Assay of kinins by their effects on canine femoral blood flow.

In pentobarbital anesthetized dogs, close arterial injections of bradykinin and kallidin elicit a dose related increase in femoral blood flow. Treatment with the kininase inhibitor BPP9alpha augments the femoral blood flow responses to bradykinin and kallidin by five and threefold respectively. The sensitivity of the preparation permits the detection of 0.5-1 ng of either bradykinin or kallidin in untreated dogs and as little as 0.1 ng of kinin peptides in animals receiving BPP9alpha. This sensitivity and the steepness of the dose response curves make this procedure suitable for the assay of kinins.