [Indexed: 11/15/2022]
Abstract
Background Abnormal vascular reactivity and reduced expression of endothelial nitric oxide synthase (eNOS) gene are hallmark of salt-induced hypertension in rats. Although l-arginine is an established vasodilator, the mechanism by which it modulates vascular reactivity in salt-induced hypertension is not clearly understood. Objectives This study was designed to investigate the mechanism by which oral l-arginine supplementation modulates vascular reactivity and eNOS gene expression in Sprague-Dawley rats fed a high-salt diet. Methods Forty-eight weaned male Sprague-Dawley rats of weight range 90 to 110 g were randomly divided into 6 groups of 8 rats per group. Group I was fed normal rat chow ad libitum and served as the Normal Diet group. Group II was fed a diet that contained 8% NaCl. Groups III and IV took normal and high-salt diet, respectively, and then received oral l-arginine supplementation (100 mg/kg/day), while groups V and VI took normal and high-salt diet, respectively, and then were co-administered with both l-arginine and l-nitro-arginine methyl ester (L-NAME; 100 mg/kg/day and 40 mg/kg/day, respectively) orally. At the end of 12-week experimental period, the animals were sacrificed to assess vascular reactivity and gene expression level. Results Our results show that high-salt diet significantly reduced (P < .05) endothelium-dependent relaxation response to acetylcholine and qualitatively reduced eNOS gene expression in the abdominal aorta of the rats. However, l-arginine supplementation improved the impaired endothelium-dependent relaxation and nitric oxide level while ameliorating the reduced eNOS gene expressions. Conclusion This study suggests that oral supplementation of l-arginine enhances endothelial-dependent relaxation in rats fed a high-salt diet by ameliorating eNOS gene expression in the abdominal aorta of the rats.
Collapse
Affiliation(s)
- Abdullahi Adejare
- Department of Physiology, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Ahmed Oloyo
- Department of Physiology, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Chikodi Anigbogu
- Department of Physiology, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Smith Jaja
- Department of Physiology, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Lagos, Nigeria
| |
Collapse
|
3
|
NOMURA S, MONOBE M, EMA K, MAEDA-YAMAMOTO M, NESUMI A. Comparison of the Effects of Three Tea Cultivars ( Camellia sinensis L.) on Nitric Oxide Production and Aortic Soluble Guanylate Cyclase Expression in High-Salt Diet-Fed Spontaneously Hypertensive Rats. J Nutr Sci Vitaminol (Tokyo) 2017; 63:306-314. [DOI: 10.3177/jnsv.63.306] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Sachiko NOMURA
- Tea Research Division, Institute of Fruit Tree and Tea Science, National Agriculture and Food Research Organization (NARO)
| | - Manami MONOBE
- Tea Research Division, Institute of Fruit Tree and Tea Science, National Agriculture and Food Research Organization (NARO)
| | - Kaori EMA
- Tea Research Division, Institute of Fruit Tree and Tea Science, National Agriculture and Food Research Organization (NARO)
| | | | - Atsushi NESUMI
- Tea Research Division, Institute of Fruit Tree and Tea Science, National Agriculture and Food Research Organization (NARO)
| |
Collapse
|
4
|
Oshiro Junior JA, Paiva Abuçafy M, Berbel Manaia E, Lallo da Silva B, Chiari-Andréo BG, Aparecida Chiavacci L. Drug Delivery Systems Obtained from Silica Based Organic-Inorganic Hybrids. Polymers (Basel) 2016; 8:E91. [PMID: 30979199 DOI: 10.3390/polym8040091] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 03/08/2016] [Accepted: 03/10/2016] [Indexed: 11/29/2022] Open
Abstract
This is a review of hybrid materials based on silica as an inorganic phase used as drug delivery systems (DDS). Silica based DDS have shown effectivity when compared with traditional delivery systems. They present advantages such as: (a) ability to maintain the therapeutic range with minor variations; (b) prevention of local and systemic toxic effects; (c) plasma concentrations increase of substances with a short half-life; and (d) reduction of the number of daily doses, which may increase patient adherence to the treatment. These advantages occur due to the physical, chemical and optical properties of these materials. Therefore, we discuss the properties and characteristics of them and we present some applications, using different approaches of DDS to ensure therapeutic effectiveness and side effects reduction such as implantable biomaterial, film-forming materials, stimuli-responsive systems and others.
Collapse
|
5
|
Maruyama K, Kagota S, Van Vliet BN, Wakuda H, Shinozuka K. A maternal high salt diet disturbs cardiac and vascular function of offspring. Life Sci 2015; 136:42-51. [DOI: 10.1016/j.lfs.2015.06.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 06/08/2015] [Accepted: 06/27/2015] [Indexed: 01/06/2023]
|
6
|
Angelone T, Quintieri AM, Pasqua T, Filice E, Cantafio P, Scavello F, Rocca C, Mahata SK, Gattuso A, Cerra MC. The NO stimulator, Catestatin, improves the Frank-Starling response in normotensive and hypertensive rat hearts. Nitric Oxide 2015; 50:10-19. [PMID: 26241941 DOI: 10.1016/j.niox.2015.07.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/08/2015] [Accepted: 07/29/2015] [Indexed: 10/23/2022]
Abstract
The myocardial response to mechanical stretch (Frank-Starling law) is an important physiological cardiac determinant. Modulated by many endogenous substances, it is impaired in the presence of cardiovascular pathologies and during senescence. Catestatin (CST:hCgA352-372), a 21-amino-acid derivate of Chromogranin A (CgA), displays hypotensive/vasodilatory properties and counteracts excessive systemic and/or intra-cardiac excitatory stimuli (e.g., catecholamines and endothelin-1). CST, produced also by the myocardium, affects the heart by modulating inotropy, lusitropy and the coronary tone through a Nitric Oxide (NO)-dependent mechanism. This study evaluated the putative influence elicited by CST on the Frank-Starling response of normotensive Wistar-Kyoto (WKY) and hypertensive (SHR) hearts by using isolated and Langendorff perfused cardiac preparations. Functional changes were evaluated on aged (18-month-old) WKY rats and SHR which mimic human chronic heart failure (HF). Comparison to WKY rats, SHR showed a reduced Frank-Starling response. In both rat strains, CST administration improved myocardial mechanical response to increased end-diastolic pressures. This effect was mediated by EE/IP3K/NOS/NO/cGMP/PKG, as revealed by specific inhibitors. CST-dependent positive Frank-Starling response is paralleled by an increment in protein S-Nitrosylation. Our data suggested CST as a NO-dependent physiological modulator of the stretch-induced intrinsic regulation of the heart. This may be of particular importance in the aged hypertrophic heart, whose function is impaired because of a reduced systolic performance accompanied by delayed relaxation and increased diastolic stiffness.
Collapse
Affiliation(s)
- T Angelone
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy; National Institute of Cardiovascular Research, Bologna, Italy
| | - A M Quintieri
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy
| | - T Pasqua
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy
| | - E Filice
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy
| | - P Cantafio
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy
| | - F Scavello
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy
| | - C Rocca
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy
| | - S K Mahata
- Department of Medicine, University of California & VA San Diego Healthcare System, San Diego, USA
| | - A Gattuso
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy.
| | - M C Cerra
- Dept of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy; National Institute of Cardiovascular Research, Bologna, Italy.
| |
Collapse
|
7
|
Yuan TY, Yan Y, Wu YJ, Xu XN, Li L, Jiao XZ, Xie P, Fang LH, Du GH. Vasodilatory effect of a novel Rho-kinase inhibitor, DL0805-2, on the rat mesenteric artery and its potential mechanisms. Cardiovasc Drugs Ther 2014; 28:415-24. [PMID: 25086815 DOI: 10.1007/s10557-014-6544-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PURPOSE In the present study, we investigated the vasodilatory effect of a novel scaffold Rho-kinase inhibitor, DL0805-2, on isolated rat arterial rings including mesenteric, ventral tail, and renal arteries. We also examined the potential mechanisms of its vasodilatory action using mesenteric artery rings. METHODS A DMT multiwire myograph system was used to test the tension of isolated small arteries. Several drugs were employed to verify the underlying mechanisms. RESULTS DL0805-2 (10(-7)-10(-4) M) inhibited KCl (60 mM)-induced vasoconstriction in three types of small artery rings (pEC50: 5.84 ± 0.03, 5.39 ± 0.03, and 5.67 ± 0.02 for mesenteric, renal, and ventral tail artery rings, respectively). Pre-incubation with DL0805-2 (1, 3, or 10 μM) attenuated KCl (10-60 mM) and angiotensin II (AngII; 10(-6) M)-induced vasoconstriction in mesenteric artery rings. The relaxant effect on the rat mesenteric artery was partially endothelium-dependent (pEC50: 6.02 ± 0.05 for endothelium-intact and 5.72 ± 0.06 for endothelium-denuded). The influx and release of Ca(2+) were inhibited by DL0805-2. In addition, the increased phosphorylation levels of myosin light chain (MLC) and myosin-binding subunit of myosin phosphatase (MYPT1) induced by AngII were blocked by DL0805-2. However, DL0805-2 had little effect on K(+) channels. CONCLUSIONS The present results demonstrate that DL0805-2 has a vasorelaxant effect on isolated rat small arteries and may exert its action through the endothelium, Ca(2+) channels, and the Rho/ROCK pathway.
Collapse
|
8
|
Sarkar A, Karmakar S, Bhattacharyya S, Purkait K, Mukherjee A. Nitric oxide release by N-(2-chloroethyl)-N-nitrosoureas: a rarely discussed mechanistic path towards their anticancer activity. RSC Adv 2015. [DOI: 10.1039/c4ra11137k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Our work shows that NO release is a feasible pathway of action for aromatic and heterocyclic N-(2-chloroethyl)-N-nitrosoureas and faster NO release may not lead to higher cytotoxicity.
Collapse
Affiliation(s)
- Amrita Sarkar
- Department of Chemical Sciences
- Indian Institute of Science Education & Research Kolkata
- Nadia
- India
| | - Subhendu Karmakar
- Department of Chemical Sciences
- Indian Institute of Science Education & Research Kolkata
- Nadia
- India
| | - Sudipta Bhattacharyya
- Department of Chemical Sciences
- Indian Institute of Science Education & Research Kolkata
- Nadia
- India
| | - Kallol Purkait
- Department of Chemical Sciences
- Indian Institute of Science Education & Research Kolkata
- Nadia
- India
| | - Arindam Mukherjee
- Department of Chemical Sciences
- Indian Institute of Science Education & Research Kolkata
- Nadia
- India
| |
Collapse
|
9
|
Abstract
The present review first summarizes the complex chain of events, in endothelial and vascular smooth muscle cells, that leads to endothelium-dependent relaxations (vasodilatations) due to the generation of nitric oxide (NO) by endothelial nitric oxide synthase (eNOS) and how therapeutic interventions may improve the bioavailability of NO and thus prevent/cure endothelial dysfunction. Then, the role of other endothelium-derived mediators (endothelium-derived hyperpolarizing (EDHF) and contracting (EDCF) factors, endothelin-1) and signals (myoendothelial coupling) is summarized also, with special emphasis on their interaction(s) with the NO pathway, which make the latter not only a major mediator but also a key regulator of endothelium-dependent responses.
Collapse
|
10
|
Kassan M, Galán M, Partyka M, Saifudeen Z, Henrion D, Trebak M, Matrougui K. Endoplasmic reticulum stress is involved in cardiac damage and vascular endothelial dysfunction in hypertensive mice. Arterioscler Thromb Vasc Biol 2012; 32:1652-61. [PMID: 22539597 DOI: 10.1161/atvbaha.112.249318] [Citation(s) in RCA: 166] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Cardiac damage and vascular dysfunction are major causes of morbidity and mortality in hypertension. In the present study, we explored the beneficial therapeutic effect of endoplasmic reticulum (ER) stress inhibition on cardiac damage and vascular dysfunction in hypertension. METHODS AND RESULTS Mice were infused with angiotensin II (400 ng/kg per minute) with or without ER stress inhibitors (taurine-conjugated ursodeoxycholic acid and 4-phenylbutyric acid) for 2 weeks. Mice infused with angiotensin II displayed an increase in blood pressure, cardiac hypertrophy and fibrosis associated with enhanced collagen I content, transforming growth factor-β1 (TGF-β1) activity, and ER stress markers, which were blunted after ER stress inhibition. Hypertension induced ER stress in aorta and mesenteric resistance arteries (MRA), enhanced TGF-β1 activity in aorta but not in MRA, and reduced endothelial NO synthase phosphorylation and endothelium-dependent relaxation (EDR) in aorta and MRA. The inhibition of ER stress significantly reduced TGF-β1 activity, enhanced endothelial NO synthase phosphorylation, and improved EDR. The inhibition of TGF-β1 pathway improved EDR in aorta but not in MRA, whereas the reduction in reactive oxygen species levels ameliorated EDR in MRA only. Infusion of tunicamycin in control mice induced ER stress in aorta and MRA, and reduced EDR by a TGF-β1-dependent mechanism in aorta and reactive oxygen species-dependent mechanism in MRA. CONCLUSIONS ER stress inhibition reduces cardiac damage and improves vascular function in hypertension. Therefore, ER stress could be a potential target for cardiovascular diseases.
Collapse
Affiliation(s)
- Modar Kassan
- Department of Physiology, Hypertension and Renal Center of Excellence, Tulane University, New Orleans, LA 70112, USA
| | | | | | | | | | | | | |
Collapse
|
11
|
Saraiva J, Marotta-Oliveira SS, Cicillini SA, Eloy JDO, Marchetti JM. Nanocarriers for nitric oxide delivery. J Drug Deliv 2011; 2011:936438. [PMID: 21869934 PMCID: PMC3159988 DOI: 10.1155/2011/936438] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 05/13/2011] [Indexed: 12/16/2022]
Abstract
Nitric oxide (NO) is a promising pharmaceutical agent that has vasodilative, antibacterial, and tumoricidal effects. To study the complex and wide-ranging roles of NO and to facilitate its therapeutic use, a great number of synthetic compounds (e.g., nitrosothiols, nitrosohydroxyamines, N-diazeniumdiolates, and nitrosyl metal complexes) have been developed to chemically stabilize and release NO in a controlled manner. Although NO is currently being exploited in many biomedical applications, its use is limited by several factors, including a short half-life, instability during storage, and potential toxicity. Additionally, efficient methods of both localized and systemic in vivo delivery and dose control are needed. One strategy for addressing these limitations and thus increasing the utility of NO donors is based on nanotechnology.
Collapse
Affiliation(s)
- Juliana Saraiva
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14010-903 Ribeirão Preto, SP, Brazil
| | - Samantha S. Marotta-Oliveira
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14010-903 Ribeirão Preto, SP, Brazil
| | - Simone Aparecida Cicillini
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14010-903 Ribeirão Preto, SP, Brazil
| | - Josimar de Oliveira Eloy
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14010-903 Ribeirão Preto, SP, Brazil
| | - Juliana Maldonado Marchetti
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14010-903 Ribeirão Preto, SP, Brazil
| |
Collapse
|
12
|
|
13
|
|
14
|
Abstract
BACKGROUND The purpose of this study was to evaluate the relationship between erectile dysfunction (ED) and non-dipper pattern in hypertensive patients. METHODS A total of 750 consecutive patients with essential hypertension, who had been evaluated with ambulatory BP monitoring, were screened for this study. One hundred and thirty-two male patients (age range 28-54 years) who had fulfilled the inclusion and exclusion criteria were included in the final analysis. Dipper and non-dipper patterns were detected and sexual function was assessed by the self-administered questionnaire of the International Index of Erectile Function (IIEF). RESULTS There was no significant difference between the two groups regarding the number of medications taken and the proportion of each class of antihypertensive medications. Mean age, body mass index, lipid profiles, rate of smoking were similar between the two groups. IIEF score was significantly higher in non-dippers than dippers (p= 0.009). Non-dipping was also found to be an independent determinant for ED. CONCLUSION The result of the present study further suggests that non-dipping is a risk indicator for early deterioration of erectile function in hypertensive patients.
Collapse
Affiliation(s)
- Ismail Erden
- Department of Cardiology, Düzce Medical School, Duzce University, Konuralp Düzce, Turkey.
| | | | | | | | | | | |
Collapse
|
15
|
Sud N, Black SM. Endothelin-1 impairs nitric oxide signaling in endothelial cells through a protein kinase Cdelta-dependent activation of STAT3 and decreased endothelial nitric oxide synthase expression. DNA Cell Biol 2009; 28:543-53. [PMID: 19754268 DOI: 10.1089/dna.2009.0865] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In an ovine model of persistent pulmonary hypertension of the newborn (PPHN), endothelin-1 (ET-1) expression is increased, while endothelial nitric oxide synthase (eNOS) expression is decreased. However, the molecular mechanisms by which ET-1 attenuates eNOS expression in endothelial cells are not completely understood. Thus, the goal of this study was to determine if the overexpression of ET-1 decreases eNOS expression in pulmonary arterial endothelial cells isolated from fetal lambs. To increase the ET-1 expression, cells were transfected with a plasmid coding for Prepro-ET-1, a precursor of ET-1. After overexpression of Prepro-ET-1, ET-1 levels in the culture medium were significantly increased (control = 805.3 +/- 69.8; Prepro-ET-1 overexpression = 1351 +/- 127.9). eNOS promoter activity, protein levels, and NO generation were all significantly decreased by the overexpression of Prepro-ET-1. The decrease in transcription correlated with increased activity of protein kinase Cdelta (PKCdelta) and STAT3. Further, DNA binding activity of STAT3 was also increased by Prepro-ET-1 overexpression. The increase in STAT3 activity and decrease in eNOS promoter activity were inhibited by the overexpression of dominant negative mutants of PKCdelta or STAT3. Further, a 2 bp mutation in the STAT3 binding site in the eNOS promoter inhibited STAT3 binding and led to enhanced promoter activity in the presence of Prepro-ET-1 overexpression. In conclusion, ET-1 secretion is increased by Prepro-ET-1 overexpression. This results in activation of PKCdelta, which phosphorylates STAT3, increasing its binding to the eNOS promoter. This in turn decreases eNOS promoter activity, protein levels, and NO production. Thus, ET-1 can reduce eNOS expression and NO generation in fetal pulmonary artery endothelial cells through PKCdelta-mediated activation of STAT3.
Collapse
Affiliation(s)
- Neetu Sud
- Program in Pulmonary Vascular Disease, Vascular Biology Center, Medical College of Georgia, Augusta, Georgia 30912, USA
| | | |
Collapse
|
16
|
Banegas I, Prieto I, Vives F, Alba F, de Gasparo M, Duran R, Luna JDD, Segarra AB, Hermoso F, Ramírez M. Asymmetrical response of aminopeptidase A and nitric oxide in plasma of normotensive and hypertensive rats with experimental hemiparkinsonism. Neuropharmacology 2009; 56:573-9. [DOI: 10.1016/j.neuropharm.2008.10.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 10/25/2008] [Accepted: 10/28/2008] [Indexed: 11/30/2022]
|
17
|
Abstract
BACKGROUND The effect of salt reduction on vascular function, assessed by brachial artery flow-mediated dilatation (FMD), is unknown. OBJECTIVE Our aim was to compare the effects of a low-salt (LS; 50 mmol Na/d) diet with those of a usual-salt (US; 150 mmol Na/d) diet on FMD. DESIGN This was a randomized crossover design in which 29 overweight and obese normotensive men and women followed an LS diet and a US diet for 2 wk. Both diets had similar potassium and saturated fat contents and were designed to ensure weight stability. After each intervention, FMD, pulse wave velocity, augmentation index, and blood pressure were measured. RESULTS FMD was significantly greater (P = 0.001) with the LS diet (4.89 +/- 2.42%) than with the US diet (3.37 +/- 2.10%), systolic blood pressure was significantly (P = 0.02) lower with the LS diet (112 +/- 11 mm Hg) than with the US diet (117 +/- 13 mm Hg), and 24-h sodium excretion was significantly lower (P = 0.0001) with the LS diet (64.1 +/- 41.3 mmol) than with the US diet (156.3 +/- 56.7 mmol). There was no correlation between change in FMD and change in 24-h sodium excretion or change in blood pressure. No significant changes in augmentation index or pulse wave velocity were observed. CONCLUSIONS Salt reduction improves endothelium-dependant vasodilation in normotensive subjects independently of the changes in measured resting clinic blood pressure. These findings suggest additional cardioprotective effects of salt reduction beyond blood pressure reduction. The trial is registered with the Australian and New Zealand Clinical Trials Registry (unique identifier: ANZCTR12607000381482; http://www.anzctr.org.au/trial_view.aspx?ID=82159).
Collapse
|
18
|
Abstract
In many forms of erectile dysfunction (ED), cardiovascular risk factors, in particular arterial hypertension, seem to be extremely common. While causes for ED are related to a broad spectrum of diseases, a generalized vascular process seems to be the underlying mechanism in many patients, which in a large portion of clinical cases involves endothelial dysfunction, ie, inadequate vasodilation in response to endothelium-dependent stimuli, both in the systemic vasculature and the penile arteries. Due to this close association of cardiovascular disease and ED, patients with ED should be evaluated as to whether they may suffer from cardiovascular risk factors including hypertension, cardiovascular disease or silent myocardial ischemia. On the other hand, cardiovascular patients, seeking treatment of ED, must be evaluated in order to decide whether treatment of ED or sexual activity can be recommended without significantly increased cardiac risk. The guideline from the first and second Princeton Consensus Conference may be applied in this context. While consequent treatment of cardiovascular risk factors should be accomplished in these patients, many antihypertensive drugs may worsen sexual function as a drug specific side-effect. Importantly, effective treatment for arterial hypertension should not be discontinued as hypertension itself may contribute to altered sexual functioning; to the contrary, alternative antihypertensive regimes should be administered with individually tailored drug regimes with minimal side-effects on sexual function. When phosphodiesterase-5 inhibitors, such as sildenafil, tadalafil and vardenafil, are prescribed to hypertensive patients on antihypertensive drugs, these combinations of antihypertensive drugs and phosphodiesterase 5 are usually well tolerated, provided there is a baseline blood pressure of at least 90/60 mmHg. However, there are two exceptions: nitric oxide donors and α-adrenoceptor blockers. Any drug serving as a nitric oxide donor (nitrates) is absolutely contraindicated in combination with phosphodiesterase 5 inhibitors, due to significant, potentially life threatening hypotension. Also, α-adrenoceptor blockers, such as doxazosin, terazosin and tamsulosin, should only be combined with phosphodiesterase 5 inhibitors with special caution and close monitoring of blood pressure.
Collapse
Affiliation(s)
- Thorsten Reffelmann
- University of Southern California, The Heart Institute, Good Samaritan Hospital, Division of Cardiovascular Medicine, Keck School of Medicine, Los Angeles, CA 90017-2395, USA
| | | |
Collapse
|
19
|
Kagota S, Kubota Y, Nejime N, Nakamura K, Kunitomo M, Shinozuka K. Impaired effect of salt loading on nitric oxide-mediated relaxation in aortas from stroke-prone spontaneously hypertensive rats. Clin Exp Pharmacol Physiol 2007; 34:48-54. [PMID: 17201735 DOI: 10.1111/j.1440-1681.2007.04532.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
1. The present study was designed to characterize the effects of salt on vasorelaxation via the nitric oxide (NO)/cGMP pathway in stroke-prone spontaneously hypertensive rats (SHRSP), which are highly salt sensitive. 2. Male 8-week-old SHRSP were given 1% NaCl solution as drinking water for 4 weeks, whereas control animals were given water only. 3. In aortic rings from salt-loaded SHRSP, relaxations in response to acetylcholine and sodium nitroprusside were significantly impaired compared with those in the control. In the presence of zaprinast, a cGMP-specific cyclic nucleotide phosphodiesterase (PDE)-5 inhibitor, the cGMP levels induced by these drugs were significantly reduced by salt loading, but remained unchanged in the absence of zaprinast. The protein levels of endothelial NO synthase, soluble guanylate cyclase (sGC) and cGMP-dependent protein kinase (PKG) remained unchanged with salt loading, but those of PDE-5 decreased significantly and those of phosphorylated PKG tended to decrease, although the change was not statistically significant. Salt loading significantly impaired the relaxation in response to 8-bromo-cGMP. 4. These results indicate that, in aortas from SHRSP, salt loading causes impairment of relaxation in response to NO, which may be due to a decrease in cGMP production by sGC and impairment of the relaxation pathway downstream of cGMP, which, in turn, probably causes a decrease in PKG activity. Reduced PDE-5 protein expression may act, in part, as a compensatory response to impairment of cGMP-mediated relaxation.
Collapse
Affiliation(s)
- Satomi Kagota
- Department of Pharmacology, School of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan.
| | | | | | | | | | | |
Collapse
|
20
|
Acosta TJ, Yoshioka S, Komiyama J, Lee SH, Grazul-Bilska AT, Skarzynski DJ, Okuda K. Effects of Storage and Passage of Bovine Luteal Endothelial Cells on Endothelin-1 and Prostaglandin F2.ALPHA. Production. J Reprod Dev 2007; 53:473-80. [PMID: 17229995 DOI: 10.1262/jrd.18142] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To establish a storage system for isolated bovine luteal endothelial cells (LECs), we investigated the basal and tumor necrosis factor (TNF) alpha-stimulated production of endothelin-1 (ET-1) and prostaglandin (PG) F2alpha in unfrozen and frozen-thawed LECs until passage 10. LECs were obtained from developing corpora lutea (CL; days 5-7 of the estrous cycle) using enzymatic digestion and magnetic beads coated with lectin BS-1. The LECs were frozen at -80 C or further cultured and/or passaged until passage 10 in DMEM/Ham's F-12 supplemented with 10% calf serum. The hormonal productions of unfrozen and frozen/thawed LECs were compared through passages 2-10. When both the unfrozen and frozen/thawed cells reached confluence, the culture medium was replaced with fresh medium containing 0.1% bovine serum albumin (BSA), and the cells were incubated with TNFalpha (50 ng/ml) for 12 h. The basal productions of ET-1 and PGF2alpha by the unfrozen and frozen/thawed LECs were similar at passage 2. The basal production of PGF2alpha by LECs was not altered by passage and storage at -80 C, whereas the basal production of ET-1 decreased from passage 2 and 3 to passage 4 in the unfrozen LECs and from passage 2 to passage 3 in the frozen/thawed LECs. However, production of ET-1 by the unfrozen and frozen/thawed LECs was similar between passages 4-10 and passages 3-10, respectively. Exposure of LECs to TNFalpha increased (P<0.05) ET-1 and PGF2alpha production by the unfrozen and frozen-thawed LECs in all passages examined. Thus, LECs obtained from developing CLs and stored until passage 10 can be used for study of the physiology of LECs in vitro.
Collapse
Affiliation(s)
- Tomas J Acosta
- Laboratory of Reproductive Endocrinology, Graduate School of Natural Science and Technology, Okayama University, Japan
| | | | | | | | | | | | | |
Collapse
|
21
|
Abstract
UNLABELLED Stress-induced vascular adaptive response in SHR was investigated, focusing on the endothelium. Noradrenaline responses were studied in intact and denuded aortas from 6-week-old (prehypertensive) and 14-week-old (hypertensive) SHR and age-matched Wistar rats submitted or not to acute stress (20-min swimming and 1-h immobilization 25 min apart), preceded or not by chronic stress (2 sessions 2 days apart of 1-h day immobilization for 5-consecutive days). Stress did not alter the reactivity of denuded aorta. Moreover, no alteration in the EC50 values was observed after stress exposure. In intact aortas, acute stress-induced hyporeactivity to noradrenaline similar between strains at both age. Chronic stress potentiated this adaptive response in 6- and 14-week-old Wistar but not in 6-week-old SHR, and did not alter the reactivity of 14-week-old SHR. Maximum response (g) in intact aortas [6-week-old: Wistar 3.25+/-0.12, Wistar/acute 1.95+/-0.12*, Wistar/chronic 1.36+/-0.21*(+), SHR 1.75+/-0.11, SHR/acute 0.88+/-0.08*, SHR/chronic 0.85+/-0.05*; 14-week-old: Wistar 3.83+/-0.13, Wistar/acute 2.72+/-0.13*, Wistar/chronic 1.91+/-0.19*(+), SHR 4.03+/-0.17, SHR/acute 2.26+/-0.12*, SHR/chronic 4.10+/-0.23; inside the same strain: *P < 0.05 relate to non-stressed rat, +P < 0.05 related to acute stressed rat; n = 6-18]. Independent of age and strain, L-NAME and endothelium removal abolished the stress-induced aorta hyporeactivity. CONCLUSION The vascular adaptive response to stress is impaired in SHR, independently of the hypertensive state. Moreover, this vascular adaptive response is characterized by endothelial nitric oxide-system hyperactivity in both strains.
Collapse
Affiliation(s)
- Sandra Cordellini
- Department of Pharmacology, Institute of Biosciences, University Estadual Paulista, São Paulo, Brazil.
| | | | | |
Collapse
|
22
|
Tamara P, Djurdjica J, Z. M, Nevena M, M. S. The effects of endothelin and L-NAME on plasma uric acid and urea concentration in Wistar rats. ACTA VET-BEOGRAD 2006; 56:181-189. [DOI: 10.2298/avb0603181p] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|
23
|
López-Hernández FJ, López-Novoa JM. The lord of the ring: mandatory role of the kidney in drug therapy of hypertension. Pharmacol Ther 2005; 111:53-80. [PMID: 16154201 DOI: 10.1016/j.pharmthera.2005.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Accepted: 08/01/2005] [Indexed: 12/21/2022]
Abstract
Strong evidence supports the idea that total peripheral resistance (TPR) is increased in all forms of human and experimental hypertension. Although the etiological participation of TPR in the origin and long-term maintenance of hypertension has been extensively debated, it now seems clear that the renal, nonadaptive, infinite gain-working, pressure-sensitive natriuresis and diuresis is the main mechanism of blood pressure control in the long term. The tissue, cellular, biochemical, and genetic sensors and executors of this process have not been fully identified yet, but the role of the renal medulla has gained growing attention as the physiopathological scenario in which the key regulatory elements reside. Specifically, the functionality of the renomedullary vasculature seems to be highly responsible for blood pressure control. The vasculature of the renal medulla becomes a new and more specific target for the therapeutic intervention of hypertension. Recent data on the effect of baroreceptor-controlled renal sympathetic activity on the long-term regulation of blood pressure are integrated. The renomedullary effects of the main antihypertensive drugs are discussed, and new perspectives for the therapeutic intervention of hypertension are outlined. Comparison of the genetic program of the renal medulla before and after the development of hypertension in spontaneously hypertensive and experimentally induced animal models might provide a mechanism for identifying the key genes that become activated or suppressed in the development of high blood pressure. These genes, their encoded proteins, or other elements related to their signalling and genetic pathways might serve as new and more specific targets for the pharmacological treatment of abnormally elevated blood pressure. Besides, proteins specifically located to the luminal side of the renomedullary vascular endothelium may serve as potential targets for site-directed drug and gene therapy.
Collapse
Affiliation(s)
- Francisco J López-Hernández
- Unidad de Investigación, Hospital Universitario de Salamanca, Paseo de San Vicente, 58-182, 37007 Salamanca, Spain.
| | | |
Collapse
|
24
|
Schäfer A, Widder J, Eigenthaler M, Ertl G, Bauersachs J. Reduced basal nitric oxide bioavailability and platelet activation in young spontaneously hypertensive rats. Biochem Pharmacol 2004; 67:2273-9. [PMID: 15163558 DOI: 10.1016/j.bcp.2004.02.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2004] [Accepted: 02/19/2004] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To investigate the role of basal nitric oxide (NO) bioavailability for platelet activation in young spontaneously hypertensive rats before onset of hypertension. Phosphorylation of the vasodilator-stimulated phosphoprotein (VASP) in platelets was used as a sensitive monitor of in vivo NO bioavailability. METHODS AND RESULTS Whole blood samples were taken from 10-week-old Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). In vivo surface-expression of P-selectin and platelet-binding of fibrinogen were assessed by flow cytometry. Platelet VASP-phosphorylation at its serine 239 (Ser239) and serine 157 (Ser157) residues was assessed using specific antibodies to determine NO bioavailability in vivo, and compared with endothelial vasomotor function. The increment in vascular tone following inhibition of NO-synthase in slightly preconstricted aortic rings was reduced indicating less NO formation under physiological stimulation (WKY 71.1+/-4.1%; SHR 57.8+/-2.4%, P<0.05). In vivo platelet VASP-phosphorylation was significantly reduced at both phosphorylation sites in SHR (mean fluorescence for Ser239: WKY: 15.2+/-0.6; SHR: 11.7+/-0.5, P<0.01; Ser157: WKY: 53.0+/-3.0; SHR: 35.0+/-3.5, P<0.05). Surface-expression of P-selectin and membrane-bound fibrinogen were significantly enhanced in SHR compared with WKY (P-selectin: WKY: 23.2+/-3.4; SHR 58.3+/-7.9, P<0.001; platelet-bound fibrinogen: WKY: 8.6+/-0.5; SHR: 13.5+/-1.1, P<0.001). In vitro preincubation of platelets with the NO donor sodium nitroprusside normalized platelet surface-expression of P-selectin in SHR. CONCLUSION Using VASP-phosphorylation as a sensitive monitor of in vivo NO bioavailability, these data provide evidence that reduced vascular NO formation in vivo contributes to increased platelet activation in young SHR.
Collapse
Affiliation(s)
- Andreas Schäfer
- Medizinische Klinik der Julius-Maximilians-Universität, Würzburg, Germany.
| | | | | | | | | |
Collapse
|
25
|
Sofola O, Yakubu M, Igbo I, Newaz M, Oyekan A. High salt diet modulates cAMP- and nitric oxide-mediated relaxation responses to isoproterenol in the rat aorta. Eur J Pharmacol 2003; 474:241-7. [PMID: 12921869 DOI: 10.1016/s0014-2999(03)02011-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This study tested the hypothesis that nitric oxide (NO) production contributes to relaxation induced by 3',5'-cyclic adenylate monophosphate (cAMP)-elevating agents and that high salt diet impairs this mechanism of relaxation. Relaxation response to isoproterenol but not sodium nitroprusside, a NO donor, was reduced in the thoracic aorta from rats that were placed on a high salt diet (8% NaCl; 60+/-4%, P<0.001). 1H-[1,2,4]oxadiazolol [4,3,-alpha]quinoxalin-1-one (ODQ, 10 microM), a soluble guanylate cyclase inhibitor, but not N(omega)-nitro-L-arginine methyl ester (L-NAME, 100 microM), an inhibitor of NO synthase (NOS), attenuated the relaxation to isoproterenol (59+/-16%, P<0.01). High salt diet also impaired the relaxation responses to forskolin, an activator of adenylate cyclase, or 8-Bromo-cAMP (8-Br-cAMP). (N-[2-((p-bromocinnamyl)aminoethyl]-5-isoquinolinesulfonamide hydrochloride (H-89) (8 microM), an inhibitor of cAMP-dependent protein kinase, did not affect the relaxation produced by isoproterenol. These data suggest that high salt diet impairs relaxation response to isoproterenol by a dual mechanism involving diminished NO/NOS pathway linked to cGMP pathway and diminished cAMP pathway that is independent of protein kinase A.
Collapse
Affiliation(s)
- Olusoga Sofola
- College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004, USA
| | | | | | | | | |
Collapse
|
26
|
López-Hernández FJ, Carrón R, Montero MJ. Beneficial effects of trandolapril in uninephrectomized spontaneously hypertensive rats: role of cyclooxygenase pathway. Pharmacol Toxicol 2002; 91:90-6. [PMID: 12420798 DOI: 10.1034/j.1600-0773.2002.910208.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The antihypertensive efficacy of the angiotensin-converting enzyme inhibitor trandolapril was evaluated in uninephrectomized spontaneously hypertensive rats. After 5 weeks of treatment, blood pressure, cardiac and aortic mass, as well as the functional status of the aortic endothelium, and the role played by the cyclooxygenase pathway were investigated. In addition, the effect of a sub-antihypertensive dose of the calcium antagonist verapamil, in combination with trandolapril, was also investigated. As compared to placebo, trandolapril returned blood pressure and aortic lamina media cross sectional area to normotensive values, significantly reduced the heart-to-body weight, and improved the acetylcholine-induced relaxation of aortic rings. This latter effect is thought to be mediated by the elimination of a substance derived from the cyclooxygenase pathway. Verapamil, in single therapy, did not reduce blood pressure, or heart-to-body weight, increased aortic lamina media cross sectional area and impaired acetylcholine-induced relaxation. When combined with trandolapril in dual therapy, some of the beneficial effects of trandolapril remained, whereas others were counterbalanced by verapamil. In conclusion, trandolapril proved to be an effective therapeutic drug in this animal model of hypertension. Combination of trandolapril with a sub-antihypertensive dose of verapamil did not show any positive synergistic effect; on the contrary, it outweighed some of the beneficial effects of trandolapril.
Collapse
|
27
|
Hseu YC, Wang SY, Chen HY, Lu FJ, Gau RJ, Chang WC, Liu TZ, Yang HL. Humic acid induces the generation of nitric oxide in human umbilical vein endothelial cells: stimulation of nitric oxide synthase during cell injury. Free Radic Biol Med 2002; 32:619-29. [PMID: 11909696 DOI: 10.1016/s0891-5849(02)00752-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Humic acid (HA) has been implicated as an etiological factor in the peripheral vasculopathy of blackfoot disease (BFD). In this study, we examined the effects of HA upon the generation of nitric oxide (NO) during the process of lethal cell injury in cultured human umbilical vein endothelial cells (HUVECs). NO production was measured by the formation of nitrite (NO(2)(-)), the stable end-metabolite of NO. Cell death was assessed by measuring the release of intracellular lactate dehydrogenase (LDH). Treatment HUVECs with HA at a concentration of 50, 100, and 200 microg/ml concentration-dependently increased nitrite levels, reaching a peak at 12 h subsequent to HA treatment, with a maximal response of approximately 400 pmole nitrite (from 1 x 10(4) cells). HA-induced nitrite formation was blocked completely by N(G)-nitro-L-arginine methyl ester (L-NAME) and also by N(G)-methyl-L-arginine (L-NMA), both being specific inhibitors of NO synthase. The LDH released from endothelial cells was evoked at from 24 h after the addition of HA (50, 100, 200 microg/ml) in a concentration- and time-dependent manner. The HA-induced LDH release was also reduced by the presence of both L-NAME and L-NMA. The addition of Ca(2+) chelator (BAPTA) inhibited both nitrite formation and LDH release by HA. Moreover, the antioxidants (superoxide dismutase, vitamin C, vitamin E) and protein kinase inhibitor (H7) effectively suppressed HA-induced nitrite formation. These results suggest that HA treatment of endothelial cells stimulates NO production, which can elicit cell injury via the stimulation of Ca(2+)-dependent NO synthase activity by increasing cytosolic Ca(2+) levels. Because the destruction of endothelial cells has been implicated in triggering the onset of BFD, the induction of excessive levels of NO and consequent endothelial-cell injury may be important to the etiology of HA-induced vascular disorders associated with BFD for humans.
Collapse
Affiliation(s)
- You Cheng Hseu
- Department of Medical Technology, Fooyin Institute of Technology, Kaohsiung, Taiwan
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Doroudi R, Gan LM, Sjögren LS, Jern S. Intraluminal pressure modulates eicosanoid enzyme expression in vascular endothelium of intact human conduit vessels at physiological levels of shear stress. J Hypertens 2002; 20:63-70. [PMID: 11791027 DOI: 10.1097/00004872-200201000-00010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Biosynthesis of eicosanoid metabolites in blood vessels regulates vascular tone and platelet function. We investigated whether intraluminal pressure modulates gene and protein expression of key eicosanoid enzymes in intact human conduit vessels and/or release of their vasoactive metabolites. METHODS Paired segments of human umbilical veins were perfused under laminar flow for 1.5, 3 and 6 h at high versus low intraluminal pressure (40/20 mmHg) with identical shear stress (10 dyn/cm(2)). Endothelial cell mRNAs encoding cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), prostaglandin synthase (PGS), and thromboxane synthase (TXS) were measured by quantitative real-time RT-PCR. Secretion of PGI2 and TXA2 to the perfusion medium was measured by enzyme immunoassay of their metabolites 6-keto-prostaglandin F(1alpha) and TXB2. RESULTS Intraluminal pressures were 39.9 +/- 0.02 and 20.0 +/- 0.03 mmHg (P < 0.0001) in high and low pressure circuits, and shear stress levels were 10.6 +/- 0.60 and 9.7 +/- 0.36 dyn/cm(2) (NS, not significant). COX-1 mRNA was significantly up-regulated after 1.5 h of high pressure stimulation and continued up to 3 h, but fell thereafter significantly below baseline after 6 h. COX-2 mRNA was initially significantly down-regulated, followed by a significant up-regulation after 6 h. Gene expressions of PGS and TXS were significantly induced after 6 h of high pressure perfusion. High pressure depressed the production of PGI(2) (P < 0.05) but did not alter TXA(2) formation. CONCLUSIONS Intraluminal pressure has differential effects on gene and protein expression of key eicosanoid enzymes and biosynthesis of prostanoid metabolites in intact human conduit vessels. The new, computerized biomechanical perfusion system may be a useful tool to elucidate specific effects of various biomechanical forces on intact mammalian conduit vessels.
Collapse
Affiliation(s)
- Roya Doroudi
- Clinical Experimental Research Laboratory, Heart and Lung Institute, Sahlgrenska University Hospital/Ostra, Göteborg University, S-416 85 Göteborg, Sweden
| | | | | | | |
Collapse
|
29
|
|
30
|
Abstract
Loss of renal function beyond a renal vascular lesion presents a complex challenge to clinicians. This article summarizes current understanding of critical vascular lesions to the kidney and putative mechanisms by which loss of perfusion activates fibrogenic mechanisms in the kidney. The authors emphasize alterations in vasoactive pathways, including disturbed oxidative stress, activation of endothelin, and reduced nitric oxide, which modulate cytokines and inflammatory mediators within the renal parenchyma. Improved understanding of these mechanisms is essential in preventing irreversible interstitial fibrosis and restoring renal perfusion.
Collapse
Affiliation(s)
- L Lerman
- Divisions of Hypertension and Nephrology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | | |
Collapse
|
31
|
Kagota S, Tamashiro A, Yamaguchi Y, Sugiura R, Kuno T, Nakamura K, Kunitomo M. Downregulation of vascular soluble guanylate cyclase induced by high salt intake in spontaneously hypertensive rats. Br J Pharmacol 2001; 134:737-44. [PMID: 11606313 PMCID: PMC1572996 DOI: 10.1038/sj.bjp.0704300] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2001] [Revised: 07/11/2001] [Accepted: 07/25/2001] [Indexed: 02/05/2023] Open
Abstract
1. Cyclic guanosine monophosphate (cyclic GMP)-mediated mechanism plays an important role in vasodilatation and blood pressure regulation. We investigated the effects of high salt intake on the nitric oxide (NO) - cyclic GMP signal transduction pathway regulating relaxation in aortas of spontaneously hypertensive rats (SHR). 2. Four-week-old SHR and normotensive Wistar-Kyoto rats (WKY) received a normal salt diet (0.3% NaCl) or a high salt diet (8% NaCl) for 4 weeks. 3. In aortic rings from SHR, endothelium-dependent relaxations in response to acetylcholine (ACh), adenosine diphosphate (ADP) and calcium ionophore A23187 were significantly impaired by the high salt intake. The endothelium-independent relaxations in response to sodium nitroprusside (SNP) and nitroglycerin were also impaired, but that to 8-bromo-cyclic GMP remained unchanged. On the other hand, high salt diet had no significant effects on the relaxations of aortic rings from WKY. 4. In aortas from SHR, the release of NO stimulated by ACh was significantly enhanced, whereas the production of cyclic GMP induced by either ACh or SNP was decreased by the high salt intake. 5. Western blot analysis showed that the protein level of endothelial NO synthase (eNOS) was slightly increased, whereas that of soluble guanylate cyclase (sGC) was dramatically reduced by the high salt intake. 6. These results indicate that in SHR, excessive dietary salt can result in downregulation of sGC followed by decreased cyclic GMP production, which leads to impairment of vascular relaxation in responses to NO. It is notable that chronic high salt intake impairs the sGC/cyclic GMP pathway but not the eNOS/NO pathway.
Collapse
Affiliation(s)
- S Kagota
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, 11-68 Koshien Kyuban-cho, Nishinomiya 663-8179, Japan.
| | | | | | | | | | | | | |
Collapse
|
32
|
Abstract
Chronic azotemic renovascular disease is common in patients with atherosclerosis. Its prevalence appears to be increasing in the aging population. How often it is the primary cause of end-stage renal disease (ESRD) is not yet certain. Some studies suggest that 10%-40% of elderly hypertensive patients with newly documented ESRD and no demonstrable primary renal disease have significant renal artery stenosis (RAS). Atherosclerotic vascular occlusive disease of the renal arteries does progress, but current rates of progression and occlusion are lower than those reported a decade ago. Methods of identifying patients whose renal function is at true risk from vascular occlusive disease and determining who will benefit from intervention remain elusive. The presence of RAS in an azotemic patient can be assessed with noninvasive and risk-free radiologic techniques, including Duplex doppler velicometry and magnetic resonance angiography. Functional tests that predict the change in renal function after revascularization are not yet available. However, a renal length of greater than 7.5 cm in the absence of renal cysts and a short history of renal functional deterioration indicate a good prognosis. Patients with recent deterioration in renal function, those with bilateral renal artery stenosis or stenosis to a single functioning kidney, those with flash pulmonary edema, advanced chronic renal failure, or ESRD (who have much to gain), those with reversible azotemia during angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor antagonist (ARB) therapy, and those whose conditions cannot be managed medically should be considered for revascularization. Results from recent controlled clinical trials of the response to percutaneous transluminal renal artery angioplasty (PTRA) and stenting indicate that improvement in blood pressure control or renal function is not a predictable outcome of renal revascularization. In azotemic groups, 25%-30% of patients achieve important recovery of renal function. Thus, significant progress has been made recently in determining whether RAS is a frequent, treatable cause of renal failure. The decision to recommend revascularization remains a difficult balance between the risks and expense of the procedure and the undoubted benefits that accrue if renal function is successfully stabilized.
Collapse
Affiliation(s)
- S C Textor
- Divisions of Hypertension and Nephrology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA.
| | | |
Collapse
|
33
|
Zicha J, Dobesová Z, Kunes J. Relative deficiency of nitric oxide-dependent vasodilation in salt-hypertensive Dahl rats: the possible role of superoxide anions. J Hypertens 2001; 19:247-54. [PMID: 11212967 DOI: 10.1097/00004872-200102000-00011] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE The contribution of major vasoactive systems (renin-angiotensin system, sympathetic nervous system and nitric oxide) to blood pressure maintenance and the possible involvement of superoxide anions in the reduced efficiency of nitric oxide (NO)-dependent vasodilation to counterbalance sympathetic vasoconstriction were studied in salt-hypertensive Dahl rats. DESIGN AND METHODS We used Dahl salt-sensitive (SS/Jr) and salt-resistant (SR/Jr) female rats kept on a low-salt (0.3% NaCl) or high-salt diet (8% NaCl) for 6 weeks since weaning. Mean arterial pressure (MAP) was measured in conscious animals subjected to acute consecutive blockade of the renin-angiotensin system (RAS) [captopril, 10 mg/kg intravenously (i.v.)], the sympathetic nervous system (SNS) (pentolinium, 5 mg/kg i.v.) and NO synthase (Nomega-nitro-L-arginine methyl ester (L-NAME), 30 mg/kg i.v.). Before the consecutive blockade of vasoactive systems one-half of the animals in each experimental group was pre-treated with a stable membrane-permeable mimetic of superoxide dismutase (tempol, 25 mg/kg i.v.) which functions as a superoxide scavenger. RESULTS Compared to normotensive SR/Jr animals, salt-hypertensive SS/Jr rats were characterized by an enhanced blood pressure (BP) fall after ganglionic blockade (-104 +/- 8 versus -62 +/- 5 mm Hg, P < 0.001) and by higher residual blood pressure recorded after the blockade of both RAS and SNS (70 +/- 3 versus 43 +/- 3 mmHg, P < 0.01), but there was only a borderline elevation of their BP response to acute NO synthase inhibition (67 +/- 6 versus 49 +/- 4 mmHg, P < 0.05). The acute tempol pre-treatment elicited the most pronounced reduction of basal BP (-13 +/- 1 mmHg, P < 0.001) in the salt-hypertensive SS/Jr group in which the BP rise after L-NAME administration was augmented by about 50%. On the contrary, tempol pre-treatment did not affect norepinephrine- or angiotensin II-dependent vasoconstriction. CONCLUSIONS The NO system is not able to counterbalance effectively the hyperactivity of the sympathetic nervous system in salt-hypertensive Dahl rats. The predominance of sympathetic vasoconstriction over NO-dependent vasodilation could be explained partially by enhanced NO inactivation due to augmented superoxide anion formation in hypertensive animals.
Collapse
Affiliation(s)
- J Zicha
- Institute of Physiology, Academy of Sciences of the Czech Republic, and Center for Experimental Research of Cardiovascular Diseases, Prague.
| | | | | |
Collapse
|
34
|
Llinás MT, Rodríguez F, Moreno C, Salazar FJ. Role of cyclooxygenase-2-derived metabolites and nitric oxide in regulating renal function. Am J Physiol Regul Integr Comp Physiol 2000; 279:R1641-6. [PMID: 11049846 DOI: 10.1152/ajpregu.2000.279.5.r1641] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to examine the relative contribution of both cyclooxygenase (COX) isoforms in producing the prostaglandins (PG) involved in the regulation of renal function, when nitric oxide (NO) synthesis is reduced. In anesthetized dogs with reduction of NO synthesis, the renal effects of a nonisozyme-specific COX inhibitor (meclofenamate) were compared with those elicited by a selective COX-2 inhibitor (nimesulide) before and during an extracellular volume expansion (ECVE). Intrarenal N(G)- nitro-L-arginine methyl ester (L-NAME) infusion (1 microg x kg(-1) x min(-1); n = 6) did not elicit renal hemodynamic changes and reduced (P < 0.01) the renal excretory response to ECVE. Intravenous nimesulide (5 microg x kg(-1) x min(-1); n = 6) did not modify renal hemodynamic and reduced (P < 0. 05) sodium excretion before ECVE. Simultaneous L-NAME and nimesulide infusion (n = 7) elicited an increment (37%) in renal vascular resistance (RVR; P < 0.05) before ECVE and no hemodynamic changes during ECVE. The reduced excretory response elicited by L-NAME and nimesulide was similar to that found during L-NAME infusion. Finally, simultaneous L-NAME and meclofenamate infusion (10 microg x kg(-1) x min(-1); n = 7) induced an increase in RVR (91%, P < 0.05), a decrease in glomerular filtration rate (35%, P < 0.05), and a reduction of the renal excretory response to ECVE that was greater (P < 0.05) than that elicited by L-NAME alone. The results obtained support the notion that PG involved in regulating renal hemodynamic and excretory function when NO synthesis is reduced are mainly dependent on COX-1 activity.
Collapse
Affiliation(s)
- M T Llinás
- Department of Physiology, School of Medicine, University of Murcia, 30100 Murcia, Spain
| | | | | | | |
Collapse
|
35
|
Gan LM, Selin-Sjögren L, Doroudi R, Jern S. Temporal regulation of endothelial ET-1 and eNOS expression in intact human conduit vessels exposed to different intraluminal pressure levels at physiological shear stress. Cardiovasc Res 2000; 48:168-77. [PMID: 11033119 DOI: 10.1016/s0008-6363(00)00174-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE By using a computerized vascular perfusion model, we investigated temporal effects of sub-acute pressure elevation on vasomotor behavior and expression of endothelin-1 (ET-1) and endothelial nitric oxide synthase (eNOS) in intact human conduit vessels. METHODS Paired umbilical veins were perfused during 1.5, 3 and 6 h under high/low intraluminal pressure (40/20 mmHg) and at identical shear stress level of 10 dyn/cm(2). ET-1 and eNOS gene and protein expression was quantified with real-time reverse-transcribed polymerase chain reaction and quantitative immunohistochemistry, respectively. RESULTS Pressure induced differential temporal regulation patterns of ET-1 and eNOS gene expression. During the high pressure condition, eNOS mRNA was upregulated after 3 h and leveled off after 6 h of perfusion, while ET-1 mRNA was elevated after 6 h perfusion. Immunohistochemistry verified synchronal changes at the protein level. Significant vasodilation was observed after 3 h in the high-pressure system. CONCLUSION Thus, subacute pressure elevation exerts differential effects on the endothelial eNOS/ET-1 expression, which dynamically regulate the vasomotor tone.
Collapse
Affiliation(s)
- L M Gan
- Clinical Experimental Research Laboratory, Heart and Lung Institute, Sahlgrenska University Hospital/Ostra, Göteborg University, SE 416 85, Gothenburg, Sweden
| | | | | | | |
Collapse
|
36
|
Abstract
The authors investigated the vasorelaxant properties of the omega-3 fatty acid, docosahexaenoic (DHA, 22:6n-3), and the possible involvement of endothelium-derived nitric oxide, prostanoids, opening of K+ channels, and/or modulation of calcium-mediated events. Isolated aorta from male spontaneously hypertensive rats (SHR) (age 16-17 weeks) were used to measure isometric tension. DHA-induced (1-100 mumol/l) relaxation was examined following contraction to norepinephrine (NE) (10(-6) mol/l) or high-K+ (80 mmol/l) solution in the presence and absence of various inhibitors and calcium-containing solution. DHA acid induced a significant vasorelaxant effect in both NE and high-K(+)-induced contracted SHR aortic rings, although DHA relaxations were greater in high-K(+)-induced contracted rings. In the absence of extracellular calcium, DHA (5-30 mumol/l) inhibited the initial phasic and sustained components of NE-induced contraction under different conditions. Inhibition of nitric oxide synthesis by N omega-nitro-L-arginine methyl ester hydrochloride (100 mumol/l) had no effect on DHA relaxations; however, indomethacin or nifedipine caused significant inhibition at > or = 30 mumol/l DHA. The K+ channel blocker, glibenclamide, but not tetraethyl-ammonium, also had an inhibitory effect on DHA-induced relaxation. These results indicate that DHA's vasorelaxant actions in SHR aorta are independent of endothelium-derived nitric oxide; however, at DHA concentrations > or = 30 mumol/l, vasodilatory prostanoids that activate ATP-sensitive K+ channels (KATP) may be involved. At lower concentrations, DHA-induced relaxation appears to be attributed to modulation of intracellular Ca2+ release and L-type Ca2+ channels in vascular smooth muscle cells. The vasorelaxant properties of DHA may contribute, in part, to the blood pressure-lowering effect of dietary fish oil in this hypertensive model.
Collapse
Affiliation(s)
- M B Engler
- Department of Physiological Nursing, Laboratory of Cardiovascular Physiology, University of California, San Francisco, USA
| | | |
Collapse
|
37
|
Abstract
The endothelial cells release both relaxing [nitric oxide (NO), endothelium-derived hyperpolarizing factor (EDHF), prostacyclin] and contracting factors [endoperoxides, thromboxane A(2), superoxide anions, endothelin-1 (ET)]. The production of ET is inhibited by NO. The latter also strongly opposes the direct effects of the former on vascular smooth muscle. With aging and vascular disease, the production of enothelial NO declines, and thus ET can be released, act and contribute to the symptoms.
Collapse
Affiliation(s)
- P M Vanhoutte
- Institut de Recherches Internationales Servier, 6, Place des Pléïades, 92415 cedex, Courbevoie, France
| |
Collapse
|
38
|
Abstract
At one time considered merely a monolayer of cells lining the vascular conduit, the endothelium has emerged recently as an organ with functions as complex as any in the body. A highly active regulatory organ, the endothelium senses and assesses the hemodynamic, humoral, and inflammatory signals to which it is constantly exposed by the blood and responds by secreting factors that affect vessel tone and structure. These interactions are not merely of academic interest. It has been increasingly recognized that endothelial dysfunction plays a pivotal role in the development and progression of atherosclerosis and coronary artery disease.
Collapse
Affiliation(s)
- J P Cooke
- Division of Cardiovascular Medicine, Stanford University School of Medicine, CA 94305, USA
| |
Collapse
|
39
|
Abstract
In this review, we attempt to outline the age-dependent interactions of principal systems controlling the structure and function of the cardiovascular system in immature rats developing hypertension. We focus our attention on the cardiovascular effects of various pharmacological, nutritional, and behavioral interventions applied at different stages of ontogeny. Several distinct critical periods (developmental windows), in which particular stimuli affect the further development of the cardiovascular phenotype, are specified in the rat. It is evident that short-term transient treatment of genetically hypertensive rats with certain antihypertensive drugs in prepuberty and puberty (at the age of 4-10 wk) has long-term beneficial effects on further development of their cardiovascular apparatus. This juvenile critical period coincides with the period of high susceptibility to the hypertensive effects of increased salt intake. If the hypertensive process develops after this critical period (due to early antihypertensive treatment or late administration of certain hypertensive stimuli, e.g., high salt intake), blood pressure elevation, cardiovascular hypertrophy, connective tissue accumulation, and end-organ damage are considerably attenuated compared with rats developing hypertension during the juvenile critical period. As far as the role of various electrolytes in blood pressure modulation is concerned, prohypertensive effects of dietary Na+ and antihypertensive effects of dietary Ca2+ are enhanced in immature animals, whereas vascular protective and antihypertensive effects of dietary K+ are almost independent of age. At a given level of dietary electrolyte intake, the balance between dietary carbohydrate and fat intake can modify blood pressure even in rats with established hypertension, but dietary protein intake affects the blood pressure development in immature animals only. Dietary protein restriction during gestation, as well as altered mother-offspring interactions in the suckling period, might have important long-term hypertensive consequences. The critical periods (developmental windows) should be respected in the future pharmacological or gene therapy of human hypertension.
Collapse
Affiliation(s)
- J Zicha
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
| | | |
Collapse
|
40
|
Abstract
A change in endothelial function is a common phenomenon in patients with essential hypertension and in animals with hypertension, whether primary or induced by a salt-rich diet. In hypertensive subjects, there may be a change in the synthesis, or the effect, of nitric oxide. Nevertheless, hypertensive vasoconstriction is at present associated, above all, with the degradation of this mediator by free radicals, such as the superoxide anion, released in the dysfunctional vascular endothelium. These radicals are also formed when hypoxanthine is turned into xanthine, and when the latter becomes uric acid, both having been catalysed by the enzyme xanthine oxidase. In physiological conditions, the concentration of superoxide radicals remains low within the organism as a result of its reaction with the superoxide dismutase enzyme. However, in pathological situations, such as arterial hypertension, there may be an increase in the production of these radicals or a deficiency of the superoxide dismutase enzyme. In hypertensive patients, the release of vasoconstrictor peroxides derived from the activity of cyclo-oxygenase in the endothelium and the vascular smooth muscle is also important. The excess free radicals released by the dysfunctional endothelium also stimulate the synthesis of these contracting agents. Moreover, it should not be forgotten that endothelin-1, which is similarly synthesized and released in the vascular endothelium, is the most powerful known endogenous vasoconstrictor. This peptide would therefore play a prominent part in some forms of hypertension. Although no changes in endothelin plasma levels have been found in essential hypertension, there may be an increase in its local concentration. It should be borne in mind that endothelin could strengthen the effect of other vasoconstrictors. Moreover, it may also provoke the release of free radicals and of cyclo-oxygenase-derived vasoconstrictor factors. The latest theories therefore indicate that the increase in vasoconstriction, which characterizes arterial hypertension, is associated with a greater production of free radicals. At the present time, antioxidant agents and xanthine oxydase-inhibiting compounds are being used to treat hypertension and other pathologies linked to endothelial dysfunction. In addition, it is thought that the therapeutic benefit of some anti-hypertensive drugs, such as calcium antagonists and angiotensin-converting enzyme inhibitors, could be in part due to the inhibition of the production of free radicals that they provoke.
Collapse
Affiliation(s)
- A A De Artinano
- Departamento de Farmacologia, Facultad de Medicina, Universidad Complutense de Madrid, Ciudad Universitaria s/n., Madrid, 28040, Spain
| | | |
Collapse
|
41
|
Abstract
Since the discovery of the vasorelaxant properties of nitric oxide and the vasoconstrictor effect of endothelin-1, there have been many studies of the distribution and functional significance of these agents in various vascular beds. In the coronary and pulmonary circulation nitric oxide and endothelin-1 actions have been largely investigated in terms of an imbalance between the opposing effects of these vasoactive agents leading to pathophysiological conditions. This article review functional and immunocytochemical studies with emphasis on the ultrastructural localization of nitric oxide synthase and endothelin-1 in the coronary and pulmonary vascular beds. Localization of nitric oxide synthase (type III or I or II) has been shown in endothelial cells, smooth muscle, and perivascular nerves of the coronary and pulmonary vascular beds and in the neurons, nerve fibers, and the small granule-containing cells within cardiac ganglia. Endothelin-1 was mainly localized in subpopulations of coronary and pulmonary endothelial cells. These immunocytochemical studies provide information about the sources of nitric oxide and endothelin-1 that contribute to the vasomotor control of cardiac and pulmonary circulation under normal and pathophysiological conditions.
Collapse
Affiliation(s)
- A Rubino
- Autonomic Neuroscience Institute, Royal Free and University College Medical School, London, United Kingdom
| | | | | |
Collapse
|
42
|
López-Hernández FJ, Carrón R, Montero MJ, Flores O, López-Novoa JM, Arévalo MA. Antihypertensive effect of trandolapril and verapamil in rats with induced hypertension. J Cardiovasc Pharmacol 1999; 33:748-55. [PMID: 10226862 DOI: 10.1097/00005344-199905000-00011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The antihypertensive effect of long-term treatment (6 months) with placebo (as control), verapamil, trandolapril, and their combination (verapamil plus trandolapril) was investigated in Wistar rats rendered hypertensive by extensive renal mass ablation, as a model lacking genetic hypertensive determinants. Arterial pressure was monitored during treatment and at the end, aortic structure and functionality were investigated. Trandolapril and the combination prevented the increase in pressure observed in the control group after renal handicap, whereas verapamil was much less effective. Trandolapril and the combination were similarly effective, whereas verapamil was ineffective, or even deleterious, at reducing aortic lamina media hypertrophy, the wall-to-lumen ratio, lamina media cross-sectional area, potassium chloride-induced contraction, and at increasing acetylcholine relaxation. The response to noradrenaline decreased in the trandolapril group, increased in the verapamil group, and remained unmodified in the association group. In conclusion, treatment with trandolapril exerts beneficial antihypertensive actions in this model of induced hypertension, showing continuous control of blood pressure and prevention of structural and functional alteration of the aorta. Verapamil exerts weak control of arterial pressure and produces, if any, deleterious effects on the structure and function of the aorta. These negative effects of verapamil are overcome by coadministration of trandolapril.
Collapse
Affiliation(s)
- F J López-Hernández
- Department of Fisiología y Farmacología, Facultad de Medicina, Universidad de Salamanca, Spain
| | | | | | | | | | | |
Collapse
|
43
|
Kurbel S, Kurbel B, Kovacić D, Sulava D, Krajina Z, Dmitrović B, Sokcević M. Endothelin-secreting tumors and the idea of the pseudoectopic hormone secretion in tumors. Med Hypotheses 1999; 52:329-33. [PMID: 10465672 DOI: 10.1054/mehy.1997.0637] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Ectopic hormone secretion in tumor cells is here described as an amplification of hormone production already present in normal, nonendocrine tumor-originated tissue. This idea is tested on the available data regarding endothelin-1 (ET-1) secreting tumors. The endothelins are ubiquitous regulatory peptides produced by various tissues. The precursor cells of many tumor types secrete endothelins. ET-1 protein expression was detected in situ in all tested prostate cancers as well as in normal prostate tissue. The majority of hepatocellular carcinomas produce ET-1, while ET-1 is secreted by the normal hepatic stellate cells. Human breast cancer cells produce immunoreactive ET-1. Similar data exist for pancreatic tissue, the thyroid and large bowel. We can conclude that tumor cells might sustain endothelin secretions already present in the normal tumor-originated tissue. The model that is presented of the pseudoectopic hormone secretion consists of relations between a few parameters. The proportion of hormone-secreting tumors (Th) among all tumors (T) of that organ depends on the amount of the hormone-secreting cells (Ch) among all cells (C) susceptible to malignant transformation. The corrective factor (k) was introduced in the expression Th/T=Ch/C*k, to represent specific conditions altering the malignant transformation probability for a certain normal hormone-secreting cell. In prostate, breast and colon, the kvalue is predicted to be approximately 1, suggesting that ET-1-secreting normal cells are not more prone to the malignant transformation than their neighbours. In liver and pancreas, the incidence of ET-1-secreting tumors outnumbers the proportions of normal ET-1-secreting cells (k values >1). In these organs, normal ET-1-secreting cells seem more likely to turn malignant in comparison to their neighbours, perhaps due to their function, position and exposition to oncogenic factors, or even due to their ET-1 secretion. There are similar data for thyroid and adrenal glands. No ET-1 secretion was reported in kidney neoplasms. Normal renal ET-1 secreting cells might be less prone to turn malignant than other renal cells. Unlse the normal lung tissue, small cell lung cancers often secrete adrenocorticotrophic hormone (ACTH). The pancreatic islet cells do not secrete gastrin, but their tumors often do. Constant k would exceed 1 in both cases. We speculate that these tumors might originate from a small subset of cells with the described feature. Tumor cells sometimes lack features of the normal tissue, as in the cases of the steroid receptor-negative breast cancer. These tumors might originate from the hypothetical subset of receptor-free breast cells. Benign breast epithelial cells lacking oestrogen receptors have been described in cases of megalomastia. These cells might be constituents of normal breasts or, perhaps, present only in cases of increased breast cancer risk.
Collapse
Affiliation(s)
- S Kurbel
- Department of Oncology, Osijek Clinical Hospital, Croatia.
| | | | | | | | | | | | | |
Collapse
|
44
|
Montagnani M, Potenza MA, Rinaldi R, Mansi G, Nacci C, Serio M, Vulpis V, Pirrelli A, Mitolo-Chieppa D. Functional characterization of endothelin receptors in hypertensive resistance vessels. J Hypertens 1999; 17:45-52. [PMID: 10100093 DOI: 10.1097/00004872-199917010-00008] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
OBJECTIVE The physiological and pathophysiological functions of endothelin-1 in modulating the regional blood flow of normal and spontaneously hypertensive rats (SHR) were studied in the perfused mesenteric vascular bed, a useful model for investigating resistance vessels. DESIGN AND METHODS We used 12-week-old SHR and Wistar-Kyoto (WKY) rats. Endothelin A (ETA) receptor responsiveness was evaluated by endothelin-1 (0.2-2 mumol/l) concentration-response curves, and repeated in the presence of indomethacin and the ETA and endothelin B (ETB) receptor antagonists BQ-485 and BQ-788, respectively. ETB receptor responsiveness was tested by sarafotoxin S6c concentration-response curves, obtained in the noradrenaline-precontracted mesenteric vascular bed, and repeated after treatment with BQ-788 and after endothelial denudation. RESULTS In both groups, endothelin-1 induced concentration-dependent contraction; SHR exhibited a markedly increased maximal effect compared with WKY rats (P < 0.01). BQ-485 produced a shift to the right for endothelin-1 concentration-response curves in both groups, with a higher pA2 (negative common logarithm of the antagonist that produces an agonist dose ratio of 2) value in SHR than in WKY rats (P < 0.01). The increase in the maximal effect produced by endothelin-1 in SHR was prevented by indomethacin, which also induced a significant increase in the endothelin-1 concentration producing the half-maximal response (EC50) in SHR (P < 0.05). Sarafotoxin S6c produced an ETB-dependent endothelium-mediated relaxant effect in WKY rats, which was not observed in SHR. CONCLUSIONS The higher vasoconstriction induced by endothelin-1 in SHR may be related to a greater number of available ETA receptors, due to the presence of an ETA receptor subtype. This mechanism may be linked to the production of prostanoids that add to the direct endothelin-1-evoked vasoconstriction. These results, together with the lack of relaxation in response to sarafotoxin S6c in SHR, suggest that an imbalance in the endothelin-1 ability to induce both contraction and relaxation is present in SHR with sustained hypertension, manifesting as a greater contractile effect evoked in this strain.
Collapse
Affiliation(s)
- M Montagnani
- Dipartimento di Farmacologia e Fisiologia Umana, Facoltà di Medicina e Chirurgia, Università di Bari, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Abstract
BACKGROUND Antibodies to endothelial cells (aECs) and to cardiolipin (aCLs) are implicated in autoimmune diseases like systemic lupus erythematosus vasculitis. Beta2-Glycoprotein 1 (beta2GP1) is a cofactor for aCLs. The present study investigated the possible role of aECs, aCLs, and abeta2GP1 in borderline hypertension. METHODS AND RESULTS Seventy-three men with borderline hypertension (BHT) and 73 age-matched normotensive (NT) men (diastolic blood pressure, 85 to 94 and <80 mm Hg, respectively) were recruited from a population screening program. Antibody levels were determined by ELISA. Presence of carotid atherosclerosis was determined by B-mode ultrasonography, and 29 individuals had atherosclerotic plaques. BHT men had significantly higher aEC and abeta2GP1 levels of IgG class than NT control subjects (P=0.029 and P=0.0001, respectively). aEC levels of IgM class were higher in BHT (P=0.012), but not abeta2GP1 levels. There was no correlation between aCL levels and BHT. Individuals with atherosclerotic plaques had significantly higher aEC levels of both IgG (P=0.042) and IgM subclasses (P=0.018) than those without plaques, but no difference was found in aCL and abeta2GP1 levels. Endothelin and aECs of IgM class were significantly associated. CONCLUSIONS We demonstrate the first evidence of a significant elevation of aEC and abeta2GP1 levels in borderline hypertension. These findings provide a new link between hypertension and atherosclerosis and indicate that humoral immune reactions to the endothelium may play an important role in both conditions.
Collapse
Affiliation(s)
- J Frostegård
- From the Department of Medicine, Unit of Rheumatology, Karolinska Hospital and Center of Molecular Medicine; the Department of Thoracic and Cardiovascular Surgery, Karolinska Hospital the Department of Medicine, Stockholm, Sweden
| | | | | | | | | |
Collapse
|
46
|
López-Hernández FJ, Flores O, López-Novoa JM, Montero MJ, Carrón R. Antihypertensive action of trandolapril and verapamil in spontaneously hypertensive rats after unilateral nephrectomy. J Cardiovasc Pharmacol 1998; 32:284-90. [PMID: 9700991 DOI: 10.1097/00005344-199808000-00016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
It is well documented that the kidney plays a fundamental role in long-term arterial pressure regulation, and, as an endocrine organ, in the regulation of cardiovascular structure and functionality. In this study, the antihypertensive effect of long-term treatment (6 months) with placebo, verapamil, trandolapril, and a combination of the latter (verapamil plus trandolapril) was investigated in spontaneously hypertensive rats after half-renal-mass ablation. Arterial pressure was monitored during treatment and at the end, aortic structure and functionality were investigated. Trandolapril and the combination returned pressure to normal, whereas verapamil was less effective. All three treatment groups were similarly effective at reducing aortic medial hypertrophy, the wall-to-lumen ratio, and contraction evoked by potassium chloride and noradrenaline. Verapamil and veratran were more effective than trandolapril at reducing lamina media cross-sectional area. Trandolapril and the combination were more effective than verapamil at improving endothelial dysfunction.
Collapse
|
47
|
Abstract
Recent studies indicate that arsenic may generate reactive oxygen species to exert its toxicity. Because reactive oxygen species are known to induce poly(ADP-ribosylation), which is implicated in DNA repair, signal transduction, and apoptosis, we have investigated the effect of arsenite on poly(ADP-ribosylation). The results showed that arsenite treatment induced poly(ADP-ribosylation), NAD depletion, DNA strand breaks, and micronuclei in CHO-K1 cells. Increase of nitrite level, a stable product of nitric oxide, was also detected in medium of arsenite-treated cultures. S-methyl-L-thiocitrulline and N omega-nitro-L-arginine methyl ester, inhibitors of nitric oxide synthase, could suppress the arsenite-induced NAD depletion, DNA strand breaks, and micronuclei, whereas 3-aminobenzamide, an inhibitor of poly (ADP-ribose) polymerase, could enhance micronucleus production and NAD depletion in arsenite-treated cells. These results suggest that arsenite treatment may generate nitric oxide to damage DNA and which then stimulate poly(ADP-ribosylation). Because arsenite also induced DNA strand breaks and NAD depletion in bovine aortic endothelial cells, and these could also be suppressed by S-methyl-L-thiocitrulline, the induction of nitric oxide may be important to the etiology of arsenic-induced vascular disorders in humans.
Collapse
Affiliation(s)
- S Lynn
- Institute of Zoology, Academia Sinica, Taipei, Taiwan, ROC
| | | | | | | |
Collapse
|
48
|
Affiliation(s)
- P A van Zwieten
- Department of Pharmacotherapy, University of Amsterdam, The Netherlands
| |
Collapse
|
49
|
Sagach VF, Bazilyuk OV, Oleshko NN, Maiskii VA, Costa A, Martignoni E, Qualls C, Appenzeller O. Mesostriatal lesions and endothelial function: Effects of forced movements and hypoxia on levels of circulating endothelins. NEUROPHYSIOLOGY+ 1998; 30:13-8. [DOI: 10.1007/bf02463107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
50
|
Fontana F, Bernardi P, Spampinato S, Boschi S, De Iasio R, Grossi G. Pressor effects of endogenous opioid system during acute episodes of blood pressure increases in hypertensive patients. Hypertension 1997; 29:105-10. [PMID: 9039088 DOI: 10.1161/01.hyp.29.1.105] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
To investigate the involvement of endogenous opioids in acute increases in blood pressure and their functional relationship with atrial natriuretic factor and endothelin-1, we assessed plasma levels of beta-endorphin, met-enkephalin, dynorphin B, catecholamines, atrial natriuretic factor, and endothelin-1 before and after administration of the opioid antagonist naloxone hydrochloride (8 mg i.v.) in 28 hypertensive patients with a stress-induced acute increase in blood pressure. Ten patients with established mild or moderate essential hypertension and 10 normotensive subjects served as control groups. Opioids, atrial natriuretic factor, and endothelin-I were radioimmunoassayed after chromatographic preextraction; catecholamines were determined by high-performance liquid chromatography with electrochemical detection. Patients with an acute increase in blood pressure (systolic, 203.2 +/- 2.2 mm Hg; diastolic, 108.4 +/- 1.3) had plasma opioid, catecholamine, and atrial natriuretic factor levels significantly (P < .01) higher than hypertensive control patients (systolic pressure, 176.4 +/- 1.0 mm Hg; diastolic, 100.0 +/- 1.4), who had a hormonal pattern similar to that of normotensive subjects (systolic pressure, 123.2 +/- 1.5 mm Hg; diastolic, 75.0 +/- 2.0). Endothelin-1 did not differ in any group. In patients with an acute increase in blood pressure, naloxone significantly (P < .01) reduced blood pressure, heart rate, opioids, catecholamines, and atrial natriuretic factor 10 minutes after administration. Naloxone effects on blood pressure, heart rate, opioids, and catecholamines wore off within 20 minutes. In control groups, naloxone failed to modify any of the considered parameters. Our findings suggest that pressor effects of opioid peptides mediated by the autonomic nervous system during stress-induced acute episodes of blood pressure increase in hypertensive patients.
Collapse
Affiliation(s)
- F Fontana
- Istituto di Patologia Speciale Medica e Metodologia Clinica, Ospedale S Orsola, Bologna, Italy
| | | | | | | | | | | |
Collapse
|