Abstract
Nocodazole, a microtubule inhibitor, was tested for its effects on aggregation and release in human platelets. Nocodazole inhibited only the release reaction induced by ADP or ristocetin and inhibited the aggregation and release reaction induced by the other reagents tested (collagen, thrombin, adrenaline, polylysine, lectins [WGA and RCA], arachidonic acid, A23187, and PAF).
Nocodazole had no effect on the intracellular calcium release induced by thrombin which was measured by the decrease of the fluorescence of chlortetracycline. The drug inhibited the MDA generation of platelets induced by collagen, and it also inhibited the release of arachidonic acid from the phospholipids in the membrane.
From these results, nocodazole was indicated to inhibit the release reaction of platelets, and one of the steps inhibited by this drug was suggested to be at the level of the phospholipases.
