PROTEIN-KINASE-C INHIBITOR, CHELERYTHRINE, POTENTIATES THE ADRENALINE-MEDIATED AGGREGATION OF HUMAN PLATELETS THROUGH CALCIUM INFLUX

The role of protein kinase C (PKC) using its selective inhibitor, chel erythrine, in agonist mediated platelet aggregation was studied. Chele rythrine had no effect on the aggregation induced by adrenaline, PAF, collagen and ADP at the maximum doses of these agonists. However, it p otentiated the aggregatory reponse of low doses of adrenaline (0.4-1 m u M). Such an effect was blocked by Ca++-channel blockers, verapamil a nd diltiazem indicating the likely involvement of Ca++ influx in the p latelet aggregation during the cascade.