Effect of flunarizine on the attenuation of baroreflex by transient cerebral ischemia.

Baroreflex sensitivity assessed by phenylephrine-induced reflex bradycardia was markedly decreased by 5- an 10-min global cerebral ischemia in anesthetized dogs. Flunarizine, 0.1 and 1 mg/kg i.v., administered 5 min prior to 5-min ischemia, completely inhibited the decrease in baroreflex sensitivity while such a protective effect of the latter dose was incomplete against 10-min ischemia. In contrast, papaverine, 0.5 mg/kg per min i.v., infused for 5 min prior to 5-min ischemia, failed to protect the decrease in baroreflex sensitivity. Flunarizine may possess a certain direct cerebroprotective effect in addition to its cerebrocirculatory effect.