Anticoagulant Activity of the Indian Cattle Leech

Abstract

THE anticoagulant activity of leeches has been known for a long time. Haycraft¹ obtained a saline extract of the anticoagulin from the head of a leech, and found that a dose of 0.01 mgm. would prevent the normal coagulation of 50 ml. blood for four and a half hours. Various investigators have since employed different techniques in their study of the anticoagulant action of leech extract. In our experiments with the common Indian cattle leech (Hirudinaria), an extract of the anticoagulant substance was prepared from the first eight segments of the body of the leech. The tissues were pounded with pure quartz sand in a mortar and the solution filtered through a cotton plug, freed from protein and buffered to pH 7.2 with Sørensen phosphate buffer.