RESUMO
<p><b>OBJECTIVE</b>To study the effect of tanshinone II A on the cell signal transduction system protein kinase B (Akt) in rats with hypertrophy of the myocardium induced by partial constriction of the thoracic aorta.</p><p><b>METHODS</b>Rat models of myocardial hypertrophy were established by the thoracic aorta partial constriction method. Forty-eight rats were randomly divided into the sham-operative group, the model group, the valsartan treatment group, and the low-, medium-, and high-dose tanshinone treatment groups. The heart mass index (HMI), left ventricular mass index (LVMI), ejection fraction (EF), left ventricular posterior wall (LVPW), and interventricular septal thickness (IVS) were detected by high-frequency ultrasonography. The myocardial fiber diameter (MFD) was detected by HE staining, and the contents of p-Akt and p-Gsk3beta in the myocardium were detected by Western blot.</p><p><b>RESULTS</b>Compared with the sham-operative group, the levels of HMI, LVMI, LVPW, IVS, and MFD were increased respectively in the other groups (P<0.05); the contents of p-Akt and p-Gsk3beta were also increased in the other groups. Compared with the model group, the levels of HMI, LVMI, LVPW, IVS, and MFD were decreased respectively in all treatment groups (P<0.05); the contents of p-Akt and p-Gsk3beta were decreased in all treatment groups as well. There was no significant difference, however, among the low-, medium-, and high-dose tanshinone treatment groups and the valsartan treatment group (P>0.05).</p><p><b>CONCLUSION</b>Tanshinone II A can prevent myocardial hypertrophy by its action on the protein kinase B (Akt) signaling pathway.</p>