[Distribution of lipoproteins in the human aorta wall]

Localization of lipoproteins of high, low and very low density in the wall of human aorta was studied by an indirect immunofluorescence technique using antibodies to apoproteins (apo) A-I, B-100 and C-III. Apo A-I and apo C-III were distributed relatively evenly through the thickness of the vessel without visible damage, with some prevalence in the zone of lipid infiltration. Apo B-100 were revealed in significant amount in the intima if their content in the aortic media was low. The content of apo A-I and apo C-III was somewhat increased in the lipid strip. Massive deposits of apo B-100 which were frequently distributed unevenly were found in the fibrous plaque. Pretreatment of nonfixed cryostat sections with saline solution containing bovine serum albumin produced a diffused decrease in the intensity of specific fluorescence this being due to the release of lipoproteins from the tissues. The mechanism of the low density proteins accumulation in the aorta, their binding to the vascular wall components is discussed.