TOPICAL PROSTACYCLIN (PGI2) INHIBITS PLATELET-AGGREGATION IN PIAL VENULES OF THE MOUSE

Local application of prostacydin (PGI2) to cerebral (pial) microvessels, inhibited the aggregation of platelets induced in the vessels by exposing them to a filtered mercury light source following intravenous sodium fluorescein. The inhibition was consistantly observed in venules rather than arterioles and was manifest by a lengthening of the time required for the noxious stimulus to produce an initial aggregate, and/or by a lengthening of the time required for enlarging aggregates to totally block the venule. The consistency of the inhibition diminished at doses below 100 μg/ml. Inhibition was observed whether or not alcohol was used as the vehicle for PGI2 and whether or not the body temperature of the anesthetized mouse was permitted to fall. © 1979 American Heart Association, Inc.