Pharmacological demonstration of inflammatory mediators using experimental inflammatory models: rat pleurisy induced by carrageenin and phorbol myristate acetate.

Rat pleurisy induced by carrageenin or phorbol myristate acetate (PMA) was utilized for examination of the plasma exudation process of inflammation. Chemical mediators responsible for induction of vascular permeability increase were examined. In carrageenin-induced pleurisy, kinin and PGl2 were demonstrated as the main mediators, and in PMA pleurisy histamine, PGI2 and platelet-activating factor were the main mediators. These results indicate that different stimuli may activate different enzymatic processes to produce different mediators, but they may result in similar inflammatory reactions by action of these multiple mediators simultaneously released.