OBJECTIVE: We examined the effects of treatment with soluble epoxide hydrolase inhibitor (sEHi) and epoxyeicosatrienoic acids (EETs) analogue (EET-A), given alone or combined, on blood pressure (BP) and ischemia/reperfusion myocardial injury in rats with angiotensin II (ANG II)-dependent hypertension. METHODS: Ren-2 transgenic rats (TGR) were used as a model of ANG II-dependent hypertension and Hannover Sprague-Dawley rats served as controls. Rats were treated for 14 days with sEHi or EET-A and BP was measured by radiotelemetry. Albuminuria, cardiac hypertrophy and concentrations of ANG II and EETs were determined. Separate groups were subjected to acute myocardial ischemia/reperfusion injury and the infarct size and ventricular arrhythmias were determined. RESULTS: Treatment of TGR with sEHi and EET-A, given alone or combined, decreased BP to a similar degree, reduced albuminuria and cardiac hypertrophy to similar extent; only treatment regimens including sEHi increased myocardial and renal tissue concentrations of EETs. sEHi and EET-A, given alone or combined, suppressed kidney ANG II levels in TGR. Remarkably, infarct size did not significantly differ between TGR and Hannover Sprague-Dawley rats, but the incidence of ischemia-induced ventricular fibrillations was higher in TGR. Application of sEHi and EET-A given alone and combined sEHi and EET-A treatment were all equally effective in reducing life-threatening ventricular fibrillation in TGR. CONCLUSION: The findings indicate that chronic treatment with either sEHi or EET-A exerts distinct antihypertensive and antiarrhythmic actions in our ANG II-dependent model of hypertension whereas combined administration of sEHi and EET-A does not provide additive antihypertensive or cardioprotective effects.

• MeSH
• albuminurie metabolismus   MeSH
• angiotensin II metabolismus   MeSH
• antihypertenziva farmakologie   MeSH
• hypertenze metabolismus   MeSH
• krevní tlak účinky léků   MeSH
• krysa rodu rattus MeSH
• kyseliny arachidonové farmakologie   MeSH
• potkani Sprague-Dawley MeSH
• potkani transgenní MeSH
• srdeční arytmie metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Epoxyeicosatrienoic acids (EETs) decrease cardiac ischemia-reperfusion injury; however, the mechanism of their protective effect remains elusive. Here, we investigated the cardioprotective action of a novel EET analog, EET-B, in reperfusion and the role of hypoxia-inducible factor (HIF)-1α in such action of EET-B. Adult male rats were subjected to 30 min of left coronary artery occlusion followed by 2 h of reperfusion. Administration of 14,15-EET (2.5 mg/kg) or EET-B (2.5 mg/kg) 5 min before reperfusion reduced infarct size expressed as a percentage of the area at risk from 64.3 ± 1.3% in control to 42.6 ± 1.9% and 46.0 ± 1.6%, respectively, and their coadministration did not provide any stronger effect. The 14,15-EET antagonist 14,15-epoxyeicosa-5( Z)-enoic acid (2.5 mg/kg) inhibited the infarct size-limiting effect of EET-B (62.5 ± 1.1%). Similarly, the HIF-1α inhibitors 2-methoxyestradiol (2.5 mg/kg) and acriflavine (2 mg/kg) completely abolished the cardioprotective effect of EET-B. In a separate set of experiments, the immunoreactivity of HIF-1α and its degrading enzyme prolyl hydroxylase domain protein 3 (PHD3) were analyzed in the ischemic areas and nonischemic septa. At the end of ischemia, the HIF-1α immunogenic signal markedly increased in the ischemic area compared with the septum (10.31 ± 0.78% vs. 0.34 ± 0.08%). After 20 min and 2 h of reperfusion, HIF-1α immunoreactivity decreased to 2.40 ± 0.48% and 1.85 ± 0.43%, respectively, in the controls. EET-B blunted the decrease of HIF-1α immunoreactivity (7.80 ± 0.69% and 6.44 ± 1.37%, respectively) and significantly reduced PHD3 immunogenic signal in ischemic tissue after reperfusion. In conclusion, EET-B provides an infarct size-limiting effect at reperfusion that is mediated by HIF-1α and downregulation of its degrading enzyme PHD3. NEW & NOTEWORTHY The present study shows that EET-B is an effective agonistic 14,15-epoxyeicosatrienoic acid analog, and its administration before reperfusion markedly reduced myocardial infarction in rats. Most importantly, we demonstrate that increased hypoxia-inducible factor-1α levels play a role in cardioprotection mediated by EET-B in reperfusion likely by mechanisms including downregulation of the hypoxia-inducible factor -1α-degrading enzyme prolyl hydroxylase domain protein 3.

• MeSH
• down regulace MeSH
• faktor 1 indukovatelný hypoxií - podjednotka alfa genetika   metabolismus   MeSH
• funkce levé komory srdeční účinky léků   MeSH
• infarkt myokardu enzymologie   patologie   patofyziologie   prevence a kontrola   MeSH
• kyselina 8,11,14-eikosatrienová analogy a deriváty   farmakologie   MeSH
• modely nemocí na zvířatech MeSH
• myokard enzymologie   patologie   MeSH
• potkani Sprague-Dawley MeSH
• prolyl-4-hydroxylasy HIF genetika   metabolismus   MeSH
• proteolýza MeSH
• remodelace komor účinky léků   MeSH
• reperfuzní poškození myokardu enzymologie   patologie   patofyziologie   prevence a kontrola   MeSH
• signální transdukce účinky léků   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

BACKGROUND: Small renal arteries have a significant role in the regulation of renal hemodynamics and blood pressure (BP). To study potential changes in the regulation of vascular function in hypertension, we examined renal vasodilatory responses of small arteries from nonclipped kidneys of the 2-kidney, 1-clip Goldblatt hypertensive rats to native epoxyeicosatrienoic acids (EETs) that are believed to be involved in the regulation of renal vascular function and BP. A total of 2 newly synthesized EET analogues were also examined. MATERIALS AND METHODS: Renal interlobular arteries isolated from the nonclipped kidneys on day 28 after clipping were preconstricted with phenylephrine, pressurized and the effects of a 14,15-EET analogue, native 14,15-EET and 11,12-ether-EET-8ZE, an analogue of 11,12-EET, on the vascular diameter were determined and compared to the responses of arteries from the kidneys of sham-operated rats. RESULTS: In the arteries from nonclipped kidneys isolated in the maintenance phase of Goldblatt hypertension, the maximal vasodilatory response to 14,15-EET analogue was 30.1 ± 2.8% versus 49.8 ± 7.2% in sham-operated rats; the respective values for 11,12-ther-EET-8ZE were 31.4 ± 6.4% versus 80.4 ± 6%, and for native EETs they were 41.7 ± 6.6% versus 62.8 ± 4.4% (P ≤ 0.05 for each difference). CONCLUSIONS: We propose that reduced vasodilatory action and decreased intrarenal bioavailability of EETs combined with intrarenal angiotensin II levels that are inappropriately high for hypertensive rats underlie functional derangements of the nonclipped kidneys of 2-kidney, 1-clip Goldblatt hypertensive rats. These derangements could play an important role in pathophysiology of sustained BP elevation observed in this animal model of human renovascular hypertension.

• MeSH
• arteria renalis účinky léků   patofyziologie   MeSH
• krysa rodu rattus MeSH
• kyselina 8,11,14-eikosatrienová analogy a deriváty   farmakologie   MeSH
• ledviny krevní zásobení   patofyziologie   MeSH
• potkani Sprague-Dawley MeSH
• renovaskulární hypertenze farmakoterapie   MeSH
• vazodilatace účinky léků   MeSH
• vazodilatancia farmakologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Azilsartan medoxomil (AZL-M), an angiotensin II receptor blocker, demonstrates antihypertensive and organ protective effects in hypertension. We investigated the efficacy of AZL-M to ameliorate metabolic syndrome and kidney damage associated with type 2 diabetes using Zucker diabetic fatty (ZDF) rats. METHODS: ZDF rats were treated with vehicle or AZL-M for 8 weeks. Zucker diabetic lean (ZDL) rats were used as controls. Urine and plasma samples were collected for biochemical analysis, and kidney tissues were used for histopathological and immunohistopathological examination at the end of the 8-week protocol. RESULTS: ZDF rats were diabetic with hyperglycemia and impaired glucose tolerance, and AZL-M ameliorated the diabetic phenotype. ZDF rats were hypertensive compared with ZDL rats (181±6 vs. 129±7mm Hg), and AZL-M decreased blood pressure in ZDF rats (116±7mm Hg). In ZDF rats, there was marked renal damage with elevated proteinuria, albuminuria, nephrinuria, 2-4-fold higher tubular cast formation, and glomerular injury compared with ZDL rats. AZL-M treatment reduced renal damage in ZDF rats. ZDF rats demonstrated renal inflammation and oxidative stress with elevated urinary monocyte chemoattractant protein 1 excretion, renal infiltration of macrophages, and elevated kidney malondialdehyde levels. AZL-M reduced oxidative stress and inflammation in ZDF rats. CONCLUSIONS: Overall, we demonstrate that AZL-M attenuates kidney damage in type 2 diabetes. We further demonstrate that anti-inflammatory and antioxidative activities of AZL-M contribute to its kidney protective action.

• MeSH
• benzimidazoly terapeutické užití   MeSH
• blokátory receptoru 1 pro angiotenzin II terapeutické užití   MeSH
• cévní endotel účinky léků   MeSH
• diabetické nefropatie patologie   prevence a kontrola   MeSH
• glukózový toleranční test MeSH
• hyperglykemie farmakoterapie   MeSH
• krevní glukóza metabolismus   MeSH
• krevní tlak účinky léků   MeSH
• krysa rodu rattus MeSH
• oxadiazoly terapeutické užití   MeSH
• oxidační stres účinky léků   MeSH
• porucha glukózové tolerance prevence a kontrola   MeSH
• potkani Zucker MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Alterations in renal function contribute to Goldblatt two-kidney, one-clip (2K1C) hypertension. A previous study indicated that bioavailability of cytochrome P-450 metabolites epoxyeicosatrienoic acids (EETs) is decreased while that of 20-hydroxyeicosatetraenoic acids (20-HETE) is increased in this model. We utilized the inhibitor of soluble epoxide hydrolase cis-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (c-AUCB) and HET-0016, the inhibitor of 20-HETE production, to study the role of EETs and 20-HETE in the regulation of renal function. Chronic c-AUCB treatment significantly decreased systolic blood pressure (SBP) (133 ± 1 vs. 163 ± 3 mmHg) and increased sodium excretion (1.23 ± 0.10 vs. 0.59 ± 0.03 mmol/day) in 2K1C rats. HET-0016 did not affect SBP and sodium excretion. In acute experiments, renal blood flow (RBF) was decreased in 2K1C rats (5.0 ± 0.2 vs. 6.9 ± 0.2 ml·min(-1)·g(-1)). c-AUCB normalized RBF in 2K1C rats (6.5 ± 0.6 ml·min(-1)·g(-1)). HET-0016 also increased RBF in 2K1C rats (5.8 ± 0.2 ml·min(-1)·g(-1)). Although RBF and glomerular filtration rate (GFR) remained stable in normotensive rats during renal arterial pressure (RAP) reductions, both were significantly reduced at 100 mmHg RAP in 2K1C rats. c-AUCB did not improve autoregulation but increased RBF at all RAPs and shifted the pressure-natriuresis curve to the left. HET-0016-treated 2K1C rats exhibited impaired autoregulation of RBF and GFR. Our data indicate that c-AUCB displays antihypertensive properties in 2K1C hypertension that are mediated by an improvement of RBF and pressure natriuresis. While HET-0016 enhanced RBF, its anti-natriuretic effect likely prevented it from producing a blood pressure-lowering effect in the 2K1C model.

• MeSH
• amidiny farmakologie   MeSH
• epoxid hydrolasy antagonisté a inhibitory   MeSH
• inhibitory enzymů farmakologie   MeSH
• krevní tlak účinky léků   fyziologie   MeSH
• krysa rodu rattus MeSH
• kyseliny arachidonové metabolismus   MeSH
• kyseliny hydroxyeikosatetraenové metabolismus   MeSH
• ledviny krevní zásobení   účinky léků   fyziologie   MeSH
• modely nemocí na zvířatech MeSH
• regionální krevní průtok účinky léků   MeSH
• renovaskulární hypertenze metabolismus   patofyziologie   MeSH
• sodík moč   MeSH
• systém (enzymů) cytochromů P-450 metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH