Effect of osthole on electrocardiogram and hemodynamics in anesthetized dogs

The effects of osthole (Ost) 7.5 and 15 mg �� kg-1 iv on electrocardiogram and hemodynamics were studied in 8 anesthetized dogs. Ost significantly decreased systolic blood pressure, diastolic blood pressure, left ventricular systolic pressure, +dp/dt(max) in a dose-dependent manner, lowered total peripheral vescular resistance (TPVR) and moderately decreased cardiac output, while heart rate remained unchanged. Ost 7.5 mg �� kg-1 did not influence electrocardiogram, but 15 mg �� kg-1 of Ost slightly lengthened P-R interval which was accompanied by a decrease in -dp/dt(max). These results indicate that Ost dilates vessels, decreases TPVR and lowers arterial pressure and on the other hand it decreases cardiac pump function to a certain extent.