Aims: The present study was performed to evaluate the effects of target disruption of the G-protein-coupled receptor Mas for angiotensin 1–7 [Ang(1–7)] in knockout mice on the course of two-kidney, one-clip (2K1C) Goldblatt hypertension. Methods: Knockout and wild-type mice underwent clipping of one renal artery. Blood pressure (BP) was monitored by radiotelemetry. The mice were either untreated or chronically treated with the superoxide (O₂^–) scavenger tempol (400 mg/l) or the inhibitor of NADPH oxidase apocynin (1 g/l) administered in drinking water. Results: Knockout mice responded to clipping by accelerated increases in BP and the final BP was significantly higher than that in wild-type mice. Chronic treatment with tempol or apocynin elicited similar antihypertensive effects in 2K1C/knockout as in 2K1C/wild-type mice. Acute nitric oxide synthase inhibition caused greater BP increases in 2K1C/wild-type than in 2K1C/knockout mice. Conclusion: Our present findings support the notion that the angiotensin-converting enzyme 2-Ang(1–7)-Mas axis serves as an important endogenous physiological counterbalancing mechanism that partially attenuates the hypertensinogenic actions of the activated renin-angiotensin system. The impairment in this axis may contribute to the deterioration of the course of 2K1C Goldblatt hypertension.

The effects of the human renin inhibitor aliskiren on blood pressure (BP), end-organ damage, proteinuria, and tissue and plasma angiotensin (ANG) II levels in young and adult heterozygous Ren-2 transgenic rats (TGR) were evaluated and compared with the effect of the ANG type 1 (AT1) receptor blocker losartan during treatment and after 12 days after the withdrawal of drug treatments. BP was monitored by telemetry from the age of 32 days on (young rats) and at 100 days (adult rats). Aliskiren (10 mg · kg Ϫ1 · day Ϫ1 in osmotic minipumps) or losartan (5 mg · kg Ϫ1 · day Ϫ1 in drinking water) treatment was applied for 28 days in young rats and for 70 days in adult rats. In young untreated TGR, severe hypertension rapidly evolved. Adult untreated TGR exhibited stable established hypertension. Both aliskiren and losartan fully prevented the development of hypertension and cardiac hypertrophy in young TGR and normalized BP and cardiac hypertrophy in adult TGR. After cessation of aliskiren treatment in both young and adult TGR BP and cardiac hypertrophy were persistently reduced, while after losartan withdrawal BP and cardiac hypertrophy rapidly increased. In adult aliskiren-treated rats proteinuria was significantly reduced compared with losartan (the effect persisting after withdrawal of treatment), and this decrease strongly correlated with normalization of glomerular size in these animals. In conclusion, aliskiren and losartan had similar antihypertensive effects during chronic treatment, but the antihypertensive and organoprotective effects of aliskiren were persistent even after the 12-day washout period. The durable effect on proteinuria can possibly be attributed to the normalization of glomerular morphology. losartan; hypertension; direct renin inhibition; glomerular size; morphometry; washout period; blood pressure ALISKIREN, the first clinically approved direct renin inhibitor (31), is a human-specific renin inhibitor that has been demonstrated as an effective blood pressure (BP)-lowering compound in animal and human studies (4, 19, 26) with substantial antiproteinuric (14, 26, 28) and cardioprotective (30, 36) activity. Aliskiren is generally well tolerated, and in combination with other antihypertensives, especially in diabetic patients, it has beneficial effects on proteinuria (10, 26). Recently, much attention has been devoted to the role of (pro)renin receptor in prevention of end-organ damage (9, 12) in both experimental and clinical studies.Models that harbor an extra human [double transgenic rats (2)] or murine [Ren-2 transgenic rats (22)] renin are suitable models for studying the effect of a human renin inhibitor since aliskiren has preferential affinity for human and mouse renin, while that for rat renin is very low. Ren-2 transgenic rats [TGR; official strain name TGR(mRen2-27)] represent a wellestablished model of ANG II-dependent malignant hypertension.Aliskiren has been shown to have antihypertensive and cardioprotective effects in Ren-2 TGR (37) and, additionally, to have nephroprotective (14)...

Local application of ADSCs resulted in significantly higher fistula closure rate on an animal model. BLI monitoring was proved to be feasible and showed rapid reduction of the ADSC mass after application. More viable cells were detected in animals with healed fistula at the end of the follow-up.

The present experiments were performed to evaluate if increased heart tissue concentration of fatty acids, specifically myristic, palmitic and palmitoleic acids that are believed to promote physiological heart growth, can attenuate the progression of unloading-induced cardiac atrophy in rats with healthy and failing hearts. Heterotopic abdominal heart transplantation (HTx) was used as a model for heart unloading. Cardiac atrophy was assessed from the ratio of the native- to-transplanted heart weight (HW). The degree of cardiac atrophy after HTx was determined on days 7, 14, 21 and 28 after HTx in recipients of either healthy or failing hearts. HTx of healthy hearts resulted in 23±3, 46±3, 48±4 and 46±4 % HW loss at the four time-points. HTx of the failing heart resulted in even greater HW losses, of 46±4, 58±3, 66±2 and 68±4 %, respectively (P<0.05). Activation of “fetal gene cardiac program” (e.g. beta myosin heavy chain gene expression) and “genes reflecting cardiac remodeling” (e.g. atrial natriuretic peptide gene expression) after HTx was greater in failing than in healthy hearts (P<0.05 each time). Exposure to isocaloric high sugar diet caused significant increases in fatty acid concentrations in healthy and in failing hearts. However, these increases were not associated with any change in the course of cardiac atrophy, similarly in healthy and post-HTx failing hearts. We conclude that increasing heart tissue concentrations of the fatty acids allegedly involved in heart growth does not attenuate the unloading-induced cardiac atrophy.

Acute liver failure (ALF) is a clinical condition with very high mortality rate. Its pathophysiological background is still poorly understood, which necessitates a search for optimal experimental ALF models with features resembling those of the human disorder. Taking into consideration reproducibility of induction of ALF, adequate animal size, cost of animals, the required time gap between insult and death of animals (“therapeutic window”), potential risk to investigator and other aspects, administration of thioacetamide (TAA) in rats is currently most recommended. However, the fundamental details of this ALF model have not yet been evaluated. This prompted us to investigate, first, the course of ALF as induced by intraperitoneal TAA at doses increasing from 175 to 700 mg/kg BW per day. The animals’ survival rate, plasma alanine and aspartate aminotransferase activities, and bilirubin and ammonia levels were determined over the follow-up period. Second, we examined whether Wistar and Lewis rats exhibit any differences in the course of ALF induced by different TAA doses. We found that the optimal dose for ALF induction in rats is 350 mg.kg-1 i.p., given as a single injection. Wistar rats proved more susceptible to the development of TAA-induced ALF compared with Lewis rats. Collectively, our present findings provide a sound methodological background for experimental studies aimed at evaluation of pathophysiology and development of new approaches in the therapy of ALF.