OBJECTIVE: Despite availability of an array of antihypertensive drugs, malignant hypertension remains a life-threatening condition, and new therapeutic strategies for the treatment of malignant hypertension and malignant hypertension-associated organ damage are needed. The aim of the present study was to assess the effects of nitric oxide (NO)-independent soluble guanylyl cyclase (sGC) stimulator on the course of malignant hypertension. The second aim was to investigate if the treatment with sodium-glucose cotransporter type 2 (SGLT2) inhibitor would augment the expected beneficial actions of the sGC stimulation on the course of malignant hypertension. METHODS: As a model of malignant hypertension, Ren-2 transgenic rats (TGR) treated with nonspecific NO synthase inhibitor (Nω-nitro- l -arginine methyl ester, l -NAME) was used. Blood pressure (BP) was monitored by radiotelemetry, and the treatment was started 3 days before administration of l -NAME. RESULTS: The treatment with sGC stimulator BAY 41-8543, alone or combined with SGLT2 inhibitor empagliflozin, abolished malignant hypertension-related mortality in TGR receiving l -NAME. These two treatment regimens also prevented BP increases after l -NAME administration in TGR, and even decreased BP below values observed in control TGR, and prevented cardiac dysfunction and malignant hypertension-related morbidity. The treatment with the SGLT2 inhibitor empagliflozin did not further augment the beneficial actions of sGC stimulator on the course of malignant hypertension-related mortality. CONCLUSION: The treatment with NO-independent sGC stimulator displayed marked protective actions on the course of malignant hypertension-related mortality and malignant hypertension-related cardiac damage. This suggests that application of sGC stimulator could be a promising therapeutic means for the treatment of malignant hypertension.

• Klíčová slova
• malignant hypertension, renin–angiotensin system, sodium-glucose cotransporter type 2 inhibitor, soluble guanylyl cyclase stimulator,
• MeSH
• benzhydrylové sloučeniny farmakologie   MeSH
• glifloziny MeSH
• glukosidy farmakologie   terapeutické užití   MeSH
• hypertenze maligní * prevence a kontrola   farmakoterapie   MeSH
• krevní tlak účinky léků   MeSH
• krysa rodu Rattus MeSH
• morfoliny MeSH
• NG-nitroargininmethylester farmakologie   MeSH
• potkani transgenní MeSH
• pyrazoly * farmakologie   terapeutické užití   MeSH
• pyrimidiny * terapeutické užití   farmakologie   MeSH
• rozpustná guanylátcyklasa * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• BAY 41-8543 MeSH Prohlížeč
• benzhydrylové sloučeniny MeSH
• empagliflozin MeSH Prohlížeč
• glifloziny MeSH
• glukosidy MeSH
• morfoliny MeSH
• NG-nitroargininmethylester MeSH
• pyrazoly * MeSH
• pyrimidiny * MeSH
• rozpustná guanylátcyklasa * MeSH

The aim of the present study was to assess systemic circulatory and tissue activities of both the classical arm and of the alternative arm of the renin-angiotensin system (RAS) in a new transgenic rat line (TG7371) that expresses angiotensin-(1-7) (ANG 1-7)-producing fusion protein; the results were compared with the activities measured in control transgene-negative Hannover Sprague-Dawley (HanSD) rats. Plasma and tissue concentrations of angiotensin II (ANG II) and ANG 1-7, and kidney mRNA expressions of receptors responsible for biological actions of ANG II and ANG 1-7 [i.e. ANG II type 1 and type 2 (AT1 and AT2) and Mas receptors] were assessed in TG7371 transgene-positive and in HanSD rats. We found that male TG7371 transgene-positive rats exhibited significantly elevated plasma, kidney, heart and lung ANG 1-7 concentrations as compared with control male HanSD rats; by contrast, there was no significant difference in ANG II concentrations and no significant differences in mRNA expression of AT1, AT2 and Mas receptors. In addition, we found that in male TG7371 transgene-positive rats blood pressure was lower than in male HanSD rats. These data indicate that the balance between the classical arm and the alternative arm of the RAS was in male TGR7371 transgene-positive rats markedly shifted in favor of the latter. In conclusion, TG7371 transgene-positive rats represent a new powerful tool to study the long-term role of the alternative arm of the RAS in the pathophysiology and potentially in the treatment of cardio-renal diseases.

• Klíčová slova
• Angiotensin II, Angiotensin-(1-7), Renin-angiotensin system, TG7371 transgenic rat,
• MeSH
• angiotensin I * metabolismus   MeSH
• angiotensin II * MeSH
• kardiovaskulární nemoci metabolismus   genetika   MeSH
• krevní tlak fyziologie   MeSH
• krysa rodu Rattus MeSH
• ledviny metabolismus   MeSH
• nemoci ledvin metabolismus   genetika   MeSH
• peptidové fragmenty * metabolismus   MeSH
• potkani Sprague-Dawley * MeSH
• potkani transgenní * MeSH
• protoonkogen Mas MeSH
• receptor angiotensinu typ 1 genetika   metabolismus   MeSH
• receptory spřažené s G-proteiny genetika   metabolismus   MeSH
• rekombinantní fúzní proteiny metabolismus   MeSH
• renin-angiotensin systém * fyziologie   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
• peptidové fragmenty * MeSH
• protoonkogen Mas MeSH
• receptor angiotensinu typ 1 MeSH
• receptory spřažené s G-proteiny MeSH
• rekombinantní fúzní proteiny MeSH

Combination of chronic kidney disease (CKD) and heart failure (HF) results in extremely high morbidity and mortality. The current guideline-directed medical therapy is rarely effective and new therapeutic approaches are urgently needed. The study was designed to examine if renal denervation (RDN) will exhibit long-standing beneficial effects on the HF- and CKD-related morbidity and mortality. Fawn-hooded hypertensive rats (FHH) served as a genetic model of CKD and fawn-hooded low-pressure rats (FHL) without CKD served as controls. HF was induced by creation of aorto-caval fistula (ACF). RDN was performed 28 days after creation of ACF and the follow-up period was 70 days. ACF FHH subjected to sham-RDN had survival rate of 34 % i.e. significantly lower than 79 % observed in sham-denervated ACF FHL. RDN did not improve the condition and the final survival rate, both in ACF FHL and in ACF FHH. In FHH basal albuminuria was markedly higher than in FHL, and further increased throughout the study. RDN did not lower albuminuria and did not reduce renal glomerular damage in FHH. In these rats creation of ACF resulted in marked bilateral cardiac hypertrophy and alterations of cardiac connexin-43, however, RDN did not modify any of the cardiac parameters. Our present results further support the notion that kidney damage aggravates the HF-related morbidity and mortality. Moreover, it is clear that in the ACF FHH model of combined CKD and HF, RDN does not exhibit any important renoprotective or cardioprotective effects and does not reduce mortality. Key words Chronic kidney disease, Heart failure, Renal denervation, Fawn-hooded hypertensive rats.

• MeSH
• denervace metody   MeSH
• hypertenze * patofyziologie   komplikace   MeSH
• kardiorenální syndrom * patofyziologie   chirurgie   etiologie   MeSH
• krysa rodu Rattus MeSH
• ledviny * inervace   MeSH
• modely nemocí na zvířatech MeSH
• sympatektomie * metody   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

All anthracyclines, including doxorubicin (DOXO), the most common and still indispensable drug, exhibit cardiotoxicity with inherent risk of irreversible cardiomyopathy leading to heart failure with reduced ejection fraction (HFrEF). Current pharmacological strategies are clearly less effective for this type of HFrEF, hence an urgent need for new therapeutic approaches. The prerequisite for success is thorough understanding of pathophysiology of this HFrEF form, which requires an appropriate animal model of the disease. The aim of this study was to comprehensively characterise a novel model of HF with cardiorenal syndrome, i.e. DOXO-induced HFrEF with nephrotic syndrome, in which DOXO was administered to Ren-2 transgenic rats (TGR) via five intravenous injections in a cumulative dose of 10 mg/kg of body weight (BW). Our analysis included survival, echocardiography, as well as histological examination of the heart and kidneys, blood pressure, but also a broad spectrum of biomarkers to evaluate cardiac remodelling, fibrosis, apoptosis, oxidative stress and more. We have shown that the new model adequately mimics the cardiac remodelling described as "eccentric chamber atrophy" and myocardial damage typical for DOXO-related cardiotoxicity, without major damage of the peritoneum, lungs and liver. This pattern corresponds well to a clinical situation of cancer patients receiving anthracyclines, where HF develops with some delay after the anticancer therapy. Therefore, this study may serve as a comprehensive reference for all types of research on DOXO-related cardiotoxicity, proving especially useful in the search for new therapeutic strategies.

• Klíčová slova
• Chemotherapy induced heart failure, Doxorubicin, Experimental model of heart failure, NO/sGC/cGMP pathway, Ren-2 transgenic hypertensive rat,
• MeSH
• doxorubicin * škodlivé účinky   MeSH
• krysa rodu Rattus MeSH
• ledviny účinky léků   patofyziologie   MeSH
• modely nemocí na zvířatech * MeSH
• nefrotický syndrom * chemicky indukované   farmakoterapie   patofyziologie   MeSH
• oxidační stres účinky léků   MeSH
• potkani transgenní * MeSH
• protinádorová antibiotika škodlivé účinky   MeSH
• srdeční selhání * chemicky indukované   patofyziologie   MeSH
• tepový objem * účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• doxorubicin * MeSH
• protinádorová antibiotika MeSH

The study of ontogenetic aspects of water and electrolyte metabolism performed in the Institute of Physiology (Czechoslovak Academy of Sciences) led to the research on the increased susceptibility of immature rats to salt-dependent forms of hypertension since 1966. Hemodynamic studies in developing rats paved the way to the evaluation of hemodynamic mechanisms during the development of genetic hypertension in SHR. A particular attention was focused on altered renal function and kidney damage in both salt and genetic hypertension with a special respect to renin-angiotensin system. Renal damage associated with hypertension progression was in the center of interest of several research groups in Prague. The alterations in ion transport, cell calcium handling and membrane structure as well as their relationship to abnormal lipid metabolism were studied in a close cooperation with laboratories in Munich, Glasgow, Montreal and Paris. The role of NO and oxidative stress in various forms of hypertension was a subject of a joint research with our Slovak colleagues focused mainly on NO-deficient hypertension elicited by chronic L-NAME administration. Finally, we adopted a method enabling us to evaluate the balance of vasoconstrictor and vasodilator mechanisms in BP maintenance. Using this method we demonstrated sympathetic hyperactivity and relative NO deficiency in rats with either salt-dependent or genetic hypertension. At the end of the first decennium of this century we were ready to modify our traditional approach towards modern trends in the research of experimental hypertension. Keywords: Salt-dependent hypertension o Genetic hypertension o Body fluids o Hemodynamics o Ion transport o Cell membrane structure and function o Renal function o Renin-angiotensin systems.

• MeSH
• dějiny 20. století MeSH
• dějiny 21. století MeSH
• hypertenze * metabolismus   patofyziologie   MeSH
• krevní tlak MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• renin-angiotensin systém MeSH
• zvířata MeSH
• Check Tag
• dějiny 20. století MeSH
• dějiny 21. století MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• historické 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

OBJECTIVE: Evaluation of the effect of endothelin type A (ET A ) receptor blockade on the course of volume-overload heart failure in rats with angiotensin II-dependent hypertension. METHODS: Ren-2 renin transgenic rats (TGR) were used as a model of hypertension. Heart failure was induced by creating an aorto-caval fistula (ACF). Selective ET A receptor blockade was achieved by atrasentan. For comparison, other rat groups received trandolapril, an angiotensin-converting enzyme inhibitor (ACEi). Animals first underwent ACF creation and 2 weeks later the treatment with atrasentan or trandolapril, alone or combined, was applied; the follow-up period was 20 weeks. RESULTS: Eighteen days after creating ACF, untreated TGR began to die, and none was alive by day 79. Both atrasentan and trandolapril treatment improved the survival rate, ultimately to 56% (18 of 31 animals) and 69% (22 of 32 animals), respectively. Combined ACEi and ET A receptor blockade improved the final survival rate to 52% (17 of 33 animals). The effects of the three treatment regimens on the survival rate did not significantly differ. All three treatment regimens suppressed the development of cardiac hypertrophy and lung congestion, decreased left ventricle (LV) end-diastolic volume and LV end-diastolic pressure, and improved LV systolic contractility in ACF TGR as compared with their untreated counterparts. CONCLUSION: The treatment with ET A receptor antagonist delays the onset of decompensation of volume-overload heart failure and improves the survival rate in hypertensive TGR with ACF-induced heart failure. However, the addition of ET A receptor blockade did not enhance the beneficial effects beyond those obtained with standard treatment with ACEi alone.

• MeSH
• angiotensin II MeSH
• atrasentan MeSH
• endotelin-1 MeSH
• endoteliny MeSH
• hypertenze * komplikace   farmakoterapie   MeSH
• inhibitory ACE farmakologie   MeSH
• krysa rodu Rattus MeSH
• píštěle * MeSH
• potkani transgenní MeSH
• receptor angiotensinu typ 1 MeSH
• receptor endotelinu A MeSH
• srdeční selhání * farmakoterapie   etiologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• angiotensin II MeSH
• atrasentan MeSH
• endotelin-1 MeSH
• endoteliny MeSH
• inhibitory ACE MeSH
• receptor angiotensinu typ 1 MeSH
• receptor endotelinu A 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

This study evaluates the effects of chronic treatment with EET-A, an orally active epoxyeicosatrienoic acid (EETs) analog, on the course of aorto-caval fistula (ACF)-induced heart failure (HF) in Ren-2 transgenic rats (TGR), a model characterized by hypertension and augmented activity of the renin-angiotensin system (RAS). The results were compared with standard pharmacological blockade of the RAS using angiotensin-converting enzyme inhibitor (ACEi). The rationale for employing EET-A as a new treatment approach is based on our findings that apart from increased RAS activity, untreated ACF TGR also shows kidney and left ventricle (LV) tissue deficiency of EETs. Untreated ACF TGR began to die 17 days after creating ACF and were all dead by day 84. The treatment with EET-A alone or ACEi alone improved the survival rate: in 156 days after ACF creation, it was 45.5% and 59.4%, respectively. The combined treatment with EET-A and ACEi appeared to improve the final survival to 71%; however, the difference from either single treatment regimen did not reach significance. Nevertheless, our findings support the notion that targeting the cytochrome P-450-dependent epoxygenase pathway of arachidonic acid metabolism should be considered for the treatment of HF.

• Klíčová slova
• Ren-2 transgenic rats, angiotensin-converting enzyme inhibitor, aorto-caval fistula, congestive heart failure, cytochrome P-450, epoxyeicosatrienoic acids, hypertension, renin-angiotensin system, volume-overload heart failure,
• Publikační typ
• časopisecké články MeSH

The aim of the present study was to perform kidney messenger ribonucleic acid (mRNA) analysis in normotensive, Hannover Sprague-Dawley (HanSD) rats and hypertensive, Ren-2 renin transgenic rats (TGR) after doxorubicin-induced heart failure (HF) with specific focus on genes that are implicated in the pathophysiology of HF-associated cardiorenal syndrome. We found that in both strains renin and angiotensin-converting enzyme mRNA expressions were upregulated indicating that the vasoconstrictor axis of the renin-angiotensin system was activated. We found that pre-proendothelin-1, endothelin-converting enzyme type 1 and endothelin type A receptor mRNA expressions were upregulated in HanSD rats, but not in TGR, suggesting the activation of endothelin system in HanSD rats, but not in TGR. We found that mRNA expression of cytochrome P-450 subfamily 2C23 was downregulated in TGR and not in HanSD rats, suggesting the deficiency in the intrarenal cytochrome P450-dependent pathway of arachidonic acid metabolism in TGR. These results should be the basis for future studies evaluating the pathophysiology of cardiorenal syndrome secondary to chemotherapy-induced HF in order to potentially develop new therapeutic approaches.

• Klíčová slova
• chemotherapy-induced heart failure, cytochrome P-450, doxorubicin, endothelin system, hypertension, kidney, renal adrenergic system, renin-angiotensin-aldosterone system,
• MeSH
• doxorubicin škodlivé účinky   MeSH
• hypertenze komplikace   genetika   patofyziologie   MeSH
• krysa rodu Rattus MeSH
• ledviny účinky léků   patofyziologie   MeSH
• messenger RNA genetika   MeSH
• nemoci ledvin chemicky indukované   genetika   patofyziologie   MeSH
• potkani Sprague-Dawley MeSH
• potkani transgenní MeSH
• protinádorová antibiotika škodlivé účinky   MeSH
• regulace genové exprese účinky léků   MeSH
• renin-angiotensin systém účinky léků   MeSH
• renin genetika   MeSH
• srdeční selhání chemicky indukované   genetika   patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• doxorubicin MeSH
• messenger RNA MeSH
• protinádorová antibiotika MeSH
• Ren2 protein, rat MeSH Prohlížeč
• renin MeSH