Role of heparin in realization of the hypoglycaemic action of insulin.

A temporary resistance to the hypoglycaemic action of insulin has been found after preliminary binding of heparin in the blood of animals by 1 mg/200 of protamine sulphate (PS). This effect was observed after 5-30 min PS treatment before the insulin injection or endogenous increase of insulin stimulated by sugar load. PS did not influence the concentration of immunoreactive insulin in blood plasma. 2,5-ionene, a synthetic antagonist of heparin, induced temporary resistance to the hypoglycaemic action of insulin. Intravenous injection of heparin in corresponding doses after PS administration restored the hypoglycaemic effect of insulin. The results suggest that the presence in the circulation of reactive heparin may be necessary for insulin reception by the target tissue.