Anticoagulant effects of sulphonated polyisoprenes.

Sulphonated polyisoprenes (SPIPs) having various molecular weights and sulphonate group contents were synthesized and their anticoagulant activities investigated. Prolongation of blood clotting time, prothrombin time and activated partial thromboplastin time were observed in the presence of SPIPs. The anticoagulant activity in blood was affected mainly by total sulphonate group concentration; however, the molecular weight of SPIPs also had an influence. Since thrombin time was prolonged by SPIPs for a condition which supplied enough thrombin to the assay system, interactions between fibrinogen and SPIPs may be one of the anticoagulant mechanisms of SPIPs.