Differences in the mode of exucative reaction between early phase and late phase of carrageenin-induced inflammation in rats.

Differences in the mode of vascular permeability change induced by some stimulants such as chemical mediators between the early phase and the late phase of the carrageenin-induced granulomatous inflammation were investigated with the aid of 131I-human serum albumin as an indicator for the measurement of vascular permeability. In the early pregranulomatous phase of the inflammation, histamine injection into the inflammation locus markedly elevated local vascular permeability, while prostaglandins E1 and E2 showed no effect. On the other hand, in the late phase of the inflammation, where permanent granuloma tissue had been formed, prostaglandins E1 and E2 significantly enhanced the local vascular permeability, while histamine was inert.