RESUMO
<p><b>OBJECTIVE</b>To investigate the effects and mechanisms of Shexiang Baoxin Pill (SBP) on myocardial fibrosis in spontaneous hypertensive rats (SHR).</p><p><b>METHODS</b>SHR of 12 weeks old were divided into the SBP group, the control group (treated with benazepril) and the model control group. The effects on such indexes as systolic blood pressure (SBP), left ventricular mass (LVM), left ventricular mass index (LVMI), content of myocardial collagen (MC) in left ventricle, extracellular matrix fibronectin (FN), laminin (LN), cardiac fibroblast (cFb) and transforming growth factor-beta1 (TGF-beta1) were determined after 12 weeks of treatment.</p><p><b>RESULTS</b>SBP had no marked pressure depressive effect, but had the effect similar to that of benazepril in reducing the level of LVM, LVMI and content of MC (P < 0.05), as well as the content of LN, FN in myocardium, cFb count and TGF-beta1 expression (P < 0.05).</p><p><b>CONCLUSION</b>SBP can prevent and treat myocardial fibrosis, whose action is independent of its hypotensive effect. The mechanism may be associated with such factors as the decrease of MC synthesis in left ventricle and the deposition of extracellular matrix.</p>