flunarizine and Hyperemia

Cerebral blood flow in the rat was monitored by a venous outflow technique with an extracorporeal circulation, which allows for the continuous recording of flow over periods of several hours. The bi-fluorophenyl-piperazine derivatives, lidoflazine and flunarizine, enhanced the reactive hyperemia elicited by a brief (30 s) anoxic challenge. They did not alter resting cerebral blood flow rates. Verapamil, a potent calcium slow channel blocker, decreased resting flow rates but did not alter the duration of the reactive hyperemia. As lidoflazine and flunarizine are potent inhibitors of adenosine uptake, whereas verapamil is not, the results are consistent with the hypothesis that adenosine plays a significant role in cerebral vascular autoregulation.

Topics: Animals; Blood Gas Analysis; Cerebrovascular Circulation; Cinnarizine; Extracorporeal Circulation; Flunarizine; Hyperemia; Hypoxia; Lidoflazine; Male; Piperazines; Rats; Rats, Inbred Strains; Verapamil