EFFECT OF HYPERLIPIDEMIC DIETS, PROINFLAMMATORY AGENTS AND PLASMA EXPANDERS ON LEUKOCYTE ADHESION TO THE ENDOTHELIUM OF AORTA AND CAROTID-ARTERY OF RATS

A comparative study of leukocyte adhesion to the endothelium of the th oracic aorta and left carotid artery in rats has been performed after administration of two hyperlipidemic diets for 15 days, proinflammator y agents (thrombin, lipopolysaccharide and zymosan activated serum) an d plasma expanders [dextran, polyvinylpyrrolidone (PVP), rat albumin a nd several bovine albumins from different sources]. Leukocytes adhered to the endothelium were. demonstrated in surface preparations by este rase activity. Activation of circulating leukocytes was measured by ni troblue tetrazolium reduction and luminol enhanced chemiluminescence. Both hyperlipidemic diets produced, in all rats, more leukocyte adhesi on in the aorta than in the carotid artery. All proinflammatory agents produced at 1 h, increases in leukocyte adhesion - which in all rats were greater in the carotid artery than in the aorta - and leukocyte a ctivation, which was higher at 3 h than at 1 h. Dextran, PVP, bovine a lbumins 103700 and A-4503 at 18 h produced slight increases in leukocy te adhesion in the aorta but not in the carotid artery. Rat albumin an d bovine albumin A-7906 determined an intense leukocyte adhesion at 18 h which was not preferential to either vessel. Adhesion produced by A -7906 was maximal at 12 h and partially inhibited by dexamethasone. Th is last albumin produced leukocyte activation at 3 h and was sequester ed 5 min after administration, reaching normal values at 1 h. Albumins 103700 and A-4503 neither activated leukocytes nor were sequestered a fter administration.