The role of platelet factor (PF-4) in the haemostatic-coagulation System

Abstract

(1) Platelet factor 4 (PF-4) wich shows antiheparin activity was purified from the human platelets. After homogenization by sonifier and Al(OH)3 gel absorption, crude PF4 was further purified by the Heparin-Sepharose affinity column chromatography and G-75 sephadex gel filtration. Final PF-4 activity was 186% and purification fold was 500. The purified PF4 neutralized 200u/ml of heparin. The molecular weight of final PF4 was found to be about 20, 000.(2) In normal rabbits a single injection of 2000r endotoxin, extracts of gastric cancer tissue, anti-rabbit platelet immune guinea pig serum and a subsequent infusion of normal saline induced disseminated intravascular coagulation (DIC). The remarkable changes of platelet count and PF4 levels were observed. In contrast to these facts, in the thrombocytopenic rabbits treated with Busulfan DIC was not induced by the infusion of the same trigger substances and PF4 levels did not change dominantly.(3) The relationship of PF4 to haemorrhagic tendency in the patients with DIC, hypoplastic anemia and ITP was investigated. PF4 levels increased markedly in the haemorrhagic patients with DIC and hypoplastic anemia, but it decreased in the patients with ITP. In all cases it was observed that when platelets counts increased and haemorrhage was relieved, PF4 levels became to normal. PF4 would be a good parameter to reflect the platelet function in haemorrhagic disorders and thromboembloic diseases.