[Possible participation of vessel wall kinins in regulating blood vessel tonus]

Extracts of mammalian arterial walls revealed a kinin-like biological activity resistant against proteolytic inactivation with trypsin but not chymotrypsin. Bradykinin was chromatographically determined as kinin existing in extracts from the rat aorta. Kallidin was found as well as bradykinin in human vessels. Metabolism of vasoactive kinins in the vascular wall seems to take part in control of circulation and blood pressure.