MODULATION BY LYMPHOCYTES OF VASCULAR EFFECTS CAUSED BY INFLAMMATORY MEDIATORS AND CARRAGEENIN IN RAT

Abstract

Inhibited permeability responses to intradermally injected histamine, serotonin and bradykinin were observed in leukopenic rats, when compared to those measured in normal animals. Significant reversal of the inhibited responses was seen when leukopenic rats were given suspensions of lymphocytes i.v. Suspensions of PMN [polymorphonuclear] granulocytes were ineffective. In both cases, the volumes of the suspensions contained adequate quantities of the particular cells to counteract their deficiency. Histological changes provoked by carrageenin in the paws of leukopenic rats injected with suspensions of lymphocytes resembled those of normal rats, the main difference being that the number of cells which had emigrated into the affected tissues was reduced. In leukopenic controls or leukopenic animals injected with suspensions of PMN granulocytes, minimal histological alterations were observed. Lymphocytes played a role in the development of acute inflammatory reactions.