Kallikreins

enzymes of blood plasma and the tissues of certain organs (kidney, pancreas, salivary glands, intestinal walls) that catalyze a reaction in which the quinines bradykinin and kallidin split off from the inactive protein precursor quinino-gen.

Kallikreins are enzymes of the trypsin type. They have ex-tremely narrow specificity and manifest biological activity char-acteristic of the quinines. A preparation of kallikreins from swinepancreas is used as a vasodilator, especially in disorders of peri-pheral blood circulation.