[Effect of anisodamine on cochlear blood flow in living guinea pigs]

Anisodamine is commonly used in clinic as vasodilator. In the present study, the effects of anisodamine on cochlear blood flow were investigated in living guinea pigs using intravital microscopic techniques. The results showed that intravenous infusion of anisodamine (10mg/kg, 5mg/kg, 2 mg/kg) produced a dose dependent reduction in blood pressure. Large dose (10mg/kg) caused significant decrease in blood flow rate to 68.7 +/- 7.4% of the control value with no significant change in vessel diameter. On the other hand, medium and small doses (5mg/kg, 2mg/kg), which produced relatively smaller reduction in blood pressure caused no significant alternation in blood flow rate and vessel diameter. Also, when intramuscular, infusion of anisodamine (2mg/kg) was used no significant difference in blood flow rate, vessel diameter as well as blood pressure were found. The results indicated that increase in cochlear blood supply can not be induced by anisodamine in normal guinea pigs.