Bradykinin Inhibition by Serum from Animals Subjected to Thermal Injury 1

Summary

A substance appears in postburn serum and edema fluid of animals (rats, rabbits) subjected to thermal burn that inhibits the action of bradykinin on smooth muscle. It has not been detected in normal serum. Evidence suggests that it is not enzymatic in nature, and not a kininase. Ultrafiltration studies indicate that the inhibitor has a molecular weight of over 50,000. The substance appears to be confined to two fractions of the serum, alpha₂-globulin and albumin. Presumably the inhibitor acts by combining with bradykinin, therefore, antagonizing its action on the receptor site of the muscle.