Tissue differences in vascular permeability induced by leukortriene B 4 and prostaglandin E 2 in the rat

Abstract

The activity of synthetic LTB 4 and PGE 2, in increasing vascular permeability was tested simultaneously in seventeen different organs in the rat. Rats were injected in the aortic arch through a cannula in the carotid artery with 125-I-albumin, 51Cr-erythrocytes, and 57Co-EDTA. The rats were then injected through the carotid artery cannula with LTB 4, PGE 2 or a combination of LTB 4 and PGE 2. Eight minutes later the rats were killed and the activity of 125I, 51Cr, and 57Co measured in different organs. Changes in vascular permeability were infered from changes in the ratios of the isotope activities. LTB 4 (15 μg/kg) induced enhanced permeability in caecum, small bowel, skin, fat pad, stomach, pancreas, and aorta, but not in the heart, brain, colon, testes, diaphragm, forelimb, cremaster muscle, lung, kidney or eye. A lower dose of LTB 4, 3 μg/kg, enhanced vascular permeability in caecum, small bowel, skin, stomach, and aorta. PGE 2 (1 μg/kg) enhanced vascular permeability only in the caecum. A combination of LTB 4 (3 μg/kg) and PGE 2 (1 μg/kg) was more potent than either alone. Rats depleted of neutrophils with anti-neutrophil serum were less sensitive to LTB 4 than intact rats. These findings suggest that the vasculatures of different tissues in the rat vary markedly in their susceptibility to LTB 4 induced increases in permeability.