Influence of experimental stenosis on uptake of albumin by the abdominal aorta.

The influence of abdominal aortic stenosis on the uptake of the protein-binding trypan blue dye and 131I human serum albumin (HSA) has been studied. The major change was a region of high uptake proximal to the stenosis, returning to normal by the level of the renal arteries. There was reduced uptake distal to the stenosis, apart from occasional small areas of high uptake probably due to turbulence. The increase in uptake immediately proximal to the stenosis was dependent on the severity and duration of the stenosis. Removal of the stenosis immediately before the injection of dye and 131I-HSA still resulted in elevated uptake in the proximal region. Some haemodynamic modifications resulting from a stenosis are described. It is suggested that the most satisfactory haemodynamic explanation of the observed uptake change is a proximal increase in oscillatory pressure/strain. The relevance of these findings to atherosclerotic development at and above arterial junctions is discussed.