The aim was to evaluate the effects of renal denervation (RDN) on autoregulation of renal hemodynamics and the pressure-natriuresis relationship in Ren-2 transgenic rats (TGR) with aorto-caval fistula (ACF)-induced heart failure (HF). RDN was performed one week after creation of ACF or sham-operation. Animals were prepared for evaluation of autoregulatory capacity of renal blood flow (RBF) and glomerular filtration rate (GFR), and of the pressure-natriuresis characteristics after stepwise changes in renal arterial pressure (RAP) induced by aortic clamping. Their basal values of blood pressure and renal function were significantly lower than with innervated sham-operated TGR (p < 0.05 in all cases): mean arterial pressure (MAP) (115 ± 2 vs. 160 ± 3 mmHg), RBF (6.91 ± 0.33 vs. 10.87 ± 0.38 ml.min-1.g-1), urine flow (UF) (11.3 ± 1.79 vs. 43.17 ± 3.24 µl.min-1.g-1) and absolute sodium excretion (UNaV) (1.08 ± 0.27 vs, 6.38 ± 0.76 µmol.min-1.g-1). After denervation ACF TGR showed improved autoregulation of RBF: at lowest RAP level (80 mmHg) the value was higher than in innervated ACF TGR (6.92 ± 0.26 vs. 4.54 ± 0.22 ml.min-1.g-1, p < 0.05). Also, the pressure-natriuresis relationship was markedly improved after RDN: at the RAP of 80 mmHg UF equaled 4.31 ± 0.99 vs. 0.26 ± 0.09 µl.min-1.g-1 recorded in innervated ACF TGR, UNaV was 0.31 ± 0.05 vs. 0.04 ± 0.01 µmol min-1.g-1 (p < 0.05 in all cases). In conclusion, in our model of hypertensive rat with ACF-induced HF, RDN improved autoregulatory capacity of RBF and the pressure-natriuresis relationship when measured at the stage of HF decompensation.

• Klíčová slova
• Ren-2 transgenic hypertensive rat, Renal autoregulation, Renal blood flow, Volume-overload heart failure, sodium excretion,
• MeSH
• hodnoty glomerulární filtrace MeSH
• hypertenze * MeSH
• kardiorenální syndrom * MeSH
• krevní tlak MeSH
• krysa rodu Rattus MeSH
• ledviny MeSH
• natriuréza MeSH
• píštěle * MeSH
• potkani transgenní MeSH
• renální oběh MeSH
• srdeční selhání * MeSH
• sympatektomie MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The aim of the present study was to assess the autoregulatory capacity of renal blood flow (RBF) and of the pressure-natriuresis characteristics in the early phase of heart failure (HF) in rats, normotensive and with angiotensin II (ANG II)-dependent hypertension. Ren-2 transgenic rats (TGR) were employed as a model of ANG II-dependent hypertension. HF was induced by creating the aorto-caval fistula (ACF). One week after ACF creation or sham-operation, the animals were prepared for studies evaluating in vivo RBF autoregulatory capacity and the pressure-natriuresis characteristics after stepwise changes in renal arterial pressure (RAP) induced by aortic clamping. In ACF TGR the basal mean arterial pressure, RBF, urine flow (UF), and absolute sodium excretion (UNaV) were all significantly lower tha n in sham-operated TGR. In the latter, reductions in renal arterial pressure (RAP) significantly decreased RBF whereas in ACF TGR they did not change. Stepwise reductions in RAP resulted in marked decreases in UF and UNaV in sham-operated as well as in ACF TGR, however, these decreases were significantly greater in the former. Our data show that compared with sham-operated TGR, ACF TGR displayed well-maintained RBF autoregulatory capacity and improved slope of the pressure-natriuresis relationship. Thus, even though in the very early HF stage renal dysfunction was demonstrable, in the HF model of ANG II-dependent hypertensive rat such dysfunction and the subsequent HF decompensation cannot be simply ascribed to impaired renal autoregulation and pressure-natriuresis relationship.

• Klíčová slova
• Ren-2 transgenic hypertensive rat, Renal autoregulation, Renal blood flow, Sodium excretion, Volume-overload heart failure,
• MeSH
• angiotensin II farmakologie   MeSH
• homeostáza MeSH
• hypertenze * MeSH
• krevní tlak MeSH
• krysa rodu Rattus MeSH
• ledviny MeSH
• natriuréza MeSH
• potkani transgenní MeSH
• renální oběh MeSH
• sodík MeSH
• srdeční selhání * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• angiotensin II MeSH
• sodík MeSH

Epoxyeicosatrienoic acids (EETs) are also known as epoxyeicosanoids that have renal and cardiovascular actions. These renal and cardiovascular actions can be regulated by soluble epoxide hydrolase (sEH) that degrades and inactivates EETs. Extensive animal hypertension studies have determined that vascular, epithelial transport, and anti-inflammatory actions of EETs lower blood pressure and decrease renal and cardiovascular disease progression. Human studies have also supported the notion that increasing EET levels in hypertension could be beneficial. Pharmacological and genetic approaches to increase epoxyeicosanoids in several animal models and humans have found improved endothelial vascular function, increased sodium excretion, and decreased inflammation to oppose hypertension and associated renal and cardiovascular complications. These compelling outcomes support the concept that increasing epoxyeicosanoids via sEH inhibitors or EET analogs could be a valuable hypertension treatment.

• MeSH
• antihypertenziva terapeutické užití   MeSH
• epoxid hydrolasy antagonisté a inhibitory   metabolismus   MeSH
• hypertenze farmakoterapie   metabolismus   patofyziologie   MeSH
• ikosanoidy metabolismus   terapeutické užití   MeSH
• inhibitory enzymů terapeutické užití   MeSH
• krevní tlak účinky léků   MeSH
• lidé MeSH
• signální transdukce MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• antihypertenziva MeSH
• epoxid hydrolasy MeSH
• ikosanoidy MeSH
• inhibitory enzymů MeSH

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
• Názvy látek
• angiotensin II MeSH
• antihypertenziva MeSH
• kyseliny arachidonové MeSH

BACKGROUND/AIMS: We found recently that increasing renal epoxyeicosatrienoic acids (EETs) levels by blocking soluble epoxide hydrolase (sEH), an enzyme responsible for EETs degradation, shows renoprotective actions and retards the progression of chronic kidney disease (CKD) in Ren-2 transgenic hypertensive rats (TGR) after 5/6 renal ablation (5/6 NX). This prompted us to examine if additional protection is provided when sEH inhibitor is added to the standard renin-angiotensin system (RAS) blockade, specifically in rats with established CKD. METHODS: For RAS blockade, an angiotensin-converting enzyme inhibitor along with an angiotensin II type receptor blocker was used. RAS blockade was compared to sEH inhibition added to the RAS blockade. Treatments were initiated 6 weeks after 5/6 NX in TGR and the follow-up period was 60 weeks. RESULTS: Combined RAS and sEH blockade exhibited additional positive impact on the rat survival rate, further reduced albuminuria, further reduced glomerular and tubulointerstitial injury, and attenuated the decline in creatinine clearance when compared to 5/6 NX TGR subjected to RAS blockade alone. These additional beneficial actions were associated with normalization of the intrarenal EETs deficient and a further reduction of urinary angiotensinogen excretion. CONCLUSION: This study provides evidence that addition of pharmacological inhibition of sEH to RAS blockade in 5/6 NX TGR enhances renoprotection and retards progression of CKD, notably, when applied at an advanced stage.

• Klíčová slova
• 5/6 nephrectomy, Chronic kidney disease, Epoxyeicosatrienoic acids, Hypertension, Renin-angiotensin system, Soluble epoxide hydrolase,
• MeSH
• albuminurie farmakoterapie   MeSH
• chronická renální insuficience farmakoterapie   mortalita   patofyziologie   chirurgie   MeSH
• epoxid hydrolasy antagonisté a inhibitory   MeSH
• hypertenze MeSH
• inhibitory ACE terapeutické užití   MeSH
• kombinovaná farmakoterapie MeSH
• krysa rodu Rattus MeSH
• míra přežití MeSH
• nefrektomie MeSH
• potkani transgenní MeSH
• renin-angiotensin systém účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• epoxid hydrolasy MeSH
• inhibitory ACE MeSH

OBJECTIVE: We evaluated the therapeutic effectiveness of a new, orally active epoxyeicosatrienoic acid analog (EET-A) in rats with angiotensin II (ANG II)-dependent malignant hypertension. METHODS: Malignant hypertension was induced in Cyp1a1-Ren-2 transgenic rats by activation of the renin gene using indole-3-carbinol (I3C), a natural xenobiotic. EET-A treatment was started either simultaneously with I3C induction process (early treatment) or 10 days later during established hypertension (late treatment). Blood pressure (BP) (radiotelemetry), indices of renal and cardiac injury, and plasma and kidney levels of the components of the renin-angiotensin system (RAS) were determined. RESULTS: In I3C-induced hypertensive rats, early EET-A treatment attenuated BP increase (to 175 ± 3 versus 193 ± 4 mmHg, P < 0.05, on day 13), reduced albuminuria (15 ± 1 versus 28 ± 2 mg/24 h, P < 0.05), and cardiac hypertrophy as compared with untreated I3C-induced rats. This was associated with suppression of plasma and kidney ANG II levels (48 ± 6 versus 106 ± 9 and 122 ± 19 versus 346 ± 11 fmol ml or g, respectively, P < 0.05) and increases in plasma and kidney angiotensin (1-7) concentrations (84 ± 9 versus 37 ± 6 and 199 ± 12 versus 68 ± 9 fmol/ml or g, respectively, P < 0.05). Remarkably, late EET-A treatment did not lower BP or improve renal and cardiac injury; indices of RAS activity were not affected. CONCLUSION: The new, orally active EET-A attenuated the development of experimental ANG II-dependent malignant hypertension, likely via suppression of the hypertensiogenic axis and augmentation of the vasodilatory/natriuretic axis of RAS.

• MeSH
• albuminurie farmakoterapie   MeSH
• angiotensin I metabolismus   MeSH
• angiotensin II metabolismus   MeSH
• časové faktory MeSH
• cytochrom P-450 CYP1A1 genetika   MeSH
• hypertenze maligní chemicky indukované   patofyziologie   prevence a kontrola   MeSH
• indoly MeSH
• krevní tlak účinky léků   MeSH
• krysa rodu Rattus MeSH
• kyselina 8,11,14-eikosatrienová analogy a deriváty   terapeutické užití   MeSH
• ledviny metabolismus   MeSH
• peptidové fragmenty metabolismus   MeSH
• potkani transgenní MeSH
• renin-angiotensin systém účinky léků   MeSH
• renin genetika   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• angiotensin I (1-7) MeSH Prohlížeč
• angiotensin I MeSH
• angiotensin II MeSH
• cytochrom P-450 CYP1A1 MeSH
• indole-3-carbinol MeSH Prohlížeč
• indoly MeSH
• kyselina 8,11,14-eikosatrienová MeSH
• peptidové fragmenty MeSH
• Ren2 protein, rat MeSH Prohlížeč
• renin MeSH

Recent studies have shown that the long-term antihypertensive action of soluble epoxide hydrolase inhibition (sEH) in angiotensin-II (AngII)-dependent hypertension might be mediated by the suppression of intrarenal AngII levels. To test this hypothesis, we examined the effects of acute (2 days) and chronic (14 days) sEH inhibition on blood pressure (BP) in transgenic rats with inducible AngII-dependent hypertension. AngII-dependent malignant hypertension was induced by 10 days' dietary administration of indole-3-carbinol (I3C), a natural xenobiotic that activates the mouse renin gene in Cyp1a1-Ren-2 transgenic rats. BP was monitored by radiotelemetry. Acute and chronic sEH inhibition was achieved using cis-4-(4-(3-adamantan-1-yl-ureido)cyclohexyloxy) benzoic acid, given at doses of 0.3, 3, 13, 26, 60 and 130 mg/L in drinking water. At the end of experiments, renal concentrations of epoxyeicosatrienoic acids, their inactive metabolites dihydroxyeicosatrienoic acids and AngII were measured. Acute BP-lowering effects of sEH inhibition in I3C-induced rats was associated with a marked increase in renal epoxyeicosatrienoic acids to dihydroxyeicosatrienoic acids ratio and acute natriuresis. Chronic treatment with cis-4-(4-(3-adamantan-1-yl-ureido)cyclohexyloxy) benzoic acid in I3C-induced rats elicited dose-dependent persistent BP lowering associated with a significant reduction of plasma and kidney AngII levels. Our findings show that the acute BP-lowering effect of sEH inhibition in I3C-induced Cyp1a1-Ren-2 transgenic rats is mediated by a substantial increase in intrarenal epoxyeicosatrienoic acids and their natriuretic action without altering intrarenal renin-angiotensin system activity. Long-term antihypertensive action of cis-4-(4-(3-adamantan-1-yl-ureido)cyclohexyloxy) benzoic acid in I3C-induced Cyp1a1-Ren-2 transgenic rats is mediated mostly by suppression of intrarenal AngII concentration.

• Klíčová slova
• angiotensin-II, cytochrome P-450 epoxygenase, eicosanoids, epoxyeicosatrienoic acids, hypertension, soluble epoxide hydrolase,
• MeSH
• angiotensin II metabolismus   MeSH
• antihypertenziva farmakologie   MeSH
• cytochrom P-450 CYP1A1 metabolismus   MeSH
• epoxid hydrolasy antagonisté a inhibitory   metabolismus   MeSH
• hypertenze farmakoterapie   metabolismus   MeSH
• indoly metabolismus   MeSH
• krevní tlak účinky léků   MeSH
• krysa rodu Rattus MeSH
• ledviny účinky léků   metabolismus   MeSH
• myši MeSH
• natriuréza účinky léků   MeSH
• potkani inbrední F344 MeSH
• potkani transgenní MeSH
• renin-angiotensin systém účinky léků   MeSH
• renin metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• angiotensin II MeSH
• antihypertenziva MeSH
• cytochrom P-450 CYP1A1 MeSH
• epoxid hydrolasy MeSH
• indole-3-carbinol MeSH Prohlížeč
• indoly MeSH
• Ren2 protein, rat MeSH Prohlížeč
• renin MeSH

1. The aim of the present study was to test the hypothesis that increasing kidney tissue concentrations of epoxyeicosatrienoic acids (EETs) by preventing their degradation to the biologically inactive dihydroxyeicosatrienoic acids (DHETEs) using blockade of soluble epoxide hydrolase (sEH) would attenuate the progression of chronic kidney disease (CKD). 2. Ren-2 transgenic rats (TGR) after 5/6 renal mass reduction (5/6 NX) served as a model of CKD associated with angiotensin (Ang) II-dependent hypertension. Soluble epoxide hydrolase was inhibited using cis-4-[4-(3-adamantan-1-yl-ureido)cyclohexyloxy]benzoic acid (c-AUCB; 3 mg/L drinking water) for 20 weeks after 5/6 NX. Sham-operated normotensive transgene-negative Hannover Sprague-Dawley (HanSD) rats served as controls. 3. When applied in TGR subjected to 5/6 NX, c-AUCB treatment improved survival rate, prevented the increase in blood pressure, retarded the progression of cardiac hypertrophy, reduced proteinuria and the degree of glomerular and tubulointerstitial injury and reduced glomerular volume. All these organ-protective actions were associated with normalization of the intrarenal EETs:DHETEs ratio, an index of the availability of biologically active EETs, to levels observed in sham-operated HanSD rats. There were no significant concurrent changes of increased intrarenal AngII content. 4. Together, these results show that 5/6 NX TGR exhibit a profound deficiency of intrarenal availability of active epoxygenase metabolites (EETs), which probably contributes to the progression of CKD in this model of AngII-dependent hypertension, and that restoration of intrarenal availability of EETs using long-term c-AUCB treatment exhibits substantial renoprotective actions.

• Klíčová slova
• 5/6 nephrectomy, chronic kidney disease, cytochrome P450 enzymes, end-organ damage, epoxyeicosatrienoic acids, hypertension, renin-angiotensin system, soluble epoxide hydrolase,
• MeSH
• angiotensin II farmakologie   MeSH
• chronická renální insuficience farmakoterapie   metabolismus   MeSH
• epoxid hydrolasy antagonisté a inhibitory   metabolismus   MeSH
• hypertenze farmakoterapie   metabolismus   MeSH
• krevní tlak účinky léků   MeSH
• krysa rodu Rattus MeSH
• míra přežití MeSH
• nefrektomie metody   MeSH
• potkani Sprague-Dawley MeSH
• potkani transgenní metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• angiotensin II MeSH
• epoxid hydrolasy MeSH