Effects of insulin on calcium metabolism and platelet aggregation
Ishida, M.; Ishida, T.; Ono, N.; Matsuura, H.; Watanabe, M.; Kajiyama, G.; Kambe, M.; Oshima, T.
Hypertension 28(2): 209-212
1996
ISSN/ISBN: 0194-911X PMID: 8707383 Document Number: 468603
The influence of insulin on platelets in vitro has not been exhaustively investigated. To clarify whether insulin affects Ca-2+ metabolism in platelets directly or through alteration of other systems regulating intracellular Ca-2+ homeostasis, we examined the effect of insulin both alone and in combination with prostaglandin E-1 on platelet aggregation and Ca-2+ metabolism. Incubation of rat platelets with insulin reduced thrombin-induced Ca-2+ influx but did not change thrombin-evoked release of Ca-2+ from internal stores or the size of internal Ca-2+ stores. The interactive effects of insulin with prostaglandin E-1 were only additive, and insulin did not augment the effects of prostaglandin E-1 on platelet Ca-2+ metabolism. In contrast, insulin did not inhibit thrombin-induced platelet aggregation but did augment inhibition of platelet aggregation by prostaglandin E-1. Our results suggest that insulin inhibits platelet function by both prostaglandin E-1-dependent and -independent mechanisms.