ABSTRACT
Objective: To investigate the expression and effect of secreted frizzled-related protein 5 (sFRP5) in rat's cardiomyocyte hypertrophy in vitro. Methods: Neonatal rat's ventricular myocytes were cultured in vitro, cardiomyocyte hypertrophy was induced by Ang Ⅱ. Telmisartan and PD123319 were used to block angiotensin type 1 receptor (AT1R) and angiotensin type 2 receptor (AT2R) respectively. RT-PCR and Western-blot analysis were conducted to examine the expressions of sFRP5, BNP and TNF-α. Results: sFRP5 was expressed in cardiomyocytes. The mRNA and protein expressions of sFRP5, protein expression of BNP were increased by prolonged time of AngⅡ treatment, the maximum expression was observed at 48 h, P<0.05. Compared with Ang Ⅱ (10-6mol/L) group, the mRNA and protein expressions of sFRP5 in Ang Ⅱ +Telmisartan (10 μmol/L) group were decreased, P<0.05, those expressions were similar in Ang Ⅱ +PD123319 (10 μmol/L) group, P>0.05. Compared with AngⅡ (10-6 mo1/L)+sFRP5 (0 ng/ml) group, protein expressions of BNP and TNF-α were decreased inAng Ⅱ (10-6 mo1/L)+sFRP5 (10 ng/ml) group and in Ang Ⅱ (10-6 mo1/L)+sFRP5 (100 ng/ml) group respectively, P<0.05. Conclusion: For in vitro process of Ang Ⅱ induced neonatal rat's cardiomyocyte hypertrophy, using Ang Ⅱ receptor could up-regulate sFRP5 expression and sFRP5 plays an important role in cardiomyocyte hypertrophy.