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Li JC, Velagic A, Qin CX, Li M, Leo CH, Kemp-Harper BK, Ritchie RH, Woodman OL. Diabetes Attenuates the Contribution of Endogenous Nitric Oxide but Not Nitroxyl to Endothelium Dependent Relaxation of Rat Carotid Arteries. Front Pharmacol 2021; 11:585740. [PMID: 33716721 PMCID: PMC7944142 DOI: 10.3389/fphar.2020.585740] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 12/16/2020] [Indexed: 12/27/2022] Open
Abstract
Endothelial dysfunction is a major risk factor for several of the vascular complications of diabetes, including ischemic stroke. Nitroxyl (HNO), the one electron reduced and protonated form of nitric oxide (NO•), is resistant to scavenging by superoxide, but the role of HNO in diabetes mellitus associated endothelial dysfunction in the carotid artery remains unknown. Aim: To assess how diabetes affects the role of endogenous NO• and HNO in endothelium-dependent relaxation in rat isolated carotid arteries. Methods: Male Sprague Dawley rats were fed a high-fat-diet (HFD) for 2 weeks prior to administration of low dose streptozotocin (STZ; 35 mg/kg i. p./day) for 2 days. The HFD was continued for a further 12 weeks. Sham rats were fed standard chow and administered with citrate vehicle. After 14 weeks total, rats were anesthetized and carotid arteries collected to assess responses to the endothelium-dependent vasodilator, acetylcholine (ACh) by myography. The combination of calcium-activated potassium channel blockers, TRAM-34 (1 μmol/L) and apamin (1 μmol/L) was used to assess the contribution of endothelium-dependent hyperpolarization to relaxation. The corresponding contribution of NOS-derived nitrogen oxide species to relaxation was assessed using the combination of the NO• synthase inhibitor, L-NAME (200 μmol/L) and the soluble guanylate cyclase inhibitor ODQ (10 μmol/L). Lastly, L-cysteine (3 mmol/L), a selective HNO scavenger, and hydroxocobalamin (HXC; 100 μmol/L), a NO• scavenger, were used to distinguish between NO• and HNO-mediated relaxation. Results: At study end, diabetic rats exhibited significantly retarded body weight gain and elevated blood glucose levels compared to sham rats. The sensitivity and the maximal relaxation response to ACh was significantly impaired in carotid arteries from diabetic rats, indicating endothelial dysfunction. The vasorelaxation evoked by ACh was abolished by L-NAME plus ODQ, but not affected by the apamin plus TRAM-34 combination, indicating that NOS-derived nitrogen oxide species are the predominant endothelium-derived vasodilators in sham and diabetic rat carotid arteries. The maximum relaxation to ACh was significantly decreased by L-cysteine in both sham and diabetic rats, whereas HXC attenuated ACh-induced relaxation only in sham rats, suggesting that diabetes impaired the contribution of NO•, whereas HNO-mediated vasorelaxation remained intact. Conclusion: Both NO• and HNO contribute to endothelium-dependent relaxation in carotid arteries. In diabetes, NO•-mediated relaxation is impaired, whereas HNO-mediated relaxation was preserved. The potential for preserved HNO activity under pathological conditions that are associated with oxidative stress indicates that HNO donors may represent a viable therapeutic approach to the treatment of vascular dysfunction.
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Affiliation(s)
- Jasmin Chendi Li
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
- Department of Pharmacology, University of Melbourne, Parkville, VIC, Australia
| | - Anida Velagic
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Cheng Xue Qin
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
- Department of Pharmacology, University of Melbourne, Parkville, VIC, Australia
| | - Mandy Li
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Department of Pharmacology, Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Chen Huei Leo
- Science, Maths and Technology Cluster, Singapore University of Technology & Design, Singapore, Singapore
| | - Barbara K. Kemp-Harper
- Department of Pharmacology, Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Rebecca H. Ritchie
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
- Department of Pharmacology, University of Melbourne, Parkville, VIC, Australia
- Department of Pharmacology, Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Owen L. Woodman
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
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Pereira CA, Carneiro FS, Matsumoto T, Tostes RC. Bonus Effects of Antidiabetic Drugs: Possible Beneficial Effects on Endothelial Dysfunction, Vascular Inflammation and Atherosclerosis. Basic Clin Pharmacol Toxicol 2018; 123:523-538. [DOI: 10.1111/bcpt.13054] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 06/04/2018] [Indexed: 01/17/2023]
Affiliation(s)
- Camila A. Pereira
- Department of Pharmacology; Ribeirao Preto Medical School; University of Sao Paulo; Ribeirao Preto Brazil
| | - Fernando S. Carneiro
- Department of Pharmacology; Ribeirao Preto Medical School; University of Sao Paulo; Ribeirao Preto Brazil
| | - Takayuki Matsumoto
- Department of Physiology and Morphology; Institute of Medicinal Chemistry; Hoshi University; Shinagawa-ku Tokyo Japan
| | - Rita C. Tostes
- Department of Pharmacology; Ribeirao Preto Medical School; University of Sao Paulo; Ribeirao Preto Brazil
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Serelaxin treatment reverses vascular dysfunction and left ventricular hypertrophy in a mouse model of Type 1 diabetes. Sci Rep 2017; 7:39604. [PMID: 28067255 PMCID: PMC5220363 DOI: 10.1038/srep39604] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 11/24/2016] [Indexed: 12/20/2022] Open
Abstract
Serelaxin prevents endothelial dysfunction in the mouse aorta ex vivo and inhibits apoptosis in cardiomyocytes under acute hyperglycaemia. Less is known about the effects of serelaxin in an in vivo mouse model of diabetes. Therefore, we tested the hypothesis in streptozotocin (STZ)-treated mice that serelaxin is able to reverse diabetes-induced vascular dysfunction and cardiac remodelling. Mice were divided into citrate buffer + placebo, STZ + placebo and STZ + serelaxin (0.5 mg/kg/d, 2 weeks) groups. After 12 weeks of diabetes, sensitivity to the endothelium-dependent agonist acetylcholine (ACh) was reduced in the mesenteric artery. This was accompanied by an enhanced vasoconstrictor prostanoid contribution and a decrease in endothelium-derived hyperpolarisation (EDH)-mediated relaxation. Serelaxin restored endothelial function by increasing nitric oxide (NO)-mediated relaxation but not EDH. It also normalised the contribution of vasoconstrictor prostanoids to endothelial dysfunction and suppressed diabetes-induced hyper-responsiveness of the mesenteric artery to angiotensin II. Similarly, diabetes reduced ACh-evoked NO-mediated relaxation in the aorta which was reversed by serelaxin. In the left ventricle, diabetes promoted apoptosis, hypertrophy and fibrosis; serelaxin treatment reversed this ventricular apoptosis and hypertrophy, but had no effect on fibrosis. In summary, serelaxin reversed diabetes-induced endothelial dysfunction by enhancing NO-mediated relaxation in the mouse vasculature and attenuating left ventricular hypertrophy and apoptosis.
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Ishida K, Taguchi K, Hida M, Watanabe S, Kawano K, Matsumoto T, Hattori Y, Kobayashi T. Circulating microparticles from diabetic rats impair endothelial function and regulate endothelial protein expression. Acta Physiol (Oxf) 2016; 216:211-20. [PMID: 26235826 DOI: 10.1111/apha.12561] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 05/06/2015] [Accepted: 07/29/2015] [Indexed: 12/12/2022]
Abstract
AIM Diabetes mellitus increases the risk of cardiovascular disease, which is accompanied by functional and structural changes in the vascular system. Microparticles (MPs) have been described as biological vectors of endothelial dysfunction in other pathologies. However, the molecular mechanisms underlying their formation and signalling are unclear. We investigated the role of MPs derived from streptozotocin (STZ)-induced diabetic rats in endothelial function. METHODS Male Wistar rats were injected with STZ to induce diabetes, and MPs isolated from control or STZ-induced diabetic rats were characterized by dot blotting (assessed by CD62P detections), flow cytometry (assessed by annexin V detections) and ELISA. Carotid arteries from rats were incubated with MPs, and expressions of enzymes and endothelium-dependent relaxation were analysed. RESULTS The circulating levels of MPs, particularly the levels of platelet-derived microparticles, from diabetic rats were higher than those present in controls. Endothelium-dependent relaxation induced by acetylcholine (ACh) was attenuated in carotid arteries from STZ-induced diabetic rats. Following the incubation of control carotid arteries with MPs isolated from STZ rats, ACh-induced endothelium-dependent relaxation was impaired, but MPs isolated from control rats had no such effect. Furthermore, the effect of MPs was mediated by a decrease in expression of endothelial nitric oxide synthase (eNOS) and the overexpression of caveolin-1. CONCLUSION Circulating MPs isolated from STZ-induced diabetic rats induce endothelial dysfunction in carotid arteries and regulate protein expressions of eNOS and caveolin-1. These data advance our understanding of the deleterious effects of circulating MPs observed in disorders with diabetic complications.
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Affiliation(s)
- K. Ishida
- Department of Physiology and Morphology; Institute of Medicinal Chemistry; Hoshi University; Tokyo Japan
| | - K. Taguchi
- Department of Physiology and Morphology; Institute of Medicinal Chemistry; Hoshi University; Tokyo Japan
| | - M. Hida
- Department of Physiology and Morphology; Institute of Medicinal Chemistry; Hoshi University; Tokyo Japan
| | - S. Watanabe
- Department of Physiology and Morphology; Institute of Medicinal Chemistry; Hoshi University; Tokyo Japan
| | - K. Kawano
- Institute of Medicinal Chemistry; Hoshi University; Tokyo Japan
| | - T. Matsumoto
- Department of Physiology and Morphology; Institute of Medicinal Chemistry; Hoshi University; Tokyo Japan
| | - Y. Hattori
- Institute of Medicinal Chemistry; Hoshi University; Tokyo Japan
| | - T. Kobayashi
- Department of Physiology and Morphology; Institute of Medicinal Chemistry; Hoshi University; Tokyo Japan
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Activated platelets from diabetic rats cause endothelial dysfunction by decreasing Akt/endothelial NO synthase signaling pathway. PLoS One 2014; 9:e102310. [PMID: 25047034 PMCID: PMC4105471 DOI: 10.1371/journal.pone.0102310] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 06/17/2014] [Indexed: 01/08/2023] Open
Abstract
Diabetes is associated with endothelial dysfunction and platelet activation, both of which may contribute to increased cardiovascular risk. The purpose of this study was to characterize circulating platelets in diabetes and clarify their effects on endothelial function. Male Wistar rats were injected with streptozotocin (STZ) to induce diabetes. Each experiment was performed by incubating carotid arterial rings with platelets (1.65×107 cells/mL; 30 min) isolated from STZ or control rats. Thereafter, the vascular function was characterized in isolated carotid arterial rings in organ bath chambers, and each expression and activation of enzymes involved in nitric oxide and oxidative stress levels were analyzed. Endothelium-dependent relaxation induced by acetylcholine was significantly attenuated in carotid arteries treated with platelets isolated from STZ rats. Similarly, treatment with platelets isolated from STZ rats significantly reduced ACh-induced Akt/endothelial NO synthase signaling/NO production and enhanced TXB2 (metabolite of TXA2), while CD61 (platelet marker) and CD62P (activated platelet marker) were increased in carotid arteries treated with platelets isolated from STZ rats. Furthermore, the platelets isolated from STZ rats decreased total eNOS protein and eNOS dimerization, and increased oxidative stress. These data provide direct evidence that circulating platelets isolated from diabetic rats cause dysfunction of the endothelium by decreasing NO production (via Akt/endothelial NO synthase signaling pathway) and increasing TXA2. Moreover, activated platelets disrupt the carotid artery by increasing oxidative stress.
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Gokina NI, Bonev AD, Gokin AP, Goloman G. Role of impaired endothelial cell Ca(2+) signaling in uteroplacental vascular dysfunction during diabetic rat pregnancy. Am J Physiol Heart Circ Physiol 2013; 304:H935-45. [PMID: 23376827 DOI: 10.1152/ajpheart.00513.2012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Diabetes mellitus in pregnancy is associated with impaired endothelium-mediated dilatation of maternal arteries, although the underlying cellular mechanisms remain unknown. In this study, we hypothesized that diabetes during rat gestation attenuates agonist-induced uterine vasodilation through reduced endothelial cell (EC) Ca(2+) elevations and impaired smooth muscle cell (SMC) hyperpolarization and SMC intracellular Ca(2+) concentration ([Ca(2+)]i) responses. Diabetes was induced by an injection of streptozotocin to second-day pregnant rats and confirmed by the development of maternal hyperglycemia. Control rats were injected with a citrate buffer. Fura-2-based measurements of SMC [Ca(2+)]i or microelectrode recordings of SMC membrane potential were performed concurrently with dilator responses to ACh in uteroplacental arteries from control and diabetic pregnant rats. Basal levels of EC [Ca(2+)]i and ACh-induced EC [Ca(2+)]i elevations in pressurized vessels and small EC sheets were studied as well. Diabetes reduced ACh-induced vasodilation due to a markedly impaired EDHF-mediated response. Diminished vasodilation to ACh was associated with attenuated SMC hyperpolarization and [Ca(2+)]i responses. Basal levels of EC [Ca(2+)]i and ACh-induced EC [Ca(2+)]i elevations were significantly reduced by diabetes. In conclusion, these data demonstrate that reduced endothelium-mediated hyperpolarization contributes to attenuated uteroplacental vasodilation and SMC [Ca(2+)]i responses to ACh in diabetic pregnancy. Impaired endothelial Ca(2+) signaling is in part responsible for endothelial dysfunction in the uterine resistance vasculature of diabetic rats. Pharmacological improvement of EC Ca(2+) handling may provide an important strategy for the restoration of endothelial function and enhancement of maternal blood flow in human pregnancies complicated by diabetes.
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Affiliation(s)
- Natalia I Gokina
- Department of Obstetrics, Gynecology, and Reproductive Sciences, College of Medicine, University of Vermont, Burlington, VT 05405, USA.
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Delbin MA, Davel APC, Couto GK, de Araújo GG, Rossoni LV, Antunes E, Zanesco A. Interaction between advanced glycation end products formation and vascular responses in femoral and coronary arteries from exercised diabetic rats. PLoS One 2012; 7:e53318. [PMID: 23285277 PMCID: PMC3532341 DOI: 10.1371/journal.pone.0053318] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 11/29/2012] [Indexed: 01/28/2023] Open
Abstract
Background The majority of studies have investigated the effect of exercise training (TR) on vascular responses in diabetic animals (DB), but none evaluated nitric oxide (NO) and advanced glycation end products (AGEs) formation associated with oxidant and antioxidant activities in femoral and coronary arteries from trained diabetic rats. Our hypothesis was that 8-week TR would alter AGEs levels in type 1 diabetic rats ameliorating vascular responsiveness. Methodology/Principal Findings Male Wistar rats were divided into control sedentary (C/SD), sedentary diabetic (SD/DB), and trained diabetic (TR/DB). DB was induced by streptozotocin (i.p.: 60 mg/kg). TR was performed for 60 min per day, 5 days/week, during 8 weeks. Concentration-response curves to acetylcholine (ACh), sodium nitroprusside (SNP), phenylephrine (PHE) and tromboxane analog (U46619) were obtained. The protein expressions of eNOS, receptor for AGEs (RAGE), Cu/Zn-SOD and Mn-SOD were analyzed. Tissues NO production and reactive oxygen species (ROS) generation were evaluated. Plasma nitrate/nitrite (NOx−), superoxide dismutase (SOD), catalase (CAT), thiobarbituric acid reactive substances (TBARS) and Nε-(carboxymethyl) lysine (CML, AGE biomarker). A rightward shift in the concentration-response curves to ACh was observed in femoral and coronary arteries from SD/DB that was accompanied by an increase in TBARS and CML levels. Decreased in the eNOS expression, tissues NO production and NOx− levels were associated with increased ROS generation. A positive interaction between the beneficial effect of TR on the relaxing responses to ACh and the reduction in TBARS and CML levels were observed without changing in antioxidant activities. The eNOS protein expression, tissues NO production and ROS generation were fully re-established in TR/DB, but plasma NOx− levels were partially restored. Conclusion Shear stress induced by TR fully restores the eNOS/NO pathway in both preparations from non-treated diabetic rats, however, a massive production of AGEs still affecting relaxing responses possibly involving other endothelium-dependent vasodilator agents, mainly in coronary artery.
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MESH Headings
- Animals
- Antioxidants/metabolism
- Antioxidants/pharmacology
- Coronary Vessels/drug effects
- Coronary Vessels/metabolism
- Coronary Vessels/physiopathology
- Diabetes Mellitus, Experimental/chemically induced
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/physiopathology
- Diabetes Mellitus, Experimental/therapy
- Dose-Response Relationship, Drug
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/physiopathology
- Endothelium-Dependent Relaxing Factors/metabolism
- Endothelium-Dependent Relaxing Factors/pharmacology
- Femoral Artery/drug effects
- Femoral Artery/metabolism
- Femoral Artery/physiopathology
- Glycation End Products, Advanced/metabolism
- Glycation End Products, Advanced/pharmacology
- Male
- Physical Conditioning, Animal
- Rats
- Rats, Wistar
- Reactive Oxygen Species/metabolism
- Reactive Oxygen Species/pharmacology
- Streptozocin
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Affiliation(s)
- Maria A. Delbin
- Department of Physical Education, Institute of Bioscience, University of São Paulo State (UNESP), Rio Claro, São Paulo, Brazil
| | - Ana Paula C. Davel
- Department of Anatomy, Cellular Biology, Physiology and Biophysics, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Gisele Kruger Couto
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, São Paulo, Brazil
| | - Gustavo G. de Araújo
- Department of Physical Education, Institute of Bioscience, University of São Paulo State (UNESP), Rio Claro, São Paulo, Brazil
| | - Luciana Venturini Rossoni
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, São Paulo, Brazil
| | - Edson Antunes
- Department of Pharmacology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Angelina Zanesco
- Department of Physical Education, Institute of Bioscience, University of São Paulo State (UNESP), Rio Claro, São Paulo, Brazil
- * E-mail:
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Oniki H, Goto K, Fujii K, Kansui Y, Murakami N, Ohtsubo T, Matsumura K, Kitazono T. Effects of the superoxide dismutase mimetic tempol on impaired endothelium-dependent and endothelium-independent relaxations in type II diabetic rats. Clin Exp Hypertens 2012; 35:112-9. [PMID: 22783963 DOI: 10.3109/10641963.2012.702829] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Endothelium-derived hyperpolarizing factor (EDHF)-mediated hyperpolarization and relaxation, and endothelium-independent relaxations to the nitric oxide donor sodium nitroprusside and the adenosine 5'-triphosphate (ATP)-sensitive K(+)-channel opener levcromakalim were both impaired in mesenteric arteries of type II diabetic Goto-Kakizaki rats. The treatment with the superoxide dismutase mimetic tempol or its combination with the angiotensin II type 1 receptor blocker candesartan failed to improve EDHF-mediated responses, although both treatments partially improved endothelium-independent relaxations. These findings suggest that increased oxidative stress may in part account for the impaired endothelium-independent relaxations in diabetes, while it does not play a major role in the impaired EDHF-mediated responses.
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Affiliation(s)
- Hideyuki Oniki
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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Félétou M. The Endothelium, Part I: Multiple Functions of the Endothelial Cells -- Focus on Endothelium-Derived Vasoactive Mediators. ACTA ACUST UNITED AC 2011. [DOI: 10.4199/c00031ed1v01y201105isp019] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Gao X, Martinez-Lemus LA, Zhang C. Endothelium-derived hyperpolarizing factor and diabetes. World J Cardiol 2011; 3:25-31. [PMID: 21286215 PMCID: PMC3030734 DOI: 10.4330/wjc.v3.i1.25] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 11/30/2010] [Accepted: 12/07/2010] [Indexed: 02/06/2023] Open
Abstract
In addition to its role as a barrier between blood and tissues, the vascular endothelium is responsible for the synthesis and released of a number of vasodilators including prostaglandins, nitric oxide and endothelium-derived hyperpolarizing factor (EDHF). As one of these vasodilators, the specific nature of EDHF has not been fully elucidated, although a number of roles have been proposed. Importantly, many conditions, such as hypertension, hyperlipidemia, heart failure, ischemia-reperfusion and diabetes mellitus comprise vascular endothelial dysfunction with EDHF dysregulation. This article reviews reports on the role of EDHF in diabetes-related endothelial dysfunction.
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Affiliation(s)
- Xue Gao
- Xue Gao, Department of Physiology, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100005, China
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Matsumoto T, Kobayashi T, Ishida K, Hirasawa Y, Morita H, Honda T, Kamata K. Vasodilator effect of Cassiarin A, a novel antiplasmodial alkaloid from Cassia siamea, in rat isolated mesenteric artery. Biol Pharm Bull 2010; 33:844-8. [PMID: 20460764 DOI: 10.1248/bpb.33.844] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to investigate the vasorelaxant effect induced by cassiarin A, a novel antiplasmodial alkaloid from Cassia siamea, in rings cut from rat superior mesenteric arteries. In rings precontracted with phenylephrine, cassiarin A induced a concentration-dependent relaxation. This relaxation was attenuated: 1) after removal of the endothelium or after pretreatment of rings with 100 microM of N(G)-nitro-L-arginine (nitric oxide synthase inhibitor) or 10 microM of 1H-[1,2,4]oxadiazolo[4,3-a]-quinoxalin-1-one (guanylyl cyclase inhibitor), but not after pretreatment with 10 microM of indomethacin (cyclooxygenase inhibitor); and 2) after pretreatment of preparations with either a nonselective or selective inhibitor of large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels [1 mM of tetraethylammonium or 100 nM of iberiotoxin, respectively]. The cassiarin A-induced relaxation was also attenuated by these BK(Ca) inhibitors in endothelium-denuded preparations. The cassiarin A-induced relaxation was not altered by treatment with the ATP-sensitive K(+)-channel inhibitor glibenclamide (10 microM) or with the voltage-dependent K(+)-channel inhibitor 4-aminopyridine (1 mM). In isolated mesenteric artery rings, cassiarin A tended to increase nitric oxide (NO) levels. These results suggest that in the rat mesenteric artery, cassiarin A-induced relaxation may be mediated by endothelial NO and may occur partly via BK(Ca)-channel activation.
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Affiliation(s)
- Takayuki Matsumoto
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo 142-8501, Japan
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Gupte RS, Floyd BC, Kozicky M, George S, Ungvari ZI, Neito V, Wolin MS, Gupte SA. Synergistic activation of glucose-6-phosphate dehydrogenase and NAD(P)H oxidase by Src kinase elevates superoxide in type 2 diabetic, Zucker fa/fa, rat liver. Free Radic Biol Med 2009; 47:219-28. [PMID: 19230846 PMCID: PMC2700195 DOI: 10.1016/j.freeradbiomed.2009.01.028] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 01/02/2009] [Accepted: 01/18/2009] [Indexed: 10/21/2022]
Abstract
Glucose metabolism through the glycolysis and hexosamine pathway has been shown to be altered in type 2 diabetes. However, the fate of glucose through the pentose phosphate pathway (PPP) is currently unclear. In this study, we determined whether the activity of glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme in the PPP, is modulated in the liver of Zucker obese fa/fa rats (9-11 weeks of age). We found that G6PD expression and activity, NADPH levels, and 6-phosphogluconate generation were significantly increased in the liver of fa/fa rats. Inhibition of PI3 kinase and Src kinases decreased (p < 0.05) G6PD activity in the fa/fa but not in the lean rat liver, suggesting that G6PD activity is regulated by PI3/Src kinase signaling pathways. G6PD-derived NADPH increased (p < 0.05) superoxide anion levels by 70-90% in fa/fa vs lean rat liver, which was inhibited by the NADPH oxidase inhibitor gp91(ds-tat) (50 microM) and G6PD inhibitors 6-aminonicotinamide (1 mM) and dehydroepiandrosterone (100 microM), therefore indicating that elevated G6PD activity may be responsible for mediating superoxide generation. Interestingly, we also found a positive correlation between liver hypertrophy/increased G6PD activity (r2 = 0.77; p = 0.0009) and liver hypertrophy/superoxide production (r2 = 0.51; p = 0.0091) in fa/fa rats. Increased G6PD and NADPH oxidase expression and activity, in young hyperglycemic and hyperinsulinemic rats before the development of diabetes, seems to be a contributing factor in the induction of oxidative stress. Because inhibition of G6PD activity decreases oxidative stress, we conclude that G6PD behaves as a pro-oxidant in the fa/fa rat liver in type 2 diabetes.
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Affiliation(s)
- Rakhee S. Gupte
- Department of Biochemistry & Molecular Biology, University of South Alabama, Mobile, AL 36688
- Department of Physiology, New York Medical College, Valhalla, NY 10595
| | - Beverly C. Floyd
- Department of Physiology, New York Medical College, Valhalla, NY 10595
| | - Mark Kozicky
- Department of Physiology, New York Medical College, Valhalla, NY 10595
| | - Shimran George
- Department of Physiology, New York Medical College, Valhalla, NY 10595
| | - Zoltan I. Ungvari
- Department of Physiology, New York Medical College, Valhalla, NY 10595
| | - Vanessa Neito
- Department of Physiology, New York Medical College, Valhalla, NY 10595
| | - Michael S. Wolin
- Department of Physiology, New York Medical College, Valhalla, NY 10595
| | - Sachin A Gupte
- Department of Biochemistry & Molecular Biology, University of South Alabama, Mobile, AL 36688
- Department of Physiology, New York Medical College, Valhalla, NY 10595
- Address Correspondence to: Sachin A Gupte, MD, PhD, Department of Biochemistry & Molecular Biology, University of South Alabama, College of Medicine, 307 University Blvd N., Mobile, AL 36688, USA, Tel: (251) 460-6402; Fax: (251) 460-6850,
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Serpillon S, Floyd BC, Gupte RS, George S, Kozicky M, Neito V, Recchia F, Stanley W, Wolin MS, Gupte SA. Superoxide production by NAD(P)H oxidase and mitochondria is increased in genetically obese and hyperglycemic rat heart and aorta before the development of cardiac dysfunction. The role of glucose-6-phosphate dehydrogenase-derived NADPH. Am J Physiol Heart Circ Physiol 2009; 297:H153-62. [PMID: 19429815 DOI: 10.1152/ajpheart.01142.2008] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Increased oxidative stress is a known cause of cardiac dysfunction in animals and patients with diabetes, but the sources of reactive oxygen species [e.g., superoxide anion (O(2)(-))] and the mechanisms underlying O(2)(-) production in diabetic hearts are not clearly understood. Our aim was to determine whether NADPH oxidase (Nox) is a source of O(2)(-) and whether glucose-6-phosphate dehydrogenase (G6PD)-derived NADPH plays a role in augmenting O(2)(-) generation in diabetes. We assessed cardiac function, Nox and G6PD activities, NADPH levels, and the activities of antioxidant enzymes in heart homogenates from young (9-11 wk old) Zucker lean and obese (fa/fa) rats. We found that myocardial G6PD activity was significantly higher in fa/fa than in lean rats, whereas superoxide dismutase and glutathione peroxidase activities were decreased (P < 0.05). O(2)(-) levels were elevated (70-90%; P < 0.05) in the diabetic heart, and this elevation was blocked by the Nox inhibitor gp-91(ds-tat) (50 microM) or by the mitochondrial respiratory chain inhibitors antimycin (10 microM) and rotenone (50 microM). Inhibition of G6PD by 6-aminonicotinamide (5 mM) and dihydroepiandrosterone (100 microM) also reduced (P < 0.05) O(2)(-) production. Notably, the activities of Nox and G6PD in the fa/fa rat heart were inhibited by chelerythrine, a protein kinase C inhibitor. Although we detected no changes in stroke volume, cardiac output, or ejection fraction, left ventricular diameter was slightly increased during diastole and systole, and left ventricular posterior wall thickness was decreased during systole (P < 0.05) in Zucker fa/fa rats. Our findings suggest that in a model of severe hyperlipidema and hyperglycemia Nox-derived O(2)(-) generation in the myocardium is fueled by elevated levels of G6PD-derived NADPH. Similar mechanisms were found to activate O(2)(-) production and induce endothelial dysfunction in aorta. Thus G6PD may be a useful therapeutic target for treating the cardiovascular disease associated with type 2 diabetes, if second-generation drugs specifically reducing the activity of G6PD to near normal levels are developed.
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Affiliation(s)
- Sabrina Serpillon
- Department of Physiology, New York Medical College, Valhalla, NY, USA
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Kamata K, Kobayashi T, Matsumoto T, Kanie N, Oda SI, Kaneda A, Sugiura M. Effects of Chronic Administration of Fruit Extract (Citrus unshiu MARC) on Endothelial Dysfunction in Streptozotocin-Induced Diabetic Rats. Biol Pharm Bull 2005; 28:267-70. [PMID: 15684481 DOI: 10.1248/bpb.28.267] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We investigated the effects of chronic administration of fruit extract (Citrus unshiu MARC) on the endothelial dysfunction seen in aortae from streptozotocin (STZ)-induced diabetic rats. A ten-week administration of this fruit extract preserved acetylcholine (ACh)-induced endothelium-dependent relaxation, but not sodium nitroprusside (SNP)-induced endothelium-independent relaxation, in the diabetic aorta. In age-matched control rats, chronic administration of the fruit extract had no influence on the ACh- or SNP-induced aortic relaxation. The increased total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride levels seen in STZ-induced diabetic rats were not normalized by fruit-extract treatment. These results suggest that Citrus unshiu MARC extract preserves endothelial function in the aorta in STZ-induced diabetic rats without lowering plasma cholesterol. This beneficial effect may be due to this extract protecting of nitric oxide against inactivation by oxygen free radicals.
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Affiliation(s)
- Katsuo Kamata
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo 142-8501, Japan.
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16
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Loichot C, Anjuère J, Nisato D, De Jong W, Imbs JL, Barthelmebs M. Renal vascular reactivity to vasopressin in rats with diabetes mellitus. Eur J Pharmacol 2001; 431:321-9. [PMID: 11730725 DOI: 10.1016/s0014-2999(01)01404-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We evaluated how renal vascular reactivity to vasopressin changes when nitric oxide (NO) synthesis varies, as has been reported to occur in the course of insulin-dependent diabetes mellitus. Renal vasoconstrictor responses to vasopressin were obtained in young and older Sprague-Dawley control rats (3 and 10 months old) and in age-matched diabetic rats that had been treated with streptozotocin (60 mg/kg i.v.) at the age of 2 months. In young rats, vasopressin (3-1000 ng/kg/min i.v.) induced in vivo a dose-dependent decrease in renal blood flow, which was diminished in streptozotocin diabetic rats (P<0.05). Similarly, in in vitro perfused kidneys, the concentration-response curve for vasopressin (0.03-10 nM) was shifted 3-fold to the right in kidneys isolated from young diabetic rats (P<0.05). This shift was abolished in the presence of an inhibitor of nitric oxide synthesis, N(G)-nitro-L-arginine (100 microM), in the perfusate. In 10-month-old rats, the in vivo renal vasoconstrictor dose-response curve to vasopressin was shifted 10-fold to the left as compared to that for young rats (P<0.001). This shift was similar in both control and diabetic rats. In conclusion, the present study documented the existence of hyporesponsiveness to vasopressin in the early stage of diabetes, possibly related to nitric oxide overproduction. In contrast, renal vascular hyperreactivity to vasopressin occurs with aging, whether the rats are diabetic or not.
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Affiliation(s)
- C Loichot
- Institut de Pharmacologie, Faculté de Médecine, 11 Rue Humann, 67085 Strasbourg Cedex, France
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