Summary: The effects of the anti-inflammatory drugs, mepyramine maleate, SQ-10643, pyridinol-carbamate and indomethacin were tested on the exudative responses evoked by cold injury to the skin of the rat.
The initial increase in vascular permeability occurring in the first [alpha] hour after freezing is significantly suppressed by antagonists of histamine or 5-hydroxytryptamine, whereas, antagonists of kallikrein and the kinins have no effect. Exudation during the 2nd hour after injury is unaffected by all 4 drugs, but during the period 3 1/2-4 1/2 hours after freezing is partially suppressed by antagonists of kallikrein and the kinins. After severe freezing, suppression is obtained when the delayed and initial responses are replaced by a strong monophasic response. It is concluded that the initial permeability evoked by cold injury is mediated by histamine and 5-hydroxytryptamine and that delayed exudation is due to endogenous mediation by kallikrein and/or the kinins, as well as to direct vascular damage.
(C) 1973 Royal College of Pathologists of Australasia