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.
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Teikyo University, Kanagawa, Japan.
J
J
Kurihara
N
N
Oda
H
H
Kato
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002561:Cerebrovascular Disorders / Q000503:physiopathology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D005444:Flunarizine / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D002546:Ischemic Attack, Transient / Q000503:physiopathology*; D008297:Male; D010208:Papaverine / Q000494:pharmacology; D011311:Pressoreceptors / Q000187:drug effects*; D012018:Reflex / Q000187:drug effects*
D010208:Papaverine; D005444:Flunarizine