Effects of organotins on rat platelets.

Incubation of rat platelets with organotins inhibited their capacity to take up 5-hydroxytryptamine-14C (5-HT-14C) and stimulated the release of preloaded 5-HT-14C as well as endogenous 5-HT. Similar but less pronounced effects also were observed when platelets from rats treated intraperitoneally with organotins were examined. The relationships of organotin structure to 5-HT uptake inhibition and 5-HT release were similar, with the most active compounds being the trisubstituted derivatives bis(tri-n-butyltin) oxide, tri-n-butyltin chloride, tricyclohexyltin hydroxide, tri-n-propyltin chloride, and triphenyltin hydroxide. Scanning electron micrographs revealed increased platelet aggregation and shape change in organotin treated samples as compared to vehicle treated controls. It was suggested that the action of organotins on rat platelets was due, at least in part, to their known ability to interfere with ATPase mediated systems.