Inhibition of plasma kininase activity at slightly acid ph.

Kinins, like bradykinin, are rapidly inactivated in blood and interstitial fluid by an enzyme called kininase. The action of this enzyme was found to be inhibited at slightly acid pH although the formation of kinins proceeded normally. Thus a slightly acid pH which is known to occur in inflamed and damaged tissue is a suitable environment to allow accumulation of kinins which are thought to be the mediators of the inflammatory response.