Receptor and non receptor-mediated activation of blood platelets. Effect on membrane-cytoskeleton interaction.

Platelets were activated by receptor and non receptor-mediated reagents. The effect of these reagents on aggregation, secretion, cytoskeleton formation, interaction of alpha-actinin and other membrane proteins with the cytoskeleton was studied. Results show that receptor-mediated activation (e.g. ADP or thrombin activation) leads to a high extent of association of alpha-actinin with the cytoskeleton while non receptor-mediated activation (e.g. ionophore A-23187, arachidonic acid) leads to a low association between the two species. The degrees of aggregation, secretion and total amount of protein in the two modes of activation were the same.