Resistance of vasoactive peptides from venom of Vespa orientalis to action of proteolytic enzymes

The kinetics of the hydrolysis by proteolytic enzymes of vasoactive peptides isolated from the venom of the hornetVespa orientalis has been investigated. It has been found that the half-period of decomposition of the peptides exceeds that of bradykinin. These facts are in harmony with in vivo results on the prolonged hypotensive action of the peptides.