Effects of tanshinoneIIA on the cardiac content of aldosterone and the expression of CYP11B1 and CYP11B2 mRNA related to aldosterone synthesis in spontaneously hypertensive rats

OBJECTIVE To investigate the effects of TanshinoneⅡA on the cardiac content of aldosterone and the expression of genes related to aldosterone synthesis.METHODS 30 male spontaneously hypertensive rats (SHR) and Wistar-Kyoto(WKY) rats were divided into three groups,i.e.control group,hypertension group and TanshinoneⅡA group. The rats in TanshinoneⅡA group were given TanshinoneⅡA for 12 weeks. Radioimmunoassay and reverse transcriptase polymerase chain reaction (RT-PCR) were used to evaluated the cardiac content of aldosterone and the mRNA amount of CYP11B1 and CYP11B2 related to aldosterone synthesis.RESULTS Compared with WKY rats,SHR exhibited higher content of aldosterone and mRNA level of CYP11B1 and CYP11B2(P0.01,P0.05 and P0.01).After treatment with TanshinoneⅡA,the cardiac content of aldosterone and mRNA level of CYP11B2 significantly decreased (P0.01,P0.05 and P0.01).The expression of CYP11B1 gene was similar in three groups.CONCLUSION The inhibition of left ventricular hypertrophy by TanshinoneⅡA might be contributed to its down-regulating effects on CYP11B2 gene expression and aldosterone synthesis.