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.

• Keywords
• malignant hypertension, renin–angiotensin system, sodium-glucose cotransporter type 2 inhibitor, soluble guanylyl cyclase stimulator,
• MeSH
• Benzhydryl Compounds pharmacology   MeSH
• Sodium-Glucose Transporter 2 Inhibitors MeSH
• Glucosides pharmacology   therapeutic use   MeSH
• Hypertension, Malignant * prevention & control   drug therapy   MeSH
• Blood Pressure drug effects   MeSH
• Rats MeSH
• NG-Nitroarginine Methyl Ester pharmacology   MeSH
• Rats, Transgenic MeSH
• Pyrazoles * pharmacology   therapeutic use   MeSH
• Pyrimidines * therapeutic use   pharmacology   MeSH
• Soluble Guanylyl Cyclase * metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• BAY 41-8543 MeSH Browser
• Benzhydryl Compounds MeSH
• empagliflozin MeSH Browser
• Sodium-Glucose Transporter 2 Inhibitors MeSH
• Glucosides MeSH
• Morpholines MeSH
• NG-Nitroarginine Methyl Ester MeSH
• Pyrazoles * MeSH
• Pyrimidines * MeSH
• Soluble Guanylyl Cyclase * 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.

• Keywords
• Angiotensin II, Angiotensin-(1-7), Renin-angiotensin system, TG7371 transgenic rat,
• MeSH
• Angiotensin I * metabolism   MeSH
• Angiotensin II * MeSH
• Cardiovascular Diseases metabolism   genetics   MeSH
• Blood Pressure physiology   MeSH
• Rats MeSH
• Kidney metabolism   MeSH
• Kidney Diseases metabolism   genetics   MeSH
• Peptide Fragments * metabolism   MeSH
• Rats, Sprague-Dawley * MeSH
• Rats, Transgenic * MeSH
• Proto-Oncogene Mas MeSH
• Receptor, Angiotensin, Type 1 genetics   metabolism   MeSH
• Receptors, G-Protein-Coupled genetics   metabolism   MeSH
• Recombinant Fusion Proteins metabolism   MeSH
• Renin-Angiotensin System * physiology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• angiotensin I (1-7) MeSH Browser
• Angiotensin I * MeSH
• Angiotensin II * MeSH
• Peptide Fragments * MeSH
• Proto-Oncogene Mas MeSH
• Receptor, Angiotensin, Type 1 MeSH
• Receptors, G-Protein-Coupled MeSH
• Recombinant Fusion Proteins 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
• Denervation methods   MeSH
• Hypertension * physiopathology   complications   MeSH
• Cardio-Renal Syndrome * physiopathology   surgery   etiology   MeSH
• Rats MeSH
• Kidney * innervation   MeSH
• Disease Models, Animal MeSH
• Sympathectomy * methods   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Gliflozins (sodium-glucose transporter-2 inhibitors) exhibited renoprotective effects not only in diabetic but also in non-diabetic patients with chronic kidney disease (CKD). Controversial results were reported in experimental non-diabetic models of CKD. Therefore, we examined empagliflozin effects in three CKD models, namely, in fawn-hooded hypertensive (FHH) rats, uninephrectomized salt-loaded (UNX + HS) rats, and in rats with Goldblatt hypertension (two-kidney, one-clip 2K1C) that were either untreated or treated with empagliflozin (10 mg/kg/day) for eight weeks. Plethysmography blood pressure (BP) was recorded weekly, and renal parameters (proteinuria, plasma urea, creatinine clearance, and sodium excretion) were analyzed three times during the experiment. At the end of the study, blood pressure was also measured directly. Markers of oxidative stress (TBARS) and inflammation (MCP-1) were analyzed in kidney and plasma, respectively. Body weight and visceral adiposity were reduced by empagliflozin in FHH rats, without a significant effect on BP. Experimentally induced CKD (UNX + HS and 2K1C) was associated with a substantial increase in BP and relative heart and kidney weights. Empagliflozin influenced neither visceral adiposity nor BP in these two models. Although empagliflozin increased sodium excretion, suggesting effective SGLT-2 inhibition, it did not affect diuresis in any experimental model. Unexpectedly, empagliflozin did not provide renoprotection because proteinuria, plasma urea, and plasma creatinine were not lowered by empagliflozin treatment in all three CKD models. In line with these results, empagliflozin treatment did not decrease TBARS or MCP-1 levels in either model. In conclusion, empagliflozin did not provide the expected beneficial effects on kidney function in experimental models of CKD.

• Keywords
• SGLT-2 inhibition, fawn-hooded hypertensive rat, one-clip hypertension, proteinuria, two-kidney, uninephrectomized salt-loaded,
• Publication type
• Journal Article MeSH

It is generally accepted that angiotensin II plays an important role in high blood pressure (BP) development in both 2-kidney-1-clip (2K1C) Goldblatt hypertension and in partial nephrectomy (NX) model of chronic kidney disease (CKD). The contribution of sympathetic nervous system and nitric oxide to BP control in these models is less clear. Partial nephrectomy or stenosis of the renal artery was performed in adult (10-week-old) male hypertensive heterozygous Ren-2 transgenic rats (TGR) and normotensive control Hannover Sprague Dawley (HanSD) rats and in Wistar rats. One and four weeks after the surgery, basal blood pressure (BP) and acute BP responses to the consecutive blockade of renin-angiotensin (RAS), sympathetic nervous (SNS), and nitric oxide (NO) systems were determined in conscious rats. Both surgical procedures increased plasma urea, a marker of renal damage; the effect being more pronounced following partial nephrectomy in hypertensive TGR than in normotensive HanSD rats with a substantially smaller effect in Wistar rats after renal artery stenosis. We demonstrated that the renin-angiotensin system does not play so fundamental role in blood pressure maintenance during hypertension development in either CKD model. By contrast, a more important role is exerted by the sympathetic nervous system, the activity of which is increased in hypertensive TGR-NX in the developmental phase of hypertension, while in HanSD-NX or Wistar-2K1C it is postponed to the established phase. The contribution of the vasoconstrictor systems (RAS and SNS) was increased following hypertension induction. The role of NO-dependent vasodilation was unchanged in 5/6 NX HanSD and in 2K1C Wistar rats, while it gradually decreased in 5/6 NX TGR rats.

• MeSH
• Renal Insufficiency, Chronic complications   metabolism   physiopathology   MeSH
• Hypertension complications   metabolism   physiopathology   MeSH
• Blood Pressure physiology   MeSH
• Rats MeSH
• Disease Models, Animal MeSH
• Rats, Sprague-Dawley MeSH
• Rats, Transgenic MeSH
• Rats, Wistar MeSH
• Renin-Angiotensin System * MeSH
• Sympathetic Nervous System physiopathology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

INTRODUCTION: Previous studies in Ren-2 transgenic hypertensive rats (TGR) after 5/6 renal ablation (5/6 NX) have shown that besides pharmacological blockade of the renin-angiotensin system (RAS) also increasing kidney tissue epoxyeicosatrienoic acids (EET) levels by blocking soluble epoxide hydrolase (sEH), an enzyme responsible for degradation of EETs, and endothelin type A (ETA) receptor blockade retards chronic kidney disease (CKD) progression. This prompted us to evaluate if this progression will be alleviated by the addition of sEH inhibitor and ETA receptor antagonist to the standard complex blockade of RAS (angiotensin-converting enzyme inhibitor plus angiotensin II type 1 receptor blocker) in rats with established CKD. METHODS: The treatment regimens were initiated 6 weeks after 5/6 NX in TGR, and the follow-up period was 60 weeks. RESULTS: The addition of sEH inhibition to RAS blockade improved survival rate, further reduced albuminuria and renal glomerular and kidney tubulointerstitial injury, and attenuated the decline in creatinine clearance - all this as compared with 5/6 NX TGR treated with RAS blockade alone. Addition of ETA receptor antagonist to the combined RAS and sEH blockade not only offered no additional renoprotection but, surprisingly, also abolished the beneficial effects of adding sEH inhibitor to the RAS blockade. CONCLUSION: These data indicate that pharmacological strategies that combine the blockade of RAS and sEH could be a novel tool to combat the progression of CKD. Any attempts to further extend this therapeutic regimen should be made with extreme caution.

• Keywords
• 5/6 Renal mass reduction, Chronic kidney disease, Endothelin A receptor blocker, Hypertension, Renin-angiotensin system, Soluble epoxide hydrolase inhibitor,
• MeSH
• Endothelin A Receptor Antagonists pharmacology   MeSH
• Renal Insufficiency, Chronic prevention & control   MeSH
• Epoxide Hydrolases antagonists & inhibitors   MeSH
• Hypertension MeSH
• Rats MeSH
• Nephrectomy MeSH
• Rats, Transgenic MeSH
• Receptor, Endothelin A MeSH
• Renin-Angiotensin System drug effects   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Endothelin A Receptor Antagonists MeSH
• Epoxide Hydrolases MeSH
• Receptor, Endothelin A MeSH

We showed recently that increasing kidney epoxyeicosatrienoic acids (EETs) by blocking soluble epoxide hydrolase (sEH), an enzyme responsible for EETs degradation, retarded the development of renal dysfunction and progression of aorto-caval fistula(ACF)-induced congestive heart failure (CHF) in Ren-2 transgenic hypertensive rats (TGR). In that study the final survival rate of untreated ACF TGR was only 14 % but increased to 41 % after sEH blockade. Here we examined if sEH inhibition added to renin-angiotensin system (RAS) blockade would further enhance protection against ACF-induced CHF in TGR. The treatment regimens were started one week after ACF creation and the follow-up period was 50 weeks. RAS was blocked using angiotensin-converting enzyme inhibitor (ACEi, trandolapril, 6 mg/l) and sEH with an sEH inhibitor (sEHi, c-AUCB, 3 mg/l). Renal hemodynamics and excretory function were determined two weeks post-ACF, just before the onset of decompensated phase of CHF. 29 weeks post-ACF no untreated animal survived. ACEi treatment greatly improved the survival rate, to 84 % at the end of study. Surprisingly, combined treatment with ACEi and sEHi worsened the rate (53 %). Untreated ACF TGR exhibited marked impairment of renal function and the treatment with ACEi alone or combined with sEH inhibition did not prevent it. In conclusion, addition of sEHi to ACEi treatment does not provide better protection against CHF progression and does not increase the survival rate in ACF TGR: indeed, the rate decreases significantly. Thus, combined treatment with sEHi and ACEi is not a promising approach to further attenuate renal dysfunction and retard progression of CHF.

• MeSH
• Arteriovenous Fistula MeSH
• Benzoates pharmacology   therapeutic use   MeSH
• Epoxide Hydrolases antagonists & inhibitors   MeSH
• Indoles therapeutic use   MeSH
• Angiotensin-Converting Enzyme Inhibitors therapeutic use   MeSH
• Drug Therapy, Combination MeSH
• Rats MeSH
• Urea analogs & derivatives   pharmacology   therapeutic use   MeSH
• Rats, Sprague-Dawley MeSH
• Rats, Transgenic MeSH
• Drug Evaluation, Preclinical MeSH
• Renal Insufficiency etiology   prevention & control   MeSH
• Heart Failure complications   drug therapy   mortality   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• 4-(4-(3-adamantan-1-ylureido)cyclohexyloxy)benzoic acid MeSH Browser
• Benzoates MeSH
• Epoxide Hydrolases MeSH
• Indoles MeSH
• Angiotensin-Converting Enzyme Inhibitors MeSH
• Urea MeSH
• trandolapril MeSH Browser

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
• Albuminuria metabolism   MeSH
• Angiotensin II metabolism   MeSH
• Antihypertensive Agents pharmacology   MeSH
• Hypertension metabolism   MeSH
• Blood Pressure drug effects   MeSH
• Rats MeSH
• Arachidonic Acids pharmacology   MeSH
• Rats, Sprague-Dawley MeSH
• Rats, Transgenic MeSH
• Arrhythmias, Cardiac metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, N.I.H., Extramural MeSH
• Names of Substances
• Angiotensin II MeSH
• Antihypertensive Agents MeSH
• Arachidonic Acids 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.

• Keywords
• 5/6 nephrectomy, Chronic kidney disease, Epoxyeicosatrienoic acids, Hypertension, Renin-angiotensin system, Soluble epoxide hydrolase,
• MeSH
• Albuminuria drug therapy   MeSH
• Renal Insufficiency, Chronic drug therapy   mortality   physiopathology   surgery   MeSH
• Epoxide Hydrolases antagonists & inhibitors   MeSH
• Hypertension MeSH
• Angiotensin-Converting Enzyme Inhibitors therapeutic use   MeSH
• Drug Therapy, Combination MeSH
• Rats MeSH
• Survival Rate MeSH
• Nephrectomy MeSH
• Rats, Transgenic MeSH
• Renin-Angiotensin System drug effects   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Epoxide Hydrolases MeSH
• Angiotensin-Converting Enzyme Inhibitors MeSH

We elucidated the role of collecting duct kinin B2 receptor (B2R) in the development of salt-sensitivity and angiotensin II (ANG II)-induced hypertension. To this end, we used a Cre-Lox recombination strategy to generate mice lacking Bdkrb2 gene for B2R in the collecting duct (Hoxb7-Cre(tg/+):Bdkrb2(flox/flox)). In 3 groups of control (Bdkrb2(flox/flox)) and 3 groups of UB(Bdkrb2-/-) mice, systolic blood pressure (SBP) responses to high salt intake (4 or 8% NaCl; HS) were monitored by radiotelemetry in comparison with standard salt diet (0.4% NaCl) prior to and during subcutaneous ANG II infusion (1000 ng/min/kg) via osmotic minipumps. High salt intakes alone for 2 weeks did not alter SBP in either strain. ANG II significantly increased SBP equally in control (121 ± 2 to 156 ± 3 mmHg) and UB(Bdkrb2-/-) mice (120 ± 2 to 153 ± 2 mmHg). The development of ANG II-induced hypertension was exacerbated by 4%HS in both control (125 ± 3 to 164 ± 5 mmHg) and UB(Bdkrb2-/-) mice (124 ± 2 to 162 ± 3 mmHg) during 2 weeks. Interestingly, 8%HS caused a more profound and earlier ANG II-induced hypertension in UB(Bdkrb2-/-) (129 ± 2 to 166 ± 3 mmHg) as compared to control (128 ± 2 to 158 ± 2 mmHg) and it was accompanied by body weight loss and increased mortality. In conclusion, targeted inactivation of B2R in the renal collecting duct does not cause salt-sensitivity; however, collecting duct B2R attenuates the hypertensive actions of ANG II under conditions of very high salt intake.

• Keywords
• Angiotensin II, Cre recombinase, bradykinin receptor, collecting duct, high salt diet, hypertension, kallikrein–kinin system,
• MeSH
• Angiotensin II metabolism   MeSH
• Gene Knockout Techniques MeSH
• Hypertension * metabolism   physiopathology   MeSH
• Blood Pressure * drug effects   physiology   MeSH
• Sodium Chloride, Dietary adverse effects   MeSH
• Disease Models, Animal MeSH
• Mice MeSH
• Receptor, Bradykinin B2 genetics   MeSH
• Kidney Tubules, Collecting * metabolism   physiopathology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, N.I.H., Extramural MeSH
• Names of Substances
• Angiotensin II MeSH
• Sodium Chloride, Dietary MeSH
• Receptor, Bradykinin B2 MeSH