Influence of Kallikrein on the Cerebral Blood Flow in Rabbits

Chung, Chang Oh; Lee, Yong Gwang; Woo, Jung Hyun

Abstract

It is known that in animals with increased intracranial pressure the cerebral perfusion is curtailed, but whether it is caused by deranged responsiveness of the cerebral vessel is not known. Thus, it was attempted in this study to find out the changes of cerebrovascular response to Kallikrein in the rabbits with increased ICP(20mmHg) under urethane-anesthesia. 1) intracarotid arterial kallikrein elicited increases in cerebral blood flow and decreases in blood pressure and arterial resistance. 2) Cerebral blood flow was significantly decreased in rabbits with increased ICP in comparison with the control rabbits. 3) Intraarterial kallikrein caused dose-depent increases of cerebral blood flow in both groups, but responses were significantly reduced in ICP-elevated group. 4) Kallikrein produced dose-dependent hypotensive effect in both groups with no significant difference between both groups. 5) Cerebrovascular resistance was greater in rabbits with elevated ICP(20 mmHg), but kallikrein induced decreases of cerebrovascular resistance in both groups to the same degree, 6) Above results suggested that increased ICP reduces the cerebral blood flow by increasing cerebrovascular resistance, but it does not modify the reponsiveness of cerebral vessel to kallikrein.