ABSTRACT
AIM: To investigate the expression of connective tissue growth factor (CTGF) in the myocardium of spontaneously hypertensive rats and the relationship of the hypertensive ventricular remodeling, myocardial fibrosis and whether irbesartan alter this expression. METHEDS: 20 twenty-week-old male spontaneously hypertensive rats were randomly assigned to SHR group and irbesartan group (n=10 in each), and 10 twenty-week-old male Wistar Kyoto rats were considered as WKY group. Rats in irbesartan group were given a daily dose of 50 mg?kg~-1 irbesartan for 12 weeks by gavage and the other two groups were fed with a normal diet. TGF-?1 and CTGF were evaluated by qualitative and semiquantitative immunohistochemical staining and semiquantitative reverse transcription polymerase chain reaction. MASSON staining were used in the study of total collagen in left ventricular interstitial tissue. RESULTS: Compared with the WKY group, the left ventricular wight index(LVI), collagen volume fraction (CVF), perivascular collagen area (PVCA) and the expression of TGF-?1, CTGF and its mRNA in left ventricular increased in SHR group (P
ABSTRACT
Objective To investigate the regulation effect of irbesartan on the expression of angiotensin-converting enzyme 2 (ACE2) mRNA in the kidney of spontaneously hypertensive rats (SHR). Methods Twenty 14-week-old male SHR were randomly divided to SHR group (n=10) and irbesartan group (n=10); ten 14-week-old male WKY group were served as control. Irbesartan group was given a daily dose of 50 mg/kg irbesartan for 12 weeks by gavage and the other two groups were fed with a normal diet. ACE2 in kidney was examined by immunohistochemistry and RT-PCR. Plasma angiotensin II in each group were estimated by radioimmunoassay (RIA). Results The ACE2 mRNA expression was significantly down-regulated in the kidney of SHR group compared with WKY group (0. 72?0. 11 vs 1. 11?0. 15). After 12 weeks treatment with irbesartan, the attenuated ACE2 expression in irbesartan group was markedly enhanced compared with SHR group (1. 03?0. 13 vs 0. 72?. 0. 11). ACE2 mRNA expression in SHR kidney was correlated significantly with plasm angiotensin II level. (r = 0. 83, P
ABSTRACT
AIM: To investigate the expression of angiotensin-converting enzyme 2 (ACE_2) in the renal of spontaneously hypertensive rats and the effects of angiotensin type-1 receptor blockade. METHODS: Twenty of 14-week-old male SHR were randomly divided into two groups (n=10 in each): SHR group and irbesartan group. Ten of 14-week-old male WKY group were served as control. Irbesartan group were given a daily dose of 50 mg?kg -1 irbesartan for 12 weeks by gavage and the other two groups were fed with a normal diet. Angiotensin-converting enzyme 2 was examined by immunohistochemistry and RT-PCR. RESULTS: ACE_2 in the renal was significantly down-regulated in the SHR group compared with the WKY group ( 0.72? 0.11 vs 1.11? 0.15). After 12 weeks treatment with irbesartan, the attenuated ACE_2 expression in irbesartan group was markedly enhanced compared with the SHR group ( 1.03? 0.13 vs 0.72? 0.11). CONCLUSION: Hypertension induces the reduction of ACE_2 in the renal in rats and irbesartan markedly increases ACE_2 expression. It suggests that up-regulation ACE_2 which is one of counter-regulatory particular components in the renin-angiotensin system may be a new mechanism of curing hypertension beyond blockade angiotensin type-1 receptor.