On the Administration of Heparin Per os

Abstract

In, view of the possibility of using heparin in the prevention of thrombosis any information concerning the physiology of that substance is of considerable importance. For the inhibition of the clotting of blood in vivo heparin is applicated by intravenous injection. 1 With reference to the chemical resistance of heparin and the reported excretion of it in the urine 2 it was thought possible to apply it orally.

Heparin with the activity k = 3,4 and prepared as described before 3 was dissolved in water (10 mg per cc). Mice were then given 0.5 cc from a syringe with a special glass tube inserted through the mouth in the stomach. Blood was obtained by cutting the tail. None of the mice in the experiments showed any delayed clotting of the blood, notwithstanding the great amounts of heparin given. There were, therefore, the following two possibilities: (1) Heparin is inactivated in the alimentary tract, or (2) it is not absorbed by the organism.

To prove which is the case, mice were given heparin in the same manner as before, and during the following 5 days the feces was collected at intervals. It was then extracted with 0.50 cc of water per 10 mg of feces, centrifuged and the supernatant liquid tested for inhibitory action in the usual manner. To 5 drops of chicken plasma one drop of the fluid was added, and the clotting time by the addition of a drop of chicken thrombokinase was observed in a water-bath at 39°. 4

In Table I two of the 9 experiments are described. The chicken plasma clotted, with the addition of thrombokinase only, in 1 1/2 min. The experiments show that the heparin passes the alimentary tract without deterioration.