[Effects of transmural pressure on the transport and distribution of low density lipoproteins in the arterial wall].

In an attempt to investigate the effects of transmural pressure on LDL transport and distribution across the arterial wall, uptake of labeled LDL has been measured in excised rabbit thoracic aorta, held at in vivo length and pressurized to 70 or 160 mmHg. The transmural distribution of LDL concentration across the wall was determined by examining serial frozen sections cut parallel to the luminal surface at 20 microns intervals from the intima to adventitia. The LDL concentration observed in the first luminal section at 160 mmHg was 20-fold higher than that obtained at 70 mmHg. The LDL concentrations decreased in the subsequent sections of the first half of the media and became similar, in the outer half of the media, to the values observed under normal pressure. These results might provide an account of one of the mechanisms involved in the deleterious effects of hypertension in atherogenesis.