Abstract: Objective To investigate the mechanism of secreted frizzled-related Protein 5 (sFRP5) expression in cardiomyocyte hypertrophy. Methods In vivo experiment, neonatal rat ventricular myocytes were exposed to Ang II（10-6mmol/L, 48h）. Telmisartan, Y27632, PD98059，SB203580 and SP600125 were used to block angiotensin type 1 receptor(AT1R), Rho/ROCK, p38 MAPK, ERK1/2 and JNK pathway, respectively. Western blot was to determine the expressions of sFRP5, ROCK1, ROCK2, total MYPT1, p-MYPT1, total JNK and p-JNK. RT-PCR was used to determine sFRP5 expression. Results Our experiment confirmed that there were significant inhibition of sFRP5 expression when treated with Y37632 and SP699125, but less with SB203580 and PD98059 in Ang II-induced cardiomyocytes. Moreover, telmisartan down-regulated the expression of ROCK1, but had no effect on the expression of ROCK2. Conclusions The expression of sFRP5 was up-regulated mainly by Rho/ROCK1/JNK pathway in cardiomyocyte hypertrophy induced by Ang II.

Key words: Secreted frizzled-related protein 5, Angiotensin II, Cardiomyocyte, hypertrophy, JNK pathway