Studies in Vascular Permeability of Human Skin Bradykinin

Abstract

Intradermal injections of 7.5 meg of bradykinin into normal human skin produced wheals of 5 to 8 mm diameter, which grew for a period of 6 min., reaching eventually the size of 10 to 16 mm and persisted up to 6 hr. 75% of the test subjects experienced pain at the site of injection which lasted from 3 to 6 min. In some of those, the pain started only after a latent period of several minutes, and then persisted for a considerably longer period. Two subjects felt pruritus in addition to pain, while some felt neither pain nor itch. Serial dilutions of bradykinin and histamine were injected into the skin of the back of 182 inmates of a mental institution. The size of the resulting wheals and the intensity of bluing, after intravenous injection of Coomassic blue was recorded. The following bradykinin antagonists were tested with respect to their capacity of altering the intensity of bluing: cyproheptadine, methdilazine, guanethidine, trasylol, EACA [epsilon amino caproic acid] acetyl salycilic acid and glucose. Only methdilazine was capable of inhibiting the permeability changes produced by bradykinin.