Abstract: | The purpose of this study was to determine the effects of the putative cerebral vasodilator, mefenidil hydrochloride (MF), on cardiocirculatory dynamics and the total distribution of cardiac output in the conscious rat. The radioactive microsphere technique was used to measure regional blood flow and cardiac output before (control) and during intravenous infusion of either MF (2.5, 5.0, 10.0 mg/kg) or vehicle (VH; saline, 0.0204, 0.0408. 0.0816 ml/min, respectively). Neither MF nor VH were found to have significant effects on cerebral blood flow or vascular resistance in conscious rats. MF significantly increased cerebral blood flow and lowered cerebral vascular resistance compared to VH in anesthetized animals without having significant effects in other circulatory regions. |