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

Detailed mechanism(s) of the beneficial effects of renal denervation (RDN) on the course of heart failure (HF) remain unclear. The study aimed to evaluate renal vascular responsiveness to angiotensin II (ANG II) and to characterize ANG II type 1 (AT1) and type 2 (AT2) receptors in the kidney of Ren-2 transgenic rats (TGR), a model of ANG II-dependent hypertension. HF was induced by volume overload using aorto-caval fistula (ACF). The studies were performed two weeks after RDN (three weeks after the creation of ACF), i.e., when non-denervated ACF TGR enter the decompensation phase of HF whereas those after RDN are still in the compensation phase. We found that ACF TGR showed lower renal blood flow (RBF) and its exaggerated response to intrarenal ANG II (8 ng); RDN further augmented this responsiveness. We found that all ANG II receptors in the kidney cortex were of the AT1 subtype. ANG II receptor binding characteristics in the renal cortex did not significantly differ between experimental groups, hence AT1 alterations are not responsible for renal vascular hyperresponsiveness to ANG II in ACF TGR, denervated or not. In conclusion, maintained renal AT1 receptor binding combined with elevated ANG II levels and renal vascular hyperresponsiveness to ANG II in ACF TGR influence renal hemodynamics and tubular reabsorption and lead to renal dysfunction in the high-output HF model. Since RDN did not attenuate the RBF decrease and enhanced renal vascular responsiveness to ANG II, the beneficial actions of RDN on HF-related mortality are probably not dominantly mediated by renal mechanism(s).

• Klíčová slova
• ANG II receptors, aorto-caval fistula, heart failure, renal denervation,
• Publikační typ
• časopisecké články MeSH

OBJECTIVE: We evaluated the hypothesis that the development of renal dysfunction and congestive heart failure (CHF) caused by volume overload in rats with angiotensin II (ANG II)-dependent hypertension is associated with altered renal vascular responsiveness to ANG II and to epoxyeicosatrienoic acids (EETs). METHODS: Ren-2 transgenic rats (TGRs) were used as a model of ANG II-dependent hypertension. CHF was induced by volume overload achieved by the creation of the aorto-caval fistula (ACF). Renal blood flow (RBF) responses were determined to renal arterial administration of ANG II, native 11,12-EET, an analog of 14,15-EETs (EET-A), norepinephrine (NE), acetylcholine (Ach) and bradykinin (Bk) in healthy (i.e., sham-operated) TGR and ACF TGR (5 weeks after ACF creation). RESULTS: Selective intrarenal administration of neither vasoactive drug altered mean arterial pressure in any group. Administration of ANG II caused greater decreases in RBF in ACF TGR than in sham-operated TGR, whereas after administration of NE the respective decreases were comparable in the 2 groups. Administration of Ach and Bk elicited significantly higher RBF increases in ACF TGR as compared with sham-operated TGR. In contrast, administration of 11,12-EET and EET-A caused significantly smaller RBF increases in ACF TGR than in sham-operated TGR. CONCLUSION: The findings show that 5 weeks after creation of ACF, the TGR exhibit exaggerated renal vasoconstrictor responses to ANG II and reduced renal vasodilatory responses to EETs, suggesting that both these alterations might play an important role in the development of renal dysfunction in this model of CHF.

• Klíčová slova
• Acetylcholine, Angiotensin II, Aorto-caval fistula, Bradykinin, Congestive heart failure, Epoxyeicosatrienoic acid, Hypertension, Norepinephrine, Renal blood flow, Renal dysfunction, Renal vascular reactivity,
• MeSH
• angiotensin II škodlivé účinky   MeSH
• arteria pulmonalis abnormality   patofyziologie   MeSH
• arterioarteriální píštěl patofyziologie   MeSH
• hypertenze chemicky indukované   komplikace   MeSH
• krysa rodu Rattus MeSH
• potkani transgenní MeSH
• renální oběh účinky léků   MeSH
• srdeční selhání komplikace   patofyziologie   MeSH
• vazodilatace účinky léků   MeSH
• vazokonstrikce účinky léků   MeSH
• vazokonstriktory farmakologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• angiotensin II MeSH
• vazokonstriktory MeSH

The aim of the present study was to evaluate the hypothesis that the antihypertensive effects of inhibition of soluble epoxide hydrolase (sEH) are mediated by increased intrarenal availability of epoxyeicosatrienoic acids (EETs), with consequent improvement in renal haemodynamic autoregulatory efficiency and the pressure-natriuresis relationship. Ren-2 transgenic rats (TGR), a model of angiotensin (Ang) II-dependent hypertension, and normotensive transgene-negative Hannover Sprague-Dawley (HanSD) rats were treated with the sEH inhibitor cis-4-(4-(3-adamantan-1-yl-ureido)cyclohexyloxy)benzoic acid (c-AUCB; 26 mg/L) for 48 h. Then, the effects on blood pressure (BP), autoregulation of renal blood flow (RBF) and glomerular filtration rate (GFR), and on the pressure-natriuresis relationship in response to stepwise reductions in renal arterial pressure (RAP) were determined. Treatment with c-AUCB did not significantly change BP, renal autoregulation or pressure-natriuresis in normotensive HanSD rats. In contrast, c-AUCB treatment significantly reduced BP, increased intrarenal bioavailability of EETs and significantly suppressed AngII levels in TGR. However, treatment with c-AUCB did not significantly improve the autoregulatory efficiency of RBF and GFR in response to reductions of RAP and to restore the blunted pressure-natriuresis relationship in TGR. Together, the data indicate that the antihypertensive actions of sEH inhibition in TGR are predominantly mediated via significant suppression of intrarenal renin-angiotensin system activity.

• MeSH
• antihypertenziva farmakologie   MeSH
• benzoáty farmakologie   MeSH
• down regulace účinky léků   MeSH
• epoxid hydrolasy antagonisté a inhibitory   MeSH
• hodnoty glomerulární filtrace účinky léků   MeSH
• hypertenze patofyziologie   MeSH
• krevní tlak účinky léků   MeSH
• krysa rodu Rattus MeSH
• ledviny účinky léků   metabolismus   MeSH
• močovina analogy a deriváty   farmakologie   MeSH
• potkani Sprague-Dawley MeSH
• potkani transgenní MeSH
• renální oběh účinky léků   MeSH
• renin-angiotensin systém účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• 4-(4-(3-adamantan-1-ylureido)cyclohexyloxy)benzoic acid MeSH Prohlížeč
• antihypertenziva MeSH
• benzoáty MeSH
• epoxid hydrolasy MeSH
• močovina MeSH

In the present study, we examined the effects of soluble epoxide hydrolase (sEH) inhibition on the development of angiotensin II-dependent hypertension and on renal function in transgenic rats with inducible expression of the mouse renin gene (strain name Cyp1a1-Ren-2). Hypertension was induced in these rats by indole-3-carbinol (I3C; 0.3% in the diet) for 12 days. The sEH inhibitor cis-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (c-AUCB) was given in two doses (13 or 26 mg l-1) in drinking water. Blood pressure (BP), body weight (BW) and renal excretory parameters were monitored in conscious animals during the experiment. Renal haemodynamics was assessed at the end of treatment in anaesthetized rats. I3C administration resulted in severe hypertension with a rise in systolic BP from 118 ± 2 to 202 ± 3 mmHg, a loss of BW from 266 ± 5 to 228 ± 4 g and a rise in proteinuria from 14 ± 2 to 34 ± 3 mg day-1. Both doses of c-AUCB significantly attenuated the development of hypertension (systolic BP of 181 ± 4 and 176 ± 4 mmHg, respectively), the loss in BW (256 ± 4 and 259 ± 3 g, respectively) and the degree of proteinuria (27 ± 2 and 25 ± 3 mg day-1, respectively) to a similar extent. Moreover, c-AUCB prevented the reduction in renal plasma flow (5.4 ± 0.4 vs. 4.6 ± 0.3 ml min-1 g-1) and significantly increased sodium excretion (0.84 ± 0.16 vs. 0.38 ± 0.08 μmol min-1 g-1) during I3C administration. These data suggest that the oral administration of c-AUCB displays antihypertensive effects in Ren-2 transgenic rats with inducible malignant hypertension via an improvement of renal function.

• MeSH
• angiotensin II MeSH
• antihypertenziva aplikace a dávkování   farmakologie   MeSH
• aplikace orální MeSH
• benzoáty aplikace a dávkování   farmakologie   MeSH
• časové faktory MeSH
• cytochrom P-450 CYP1A1 genetika   MeSH
• epoxid hydrolasy antagonisté a inhibitory   metabolismus   MeSH
• hodnoty glomerulární filtrace účinky léků   MeSH
• hypertenze chemicky indukované   enzymologie   genetika   patofyziologie   prevence a kontrola   MeSH
• inhibitory enzymů aplikace a dávkování   farmakologie   MeSH
• krevní tlak účinky léků   MeSH
• krysa rodu Rattus MeSH
• kyseliny arachidonové metabolismus   MeSH
• kyseliny hydroxyeikosatetraenové metabolismus   MeSH
• ledviny krevní zásobení   účinky léků   enzymologie   patofyziologie   MeSH
• močovina aplikace a dávkování   analogy a deriváty   farmakologie   MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• promotorové oblasti (genetika) MeSH
• proteinurie metabolismus   patofyziologie   prevence a kontrola   MeSH
• renální průtok plazmy účinky léků   MeSH
• renin genetika   metabolismus   MeSH
• sodík moč   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
• 4-(4-(3-adamantan-1-ylureido)cyclohexyloxy)benzoic acid MeSH Prohlížeč
• angiotensin II MeSH
• antihypertenziva MeSH
• benzoáty MeSH
• cytochrom P-450 CYP1A1 MeSH
• EPHX2 protein, rat MeSH Prohlížeč
• epoxid hydrolasy MeSH
• inhibitory enzymů MeSH
• kyseliny arachidonové MeSH
• kyseliny hydroxyeikosatetraenové MeSH
• močovina MeSH
• Ren2 protein, mouse MeSH Prohlížeč
• renin MeSH
• sodík MeSH

Recent studies have shown that the renal CYP450 (cytochrome P450) metabolites of AA (arachidonic acid), the vasoconstrictor 20-HETE (20-hydroxyeicosatetraenoic acid) and the vasodilator EETs (epoxyeicosatrienoic acids), play an important role in the pathophysiology of AngII (angiotensin II)-dependent forms of hypertension and the associated target organ damage. The present studies were performed in Ren-2 renin transgenic rats (TGR) to evaluate the effects of chronic selective inhibition of 20-HETE formation or elevation of the level of EETs, alone or in combination, on the course of hypertension and hypertension-associated end-organ damage. Both young (30 days of age) prehypertensive TGR and adult (190 days of age) TGR with established hypertension were examined. Normotensive HanSD (Hannover Sprague-Dawley) rats served as controls. The rats were treated with N-methylsulfonyl-12,12-dibromododec-11-enamide to inhibit 20-HETE formation and/or with N-cyclohexyl-N-dodecyl urea to inhibit soluble epoxide hydrolase and prevent degradation of EETs. Inhibition in TGR of 20-HETE formation combined with enhanced bioavailability of EETs attenuated the development of hypertension, cardiac hypertrophy, proteinuria, glomerular hypertrophy and sclerosis as well as renal tubulointerstitial injury. This was also associated with attenuation of the responsiveness of the systemic and renal vascular beds to AngII without modifying their responses to noradrenaline (norepinephrine). Our findings suggest that altered production and/or action of 20-HETE and EETs plays a permissive role in the development of hypertension and hypertension-associated end-organ damage in this model of AngII-dependent hypertension. This information provides a basis for a search for new therapeutic approaches for the treatment of hypertension.

• MeSH
• amidy farmakologie   terapeutické užití   MeSH
• angiotensin II farmakologie   MeSH
• antihypertenziva farmakologie   terapeutické užití   MeSH
• hypertenze komplikace   farmakoterapie   patofyziologie   MeSH
• krevní tlak účinky léků   MeSH
• krysa rodu Rattus MeSH
• kyselina 8,11,14-eikosatrienová analogy a deriváty   metabolismus   MeSH
• kyseliny hydroxyeikosatetraenové biosyntéza   MeSH
• multiorgánové selhání etiologie   prevence a kontrola   MeSH
• noradrenalin farmakologie   MeSH
• potkani Sprague-Dawley MeSH
• potkani transgenní MeSH
• preklinické hodnocení léčiv metody   MeSH
• renální oběh účinky léků   MeSH
• sulfony farmakologie   terapeutické užití   MeSH
• vazokonstriktory farmakologie   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
• Názvy látek
• 11,12-epoxy-5,8,14-eicosatrienoic acid MeSH Prohlížeč
• 20-hydroxy-5,8,11,14-eicosatetraenoic acid MeSH Prohlížeč
• amidy MeSH
• angiotensin II MeSH
• antihypertenziva MeSH
• DDMS MeSH Prohlížeč
• kyselina 8,11,14-eikosatrienová MeSH
• kyseliny hydroxyeikosatetraenové MeSH
• noradrenalin MeSH
• sulfony MeSH
• vazokonstriktory MeSH

OBJECTIVE: The present study was performed to examine in two-kidney, one-clip (2K1C) Goldblatt hypertensive mice: first, the relative contribution of angiotensin II receptor subtypes 1A (AT(1A)) and 1B (AT(1B)); second, the role of angiotensin II type 2 (AT(2)) receptors in the development of hypertension in wild-type (AT(1A)+/+) and AT(1A) receptor knockout (AT(1A)-/-) mice; and third, the role of increased nitric oxide synthase activity in counteracting the hypertensinogenic action of angiotensin II in this model. METHODS: AT(1A)+/+ and AT(1A)-/- mice underwent clipping of one renal artery and were infused with either saline vehicle or selective AT(2) receptor agonist CGP-42112A (CGP). Blood pressure was monitored by radiotelemetry. Blood pressure responses to the nitric oxide synthase inhibitor nitro-L-arginine-methyl-ester were evaluated. RESULTS: AT(1A)+/+ mice responded to clipping by a rise in blood pressure that was not modified by CGP infusion. Clip placement caused a slight increase in blood pressure in AT(1A)-/- mice that remained significantly lower than in AT(1A)+/+ mice. Acute nitric oxide synthase inhibition caused greater increase in blood pressure in 2K1C/AT(1A)+/+ than in AT(1A)+/+ mice. CONCLUSION: The present data support the critical role of AT(1A) receptors in the development of 2K1C hypertension, whereas AT(1B) receptors play only a minor role in blood pressure regulation in this model of angiotensin II-dependent hypertension. Activation of AT(2) receptors does not play an antagonistic role in the AT(1) receptor-mediated hypertensinogenic actions of angiotensin II in this model. Finally, enhanced nitric oxide synthase activity plays a protective role by counteracting the vasoconstrictor influences of angiotensin II in 2K1C hypertensive mice.

• MeSH
• arteria renalis MeSH
• hypertenze genetika   patofyziologie   MeSH
• ligace MeSH
• modely nemocí na zvířatech MeSH
• myši knockoutované MeSH
• myši MeSH
• receptor angiotensinu typ 1 genetika   fyziologie   MeSH
• receptor angiotensinu typ 2 genetika   fyziologie   MeSH
• renin-angiotensin systém fyziologie   MeSH
• synthasa oxidu dusnatého fyziologie   MeSH
• zvířata MeSH
• Check Tag
• 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
• receptor angiotensinu typ 1 MeSH
• receptor angiotensinu typ 2 MeSH
• synthasa oxidu dusnatého MeSH