A single dose of fifty milligrams of ω-heparin (1mg of body weight) newly isolated from the whale lung and intestine was injected intravenously to volunteers. The change of coagulating activity was followed up by the throm-belastogram. Comparing with beef-heparin, ω-heparin was found to have more potent anticoagulant activity and longer duration of the effect at the same dose level. The prolongation of the coagulation time was still observable 6 hours after the use of ω-heparin, while beef-heparin lost its effect within 4 hours.
Neutralization test by protamine sulfate showed that ω-heparin could not be completely neutralized by the same dose of protamine sulfate and a light anticoagulant activity remained after 1:1 neutralization.