Role of bradykinin in exudative reactions of inflammation in rats.

This study was done with the aid of experimental models of inflammation provoked in air pouch, which was made subcutaneously on the back of rats, by applying a carrageenin solution or a suspension of kaolin in a carboxymethylcellulose solution as an irritant. Bradykinin in the inflammatory sites, determined by an enzyme immunoassay method, were comparatively high in the earliest stage of inflammation in both the models and responsible for the exudative reactions. With the passage of time, i.e. within 20 min in the case of kaolin and 120 min in carrageenin, tissue kininase entered the inflammatory site and reduced bradykinin to a very low level, though bradykinin was still being generated very actively. In this later stage, bradykinin collaborates with prostaglandin to bring about a significant increase in the vascular permeability.