Stroke, Vol 18, 792-795, Copyright © 1987 by American Heart Association
EF Ellis, ML Heizer, GS Hambrecht, SA Holt, JM Stewart and RJ Vavrek
We have previously shown that topical brain application of kallikrein, an
enzyme which converts kininogen to bradykinin, induces rabbit pial
arteriole dilation. The purpose of the present investigation was to utilize
a newly developed competitive kinin receptor antagonist to test the
hypothesis that kallikrein-induced dilation was due to the conversion of
brain kininogen to vasoactive kinins. As in our previous study, we measured
rabbit pial arteriole diameter with a microscope using the closed cranial
window technique. The kinin antagonist (6 microM) reduced the
dose-dependent dilation produced by bradykinin and blocked the dilation
induced by kallikrein. In addition, the kinin antagonist was specific since
it did not alter the cerebral arteriole dilation produced by adenosine,
acetylcholine, or vasoactive intestinal polypeptide. These experiments
provide further evidence for a possible role of the endogenous brain
kallikrein-kinin system in the modulation of the cerebral circulation and
provide the necessary pharmacologic foundation for future use of this
antagonist in testing the role of kinins in the normal or altered cerebral
circulation.
ARTICLES
Inhibition of bradykinin- and kallikrein-induced cerebral arteriolar dilation by a specific bradykinin antagonist
|
Stroke Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 1987 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |