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Abstract
The microcirculation maintains tissue homeostasis through local regulation of blood flow and oxygen delivery. Perturbations in microvascular function are characteristic of several diseases and may be early indicators of pathological changes in the cardiovascular system and in parenchymal tissue function. These changes are often mediated by various reactive oxygen species and linked to disruptions in pathways such as vasodilation or angiogenesis. This overview compiles recent advances relating to redox regulation of the microcirculation by adopting both cellular and functional perspectives. Findings from a variety of vascular beds and models are integrated to describe common effects of different reactive species on microvascular function. Gaps in understanding and areas for further research are outlined. © 2020 American Physiological Society. Compr Physiol 10:229-260, 2020.
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Affiliation(s)
- Andrew O Kadlec
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Medical Scientist Training Program, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - David D Gutterman
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Department of Medicine-Division of Cardiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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Kadowaki D, Anraku M, Sakaya M, Hirata S, Maruyama T, Otagiri M. Olmesartan protects endothelial cells against oxidative stress-mediated cellular injury. Clin Exp Nephrol 2015; 19:1007-14. [PMID: 25904217 DOI: 10.1007/s10157-015-1111-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 03/25/2015] [Indexed: 01/13/2023]
Abstract
BACKGROUND The primary cause of death of hemodialysis (HD) patients is cardiovascular disease, and increased oxidative stress has been proposed to be involved in the disease pathogenesis. In this study, we examined the effect of olmesartan on oxidative stress induced by angiotensin II, lipopolysaccharide, indoxyl sulfate, advanced oxidation protein products (AOPP) or hydrogen peroxide (H2O2), which are known to be present at higher concentrations in the blood of HD patients, using human umbilical vein endothelial cells (HUVECs). METHODS Oxidative stress was evaluated by measuring the mean fluorescence intensity of CM-H2DCFCA, an ROS-sensitive fluorescent dye, in HUVECs. HUVECs were incubated with each of the above compounds in the presence or absence of olmesartan. Moreover, these oxidant-stimulated cells were also treated with the reactive oxygen species (ROS) inhibitor N-acetyl-cysteine (NAC), NADPH oxidase inhibitor diphenylene iodonium (DPI) or PKC inhibitor calphostin C. In addition, we investigated the effects of olmesartan on cytotoxicity and vascular endothelial growth factor (VEGF) secretion, which is involved in vascular inflammation in HUVECs induced by AOPP or H2O2. RESULTS The treatment of these oxidant-stimulated cells with olmesartan resulted in a significant reduction in intracellular ROS production to an extent that was nearly equivalent to that of NAC, DPI or calphostin C. Furthermore, olmesartan reduced the cytotoxicity and VEGF secretion induced by AOPP or H2O2. CONCLUSIONS These results demonstrated that the antioxidant activity of olmesartan might contribute to both its vasculoprotective and anti-hypertensive effects.
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Affiliation(s)
- Daisuke Kadowaki
- Department of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan
- Center for Clinical Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, Japan
- Department of Clinical Pharmacology, Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, Japan
| | - Makoto Anraku
- Faculty of Pharmaceutical Sciences, Sojo University, 4-22-1 Ikeda, Nishi-ku, Kumamoto, 860-0082, Japan
| | - Moe Sakaya
- Department of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan
| | - Sumio Hirata
- Center for Clinical Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, Japan
- Department of Clinical Pharmacology, Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, Japan
| | - Toru Maruyama
- Department of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, 862-0973, Japan.
- Center for Clinical Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Chuo-ku, Kumamoto, Japan.
| | - Masaki Otagiri
- Faculty of Pharmaceutical Sciences, Sojo University, 4-22-1 Ikeda, Nishi-ku, Kumamoto, 860-0082, Japan.
- DDS Research Institute, Sojo University, 4-22-1 Ikeda, Kumamoto, 860-0082, Japan.
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Nemeth Z, Cziraki A, Szabados S, Horvath I, Koller A. Pericardial fluid of cardiac patients elicits arterial constriction: role of endothelin-1. Can J Physiol Pharmacol 2015; 93:779-85. [PMID: 26322806 DOI: 10.1139/cjpp-2015-0030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recently, several vasoactive molecules have been found in pericardial fluid (PF). Thus, we hypothesized that in coronary artery disease due to ischemia or ischemia-reperfusion, the level of vasoconstrictors, mainly endothelin-1 (ET-1), increases in PF, which can increase the vasomotor tone of arteries. Experiments were performed using an isometric myograph. Vasomotor effects of PF from patients undergoing coronary artery bypass graft (PFCABG, n = 14) or valve replacement (PFVR, n = 7) surgery were examined in isolated rat carotid arteries (N = 14; n = 26). Vasomotor responses to KCl (40 or 60 mmol/L) were also tested. The selective endothelin A receptor antagonist BQ123 (10(-6) mol/L) was used to elucidate the role of ET-1. Both the first and the second additions of KCl elicited increases in the isometric force of the isolated arteries (KCl1, 6.1 ± 0.2 mN; KCl2, 6.5 ± 0.9 mN). PFCABG and PFVR elicited substantial increases in the isometric force of arteries (PFCABG, 3.1 ± 0.7 mN; PFVR, 3.0 ± 0.9 mN; p > 0.05). The presence of the selective endothelin A receptor blocker significantly reduced arterial contractions to PFCABG (before BQ123, 2.6 ± 0.5 mN vs. after BQ123, 0.8 ± 0.1 mN; p < 0.05). This study is the first to demonstrate that PFs of patients elicit substantial arterial constrictions, which is mediated primarily by ET-1. Interfering with the vasoconstrictor action of PF could be a potential therapeutic target to improve coronary blood flow in cardiac patients.
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Affiliation(s)
- Zoltan Nemeth
- a University of Pecs, Medical School, Department of Pathophysiology and Gerontology and Szentagothai Research Centre, Pecs, Hungary
| | - Attila Cziraki
- b University of Pecs, Medical School, Heart Institute, Pecs, Hungary
| | - Sandor Szabados
- b University of Pecs, Medical School, Heart Institute, Pecs, Hungary
| | - Ivan Horvath
- b University of Pecs, Medical School, Heart Institute, Pecs, Hungary
| | - Akos Koller
- a University of Pecs, Medical School, Department of Pathophysiology and Gerontology and Szentagothai Research Centre, Pecs, Hungary.,c University of Physical Education, Institute of Natural Sciences, Budapest, Hungary.,d Department of Physiology, New York Medical College, Valhalla, NY 10595, USA
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Czikora I, Feher A, Lucas R, Fulton DJR, Bagi Z. Caveolin-1 prevents sustained angiotensin II-induced resistance artery constriction and obesity-induced high blood pressure. Am J Physiol Heart Circ Physiol 2014; 308:H376-85. [PMID: 25527780 DOI: 10.1152/ajpheart.00649.2014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The type 1 angiotensin II (ANG II) receptor (AT1R) undergoes internalization following stimulation by ANG II. Internalization reduces cell surface AT1Rs, and it is required for AT1R resensitization. In this process AT1R may interact with caveolin-1 (Cav1), the main scaffolding protein of caveolae. We hypothesized that the interaction between Cav1 and AT1R delays AT1R resensitization and thereby prevents sustained ANG II-induced resistance artery (RA) constriction under normal conditions and in experimental obesity. In rat and mouse skeletal muscle RA (diameter: ∼90-120 μm) ANG II-induced constrictions were reduced upon repeated (30-min apart) administrations. Upon disruption of caveolae with methyl-β-cyclodextrin or in RA of Cav1 knockout mice, repeated ANG II applications resulted in essentially maintained constrictions. In vascular smooth muscle cells, AT1R interacted with Cav1, and the degree of cell surface interactions was reduced by long-term (15-min), but not short-term (2-min), exposure to ANG II. When Cav1 was silenced, the amount of membrane-associated AT1R was significantly reduced by a short-term ANG II exposure. Moreover, Cav1 knockout mice fed a high-fat diet exhibited augmented and sustained RA constriction to ANG II and had elevated systemic blood pressure, when compared with normal or high-fat fed wild-type mice. Thus, Cav1, through a direct interaction, delays internalization and subsequent resensitization of AT1R. We suggest that this mechanism prevents sustained ANG II-induced RA constriction and elevated systemic blood pressure in diet-induced obesity.
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Affiliation(s)
- Istvan Czikora
- Vascular Biology Center, Medical College of Georgia, Georgia Regents University, Augusta, Georgia
| | - Attila Feher
- Vascular Biology Center, Medical College of Georgia, Georgia Regents University, Augusta, Georgia
| | - Rudolf Lucas
- Vascular Biology Center, Medical College of Georgia, Georgia Regents University, Augusta, Georgia
| | - David J R Fulton
- Vascular Biology Center, Medical College of Georgia, Georgia Regents University, Augusta, Georgia
| | - Zsolt Bagi
- Vascular Biology Center, Medical College of Georgia, Georgia Regents University, Augusta, Georgia
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Durand MJ, Dharmashankar K, Bian JT, Das E, Vidovich M, Gutterman DD, Phillips SA. Acute exertion elicits a H2O2-dependent vasodilator mechanism in the microvasculature of exercise-trained but not sedentary adults. Hypertension 2014; 65:140-5. [PMID: 25368025 DOI: 10.1161/hypertensionaha.114.04540] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Brachial artery flow-mediated vasodilation in exercise-trained (ET) individuals is maintained after a single bout of heavy resistance exercise compared with sedentary individuals. The purpose of this study was to determine whether vasodilation is also maintained in the microcirculation of ET individuals. A total of 51 sedentary and ET individuals underwent gluteal subcutaneous fat biopsy before and after performing a single bout of leg press exercise. Adipose arterioles were cannulated in an organ bath, and vasodilation to acetylcholine was assessed±the endothelial nitric oxide inhibitorl-NG-nitroarginine methyl ester, the cyclooxygenase inhibitor indomethacin, or the hydrogen peroxide scavenger polyethylene glycol catalase. Separate vessels (isolated from the same groups) were exposed to an intraluminal pressure of 150 mm Hg for 30 minutes to mimic the pressor response, which occurs with isometric exercise. Vasodilation to acetylcholine was reduced in microvessels from sedentary subjects after either a single weight lifting session or exposure to increased intraluminal pressure, whereas microvessels from ET individuals maintained acetylcholine-mediated vasodilation. Before weight lifting, vasodilation of microvessels from ET individuals was reduced in the presence of l-NG-nitroarginine methyl ester and indomethacin. After weight lifting or exposure to increased intraluminal pressure, polyethylene glycol catalase significantly reduced vasodilation, whereas l-NG-nitroarginine methyl ester and indomethacin had no effect. These results indicate that (1) endothelium-dependent vasodilation in the microvasculature is maintained after heavy resistance exercise in ET individuals but not in sedentary subjects and that (2) high pressure alone or during weight lifting may induce a mechanistic switch in the microvasculature to favor hydrogen peroxide as the vasoactive mediator of dilation.
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Affiliation(s)
- Matthew J Durand
- From the Department of Medicine, Cardiovascular Center, Medical College of Wisconsin, Milwaukee (M.J.D., K.D., E.D., D.D.G.); and Department of Physical Therapy (J.-T.B., S.A.P.) and Department of Medicine, Cardiology (M.V., S.A.P.), University of Illinois at Chicago
| | - Kodlipet Dharmashankar
- From the Department of Medicine, Cardiovascular Center, Medical College of Wisconsin, Milwaukee (M.J.D., K.D., E.D., D.D.G.); and Department of Physical Therapy (J.-T.B., S.A.P.) and Department of Medicine, Cardiology (M.V., S.A.P.), University of Illinois at Chicago
| | - Jing-Tan Bian
- From the Department of Medicine, Cardiovascular Center, Medical College of Wisconsin, Milwaukee (M.J.D., K.D., E.D., D.D.G.); and Department of Physical Therapy (J.-T.B., S.A.P.) and Department of Medicine, Cardiology (M.V., S.A.P.), University of Illinois at Chicago
| | - Emon Das
- From the Department of Medicine, Cardiovascular Center, Medical College of Wisconsin, Milwaukee (M.J.D., K.D., E.D., D.D.G.); and Department of Physical Therapy (J.-T.B., S.A.P.) and Department of Medicine, Cardiology (M.V., S.A.P.), University of Illinois at Chicago
| | - Mladen Vidovich
- From the Department of Medicine, Cardiovascular Center, Medical College of Wisconsin, Milwaukee (M.J.D., K.D., E.D., D.D.G.); and Department of Physical Therapy (J.-T.B., S.A.P.) and Department of Medicine, Cardiology (M.V., S.A.P.), University of Illinois at Chicago
| | - David D Gutterman
- From the Department of Medicine, Cardiovascular Center, Medical College of Wisconsin, Milwaukee (M.J.D., K.D., E.D., D.D.G.); and Department of Physical Therapy (J.-T.B., S.A.P.) and Department of Medicine, Cardiology (M.V., S.A.P.), University of Illinois at Chicago
| | - Shane A Phillips
- From the Department of Medicine, Cardiovascular Center, Medical College of Wisconsin, Milwaukee (M.J.D., K.D., E.D., D.D.G.); and Department of Physical Therapy (J.-T.B., S.A.P.) and Department of Medicine, Cardiology (M.V., S.A.P.), University of Illinois at Chicago.
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Durand MJ, Phillips SA, Widlansky ME, Otterson MF, Gutterman DD. The vascular renin-angiotensin system contributes to blunted vasodilation induced by transient high pressure in human adipose microvessels. Am J Physiol Heart Circ Physiol 2014; 307:H25-32. [PMID: 24778165 DOI: 10.1152/ajpheart.00055.2014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Increased intraluminal pressure can reduce endothelial function in resistance arterioles; however, the mechanism of this impairment is unknown. The purpose of this study was to determine the effect of local renin-angiotensin system inhibition on the pressure-induced blunting of endothelium-dependent vasodilation in human adipose arterioles. Arterioles (100-200 μm) were dissected from fresh adipose surgical specimens, cannulated onto glass micropipettes, pressurized to an intraluminal pressure of 60 mmHg, and constricted with endothelin-1. Vasodilation to ACh was assessed at 60 mmHg and again after a 30-min exposure to an intraluminal pressure of 150 mmHg. The vasodilator response to ACh was significantly reduced in vessels exposed to 150 mmHg. Exposure of the vessels to the superoxide scavenger polyethylene glycol-SOD (100 U/ml), the ANG II type 1 receptor antagonist losartan (10(-6) mol/l), or the angiotensin-converting enzyme inhibitor captopril (10(-5) mol/l) prevented the pressure-induced reduction in ACh-dependent vasodilation observed in untreated vessels. High intraluminal pressure had no effect on papaverine-induced vasodilation or ANG II sensitivity. Increased intraluminal pressure increased dihydroethidium fluorescence in cannulated vessels, which could be prevented by polyethylene glycol-SOD or losartan treatment and endothelial denudation. These data indicate that high intraluminal pressure can increase vascular superoxide and reduce nitric oxide-mediated vasodilation via activation of the vascular renin-angiotensin system. This study provides evidence showing that the local renin-angiotensin system in the human microvasculature may be pressure sensitive and contribute to endothelial dysfunction after acute bouts of hypertension.
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Vamos Z, Ivic I, Cseplo P, Toth G, Tamas A, Reglodi D, Koller A. Pituitary adenylate cyclase-activating polypeptide (PACAP) induces relaxations of peripheral and cerebral arteries, which are differentially impaired by aging. J Mol Neurosci 2014; 54:535-42. [PMID: 24939249 DOI: 10.1007/s12031-014-0349-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 06/04/2014] [Indexed: 01/15/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a well-known neuropeptide, which also has vasomotor effects. However, little is known regarding its age-related and organ-specific vasomotor effects. We hypothesized that the vasomotor effects of PACAP depend on the tissue origin of the vessels and aging substantially modulates its actions. Thus, carotid (CA) and basilar arteries (BA) were isolated from young (2 months old), middle age (12 months old), and old (30 months old) rats. Their vasomotor responses were measured with an isometric myograph (DMT610M) in response to cumulative concentrations of PACAP1-38 (10(-9)-10(-6) M). PACAP1-38 induced (1) significantly greater concentration-dependent relaxations in CA compared to that of BA of young, middle age, and old rats; (2) relaxations of CA significantly decreased, whereas they did not change substantially in BA, as a function of age; (3) sodium nitroprusside (SNP)-induced relaxation did not change after PACAP1-38 administration in any conditions; and (4) inhibition of PAC1 receptors by selective PAC1 receptor blocker (PACAP6-38) completely diminished the responses to PACAP in all age groups of BA and CA. In conclusion, these findings suggest that PACAP1-38 has greater vasomotor effect in CA than that in BA, whereas aging has less effect on PACAP-induced relaxation of cerebral arteries and BA than that in peripheral arteries and CA suggesting that the relaxation to PACAP is maintained in cerebral arteries even in old age.
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Affiliation(s)
- Zoltan Vamos
- Department of Pathophysiology and Gerontology, Szentagothai Research Centre, University of Pecs, Medical School, Szigeti út 12, Pecs, 7624, Hungary
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Abstract
Exercise is a powerful therapy for preventing the onset of and slowing the progression of cardiovascular disease. Increased shear stress during exercise improves vascular homeostasis by both decreasing reactive oxygen species and increasing nitric oxide bioavailability in the endothelium. While these observations are well accepted as they apply to individuals at risk for cardiovascular disease, less is known about how exercise, especially intense exercise, affects vascular function in healthy individuals. This review highlights examples of how vascular function can paradoxically be impaired in otherwise healthy individuals by extreme levels of exercise, with a focus on the causative role that reactive oxygen species play in this impairment.
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Affiliation(s)
- Matthew J Durand
- Department of Medicine, Cardiology Division, and Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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Szijártó IA, Molnár GA, Mikolás E, Fisi V, Laczy B, Gollasch M, Koller A, Wittmann I. Increase in insulin-induced relaxation of consecutive arterial segments toward the periphery: Role of vascular oxidative state. Free Radic Res 2014; 48:749-57. [PMID: 24628420 DOI: 10.3109/10715762.2014.904507] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
RATIONALE The oxidative state has been implicated in the signaling of various vasomotor functions, yet its role regarding the vasomotor action of insulin is less known. OBJECTIVE To investigate the insulin-evoked relaxations of consecutive arterial segments of different oxidative state and the role of extracellular signal-regulated kinase (ERK) pathway. METHODS AND RESULTS The oxidative state, as assessed by the level of ortho-tyrosine, was higher in the thoracic aorta of rats than in the abdominal aorta, and was the lowest in the femoral artery. The vasomotor function of vessels of same origin was studied using a small-vessel myograph. Insulin-induced relaxations increased toward the periphery (i.e., thoracic < abdominal < femoral). Aortic banding and hydrogen peroxide/aminotriazole increased the oxidative state of the thoracic aorta that was accompanied by ERK activation and decreased relaxation to insulin, and vice versa, acutely lowered oxidative state by superoxide dismutase/catalase improved relaxation. In contrast, insulin-induced relaxation of the femoral artery could be enhanced with a higher oxidative state, and reduced with a lower state. CONCLUSIONS Oxidative state of vessels modulates the magnitude of vasomotor responses to insulin, which appears to be mediated via the ERK signaling pathway.
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Affiliation(s)
- I A Szijártó
- 2nd Department of Medicine and Nephrological Center, University of Pécs , Pécs , Hungary
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Vamos Z, Cseplo P, Ivic I, Matics R, Hamar J, Koller A. Age Determines the Magnitudes of Angiotensin II-Induced Contractions, mRNA, and Protein Expression of Angiotensin Type 1 Receptors in Rat Carotid Arteries. J Gerontol A Biol Sci Med Sci 2013; 69:519-26. [DOI: 10.1093/gerona/glt128] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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Spradley FT, Kang KT, Pollock JS. Short-term hypercaloric diet induces blunted aortic vasoconstriction and enhanced vasorelaxation via increased nitric oxide synthase 3 activity and expression in Dahl salt-sensitive rats. Acta Physiol (Oxf) 2013; 207:358-68. [PMID: 23176108 DOI: 10.1111/apha.12025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Revised: 09/02/2012] [Accepted: 09/27/2012] [Indexed: 02/03/2023]
Abstract
AIM To elucidate the role of the O(2)(-), H(2)O(2) or NO pathways in aortic angiotensin (Ang)II-induced vasoconstriction in Dahl salt-sensitive (SS) rats compared with control SS-13(BN) rats on a normal or hypercaloric diet. METHODS Aortic function was assessed using wire myography in 16-week-old rats maintained on a normal diet or a 4-week hypercaloric diet. Nitric oxide synthase (NOS) activity and expression was determined by the conversion of radio-labelled arginine to citrulline and Western blot analysis respectively. RESULTS On normal diet, AngII-induced vasoconstriction was greater in SS than SS-13(BN) rats. Polyethylene glycol superoxide dismutase (PEG-SOD) reduced the aortic AngII response similarly in both strains on normal diet. Catalase blunted, whereas N(ω)-Nitro-L-arginine methyl ester (L-NAME) did not affect the AngII response in SS rats. In SS-13(BN) rats, catalase had no effect and L-NAME enhanced AngII response. On hypercaloric diet, aortic AngII responsiveness was reduced in SS but unaltered in SS-13(BN) rats compared with their normal diet counterparts. PEG-SOD reduced the AngII response in both rats on hypercaloric diet. Catalase treatment did not alter aortic AngII response, while L-NAME increased the response in SS rats on hypercaloric diet. In SS-13(BN) rats on hypercaloric diet, catalase reduced and L-NAME did not alter the AngII response. Furthermore, aortic endothelial-dependent vasorelaxation was increased in SS rats on hypercaloric diet compared with normal diet and aortic NOS3 activity and expression was increased. CONCLUSION A short-term hypercaloric diet induces a blunted vasoconstrictive and enhanced vasodilatory phenotype in SS rats, but not in SS-13(BN) rats, via reduced H(2)O(2) and increased NOS3 function.
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Affiliation(s)
| | - K.-T. Kang
- Vascular Biology Center; Medical College of Georgia; Georgia Health Sciences University; Augusta; GA; USA
| | - J. S. Pollock
- Section of Experimental Medicine; Department of Medicine; Medical College of Georgia; Georgia Health Sciences University; Augusta; GA; USA
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Hamar J, Solymár M, Tanai E, Cseplo P, Springo Z, Berta G, Debreceni B, Koller A. Bioassay-comparison of the antioxidant efficacy of hydrogen sulfide and superoxide dismutase in isolated arteries and veins. ACTA ACUST UNITED AC 2013; 99:411-9. [PMID: 23238543 DOI: 10.1556/aphysiol.99.2012.4.5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Recent studies suggest that hydrogen sulfide (H2S) exhibits potent antioxidant capacity and improves vascular and tissue functions. Thus we aimed to compare the antioxidant efficacy of H2S to that of superoxide dismutase (SOD).Isometric force of isolated rat carotid arteries and gracilis veins was measured with a myograph. The vasomotor effect of the superoxide-generator pyrogallol (10-5M) was obtained in control conditions, and then in the presence of SOD (120 U/ml) or H2S (10-5M or 10-4M), respectively. Spectrophotometric measurements were performed to detect the effect of SOD and H2S on the auto-oxidation of pyrogallol.Pyrogallol increased the isometric force of carotid arteries (9.7 ± 0.8 mN), which was abolished by SOD (5.3 ± 0.8 mN), was not affected by 10-5M H2S (9.1 ± 0.5 mN), whereas 10-4M H2S slightly, but significantly reduced it (8.1 ± 0.7 mN). Pyrogallol significantly increased the isometric force of gracilis veins (1.3 ± 0.2 mN), which was abolished by SOD (0.9 ± 0.2 mN), whereas 10-5M (1.3 ± 0.2 mN), or 10-4M H2S (1.2 ± 0.2 mN) did not affect it. Pyrogallol-induced superoxide production was measured by a spectrophotometer (A420 = 0.19 ± 0.0). SOD reduced absorbance (A420 = 0.02 ± 0.0), whereas 10-5M H2S did not (A420 = 0.18 ± 0.0) and 10-4M H2S slightly reduced it (A420 = 0.15 ± 0.0).These data suggest that H2S is a less effective vascular antioxidant than SOD. We propose that the previously described beneficial effects of H2S are unlikely to be related to its direct effect on superoxide.
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Affiliation(s)
- J Hamar
- Department of Pathophysiology and Gerontology, University of Pécs, Pécs Hungary
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Development of Angiotensin II-induced Abdominal Aortic Aneurysms Is Independent of Catalase in Mice. J Cardiovasc Pharmacol 2011; 58:633-8. [DOI: 10.1097/fjc.0b013e3182317196] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Bagi Z, Feher A, Cassuto J, Akula K, Labinskyy N, Kaley G, Koller A. Increased availability of angiotensin AT 1 receptors leads to sustained arterial constriction to angiotensin II in diabetes - role for Rho-kinase activation. Br J Pharmacol 2011; 163:1059-68. [PMID: 21385178 DOI: 10.1111/j.1476-5381.2011.01307.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Antagonists of angiotensin AT(1) receptors elicit beneficial vascular effects in diabetes mellitus. We hypothesized that diabetes induces sustained availability of AT(1) receptors, causing enhanced arterial constriction to angiotensin II. EXPERIMENTAL APPROACH To assess functional availability of AT(1) receptors, constrictions to successive applications of angiotensin II were measured in isolated skeletal muscle resistance arteries (∼150 µm) of Zucker diabetic fatty (ZDF) rats and of their controls (+/Fa), exposed acutely to high glucose concentrations (HG, 25 mM, 1 h). AT(1) receptors on cell membrane surface were measured by immunofluorescence. KEY RESULTS Angiotensin II-induced constrictions to first applications were greater in arteries of ZDF rats (maximum: 82 ± 3% original diameter) than in those from +/Fa rats (61 ± 5%). Constrictions to repeated angiotensin II administration were decreased in +/Fa arteries (20 ± 6%), but were maintained in ZDF arteries (67 ± 4%) and in +/Fa arteries vessels exposed to HG (65 ± 6%). In ZDF arteries and in HG-exposed +/Fa arteries, Rho-kinase activities were enhanced. The Rho-kinase inhibitor, Y27632 inhibited sustained constrictions to angiotensin II in ZDF arteries and in +/Fa arteries exposed to HG. Levels of surface AT(1) receptors on cultured vascular smooth muscle cells (VSMCs) were decreased by angiotensin II but were maintained in VSMCs exposed to HG. In VSMCs exposed to HG and treated with Y27632, angiotensin II decreased surface AT(1) receptors. CONCLUSIONS AND IMPLICATIONS In diabetes, elevated glucose concentrations activate Rho-kinase which inhibits internalization or facilitates recycling of AT(1) receptors, leading to increased functional availability of AT(1) receptors and sustained angiotensin II-induced arterial constriction.
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Affiliation(s)
- Zsolt Bagi
- Department of Physiology, New York Medical College, Valhalla, NY, USA.
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15
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Endothelium-derived vasoactive agents, AT1 receptors and inflammation. Pharmacol Ther 2011; 131:187-203. [DOI: 10.1016/j.pharmthera.2010.11.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Accepted: 11/03/2010] [Indexed: 12/25/2022]
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16
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Ebrahimian T, Li MW, Lemarié CA, Simeone SMC, Pagano PJ, Gaestel M, Paradis P, Wassmann S, Schiffrin EL. Mitogen-activated protein kinase-activated protein kinase 2 in angiotensin II-induced inflammation and hypertension: regulation of oxidative stress. Hypertension 2010; 57:245-54. [PMID: 21173344 DOI: 10.1161/hypertensionaha.110.159889] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Vascular oxidative stress and inflammation play an important role in angiotensin II-induced hypertension, and mitogen-activated protein kinases participate in these processes. We questioned whether mitogen-activated protein kinase-activated protein kinase 2 (MK2), a downstream target of p38 mitogen-activated protein kinase, is involved in angiotensin II-induced vascular responses. In vivo experiments were performed in wild-type and Mk2 knockout mice infused intravenously with angiotensin II. Angiotensin II induced a 30 mm Hg increase in mean blood pressure in wild-type that was delayed in Mk2 knockout mice. Angiotensin II increased superoxide production and vascular cell adhesion molecule-1 in blood vessels of wild-type but not in Mk2 knockout mice. Mk2 knockdown by small interfering RNA in mouse mesenteric vascular smooth muscle cells caused a 42% reduction in MK2 protein and blunted the angiotensin II-induced 40% increase of MK2 expression. Mk2 knockdown blunted angiotensin II-induced doubling of intracellular adhesion molecule-1 expression, 2.4-fold increase of nuclear p65, and 1.4-fold increase in Ets-1. Mk2 knockdown abrogated the angiotensin II-induced 4.7-fold and 1.3-fold increase of monocyte chemoattractant protein-1 mRNA and protein. Angiotensin II enhanced reactive oxygen species levels (by 29%) and nicotinamide adenine dinucleotide phosphate oxidase activity (by 48%), both abolished by Mk2 knockdown. Reduction of MK2 blocked angiotensin II-induced p47phox translocation to the membrane, associated with a 53% enhanced catalase expression. Angiotensin II-induced increase of MK2 was prevented by the nicotinamide adenine dinucleotide phosphate oxidase inhibitor Nox2ds-tat. Mk2 small interfering RNA prevented the angiotensin II-induced 30% increase of proliferation. In conclusion, MK2 plays a critical role in angiotensin II signaling, leading to hypertension, oxidative stress via activation of p47phox and inhibition of antioxidants, and vascular inflammation and proliferation.
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Affiliation(s)
- Talin Ebrahimian
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, Montréal, Québec, Canada
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17
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Asico L, Zhang X, Jiang J, Cabrera D, Escano CS, Sibley DR, Wang X, Yang Y, Mannon R, Jones JE, Armando I, Jose PA. Lack of renal dopamine D5 receptors promotes hypertension. J Am Soc Nephrol 2010; 22:82-9. [PMID: 21051739 DOI: 10.1681/asn.2010050533] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Disruption of the dopamine D(5) receptor gene in mice increases BP and causes salt sensitivity. To determine the role of renal versus extrarenal D(5) receptors in BP regulation, we performed cross-renal transplantation experiments. BP was similar between wild-type mice and wild-type mice transplanted with wild-type kidneys, indicating that the transplantation procedure did not affect BP. BP was lower among D(5)(-/-) mice transplanted with wild-type kidneys than D(5)(-/-) kidneys, demonstrating that the renal D(5) receptors are important in BP control. BP was higher in wild-type mice transplanted with D(5)(-/-) kidneys than wild-type kidneys but not significantly different from syngenic transplanted D(5)(-/-) mice, indicating the importance of the kidney in the development of hypertension. On a high-salt diet, all mice with D(5)(-/-) kidneys excreted less sodium than mice with wild-type kidneys. Transplantation of a wild-type kidney into a D(5)(-/-) mouse decreased the renal expression of AT(1) receptors and Nox-2. Conversely, transplantation of a D(5)(-/-) kidney into a wild-type mouse increased the expression of both, suggesting that both renal and extrarenal factors are important in the regulation of AT(1) receptor and Nox-2 expression. These results highlight the role of renal D(5) receptors in BP homeostasis and the pathogenesis of hypertension.
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Affiliation(s)
- Laureano Asico
- Children's National Medical Center, Children's Research Institute, 111 Michigan Avenue NW, Washington, D.C., USA
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18
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Toth P, Koller A, Pusch G, Bosnyak E, Szapary L, Komoly S, Marko L, Nagy J, Wittmann I. Microalbuminuria, indicated by total versus immunoreactive urinary albumins, in acute ischemic stroke patients. J Stroke Cerebrovasc Dis 2010; 20:510-6. [PMID: 20813547 DOI: 10.1016/j.jstrokecerebrovasdis.2010.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 03/03/2010] [Accepted: 03/09/2010] [Indexed: 12/12/2022] Open
Abstract
Microalbuminuria, assessed by measuring immunoreactive albumin, is common in patients with cerebrovascular disease and is associated with increased risk of stroke. Total urinary albumin (t-uAlb) comprises both immunoreactive albumin (ir-uAlb) and nonimmunoreactive albumin (nir-uAlb). We hypothesized that t-uAlb is a more sensitive indicator of microalbuminuria than ir-uAlb, and that measurement of t-uAlb will increase the prevalence of microalbuminuria in ischemic stroke patients compared with measurement of ir-uAlb and will show a stronger correlation with the severity of stroke and oxidative stress. In urine samples from 98 patients with ischemic stroke, the albumin-to-creatinine ratios t-uAlb/uCreat and ir-uAlb/uCreat were measured by high-performance liquid chromatography (HPLC) and immunoturbidimetry (IT), and the nir-uAlb/uCreat ratio was calculated. Urinary ortho-tyrosine (o-Tyr/uCreat), an indicator of oxidative stress, was measured by HPLC. The severity of stroke was scored based on the National Institutes of Health Stroke Scale (NIHSS). The prevalence of microalbuminuria detected by HPLC was significantly higher than that detetcted by IT (66.3 vs 36.7%). Although all forms of albumin showed significant correlation with stroke severity (t-uAlb: r = 0.24, P < .05 ir-uAlb: r = 0.25, P < .05 nir-uAlb: r = 0.29, P < .05), only nir-uAlb was found to be an independent predictor of stroke severity (B = 0.20, β = 0.35, P < .05). In addition, t-uAlb/uCreat and nir-uAlb/uCreat had a significant correlation with o-Tyr/uCreat (r = 0.336, P < .05 and r = 0.358, P < .05 respectively), whereas ir-uAlb/uCreat did not (r = 0.22, P > .05). Our data suggest that in acute ischemic stroke patients, t-uAlb is a more sensitive indicator of microalbuminuria than the presently used ir-uAlb. Future studies should aim to elucidate the underlying mechanisms for the relationship among urinary albumins and cerebrovascular diseases and the role of urinary albumins in risk stratification for stroke.
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Affiliation(s)
- Peter Toth
- Department of Physiology, New York Medical College, Valhalla, New York, USA
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19
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Pereira AC, Olivon VC, de Oliveira AM. Impaired calcium influx despite hyper-reactivity in contralateral carotid following balloon injury: eNOS involvement. Eur J Pharmacol 2010; 642:121-7. [DOI: 10.1016/j.ejphar.2010.05.051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Revised: 03/25/2010] [Accepted: 05/06/2010] [Indexed: 11/24/2022]
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An Apparent Paradox: Attenuation of Phenylephrine-mediated Calcium Mobilization and Hyperreactivity to Phenylephrine in Contralateral Carotid After Balloon Injury. J Cardiovasc Pharmacol 2010; 56:162-70. [DOI: 10.1097/fjc.0b013e3181e571cd] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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