Apparent Similarity of Mechanisms of Platelet Adhesion and Aggregation

Summary

A correlation between effects of a series of compounds on platelet adhesion, aggregation, and retraction of the clot, and their effects on platelet electrophoretic mobility, ecto-ATPase activities, and AChE activity has been sought. Compounds which inhibited aggregation induced by ADP or epinephrine also inhibited platelet adhesion to glass. Six compounds which inhibited adhesion and aggregation did not inhibit clot retraction. The data suggest that the effect of thrombin on platelet electrophoretic mobility and ecto-ATPase activities may have less influence on platelet function than was formerly believed. However, the effects of test compounds on platelet AChE activity suggest that this enzyme may play a role in aggregation and adhesion. Platelet adhesion and aggregation may operate by similar mechanisms.

^* Supported in part by Grants HE-01648 and HE-06350 from the National Heart and Lung Institute, and FR-00164 from the Division of Research Facilities and Resources.

^** Dr. Mason is a Markle Scholar in Academic Medicine and a USPHS Career Development Awardee.

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