Increase in vascular permeability of rat and guinea pig skin by T-kinin

The vascular permeability-increasing response to T-kinin in rat and guinea pig skin was investigated. The vascular permeability was measured with 125I-labeled bovine serum albumin [( 125I]BSA) as a tracer. Plasma exudation rapidly occurred 0-15 min after the intradermal injection of T-kinin. T-kinin in doses of 0.3, 1, and 3 nM/spot significantly increased the vascular permeability in a dose-dependent manner. The vascular response of T-kinin is similar to that of bradykinin. On the other hand, T-kinin analogs, D-Ile-Ser-bradykinin and Ile-D-Ser-bradykinin only weakly enhanced the vascular permeability. Prostaglandin E1, forskolin, and the angiotensin-converting enzyme inhibitor, SQ-14225, potentiated the T-kinin-induced plasma exudation. Cyproheptadine and indomethacin did not affect the T-kinin-induced response. The results suggest that T-kinin will play an important role in increasing vascular permeability associated with inflammation.