Plasma cofactors necessary for Enhydrina schistosa (beaked sea snake) venom to induce platelet aggregation.

A study of the effect of the venom of the beaked sea snake (Enhydrina schistosa) was undertaken on platelet aggregation. It was found that platelet aggregation and the release reaction occurred in the presence of both venom and plasma but, not with the venom alone. No effect was observed with fixed platelets distinguishing the effect of the venom from that of platelet aggregation with ristocetin or botrocetin and indicating metabolic dependence. Studies to elucidate the plasma factor required for platelet aggregation under the release reaction indicated dependence on the presence of both Factor II and calcium ions. This venom may prove to be a useful laboratory reagent in coagulation studies because of the Factor II and calcium dependence.