Effects of albumin infusion on renal function in the dog

Abstract

Serum albumin (25%) was infused into anesthetized dogs undergoing a saline diuresis. No significant effect was seen on arterial pressure, but renal venous pressure was elevated slightly. GFR remained unchanged, while C pah , renal plasma flow, total renal blood flow, and flow to medullary tissue increased significantly. Accompanying these changes were marked declines in PAH and creatinine extraction ratios. Urine volume, C na , and C osm declined appreciably during albumin infusion; T c H H2 O tended to decrease. The ratio of Na and osmolar constituents in renal venous blood to that in arterial blood increased above unity, and calculations indicated that at this time Na was washed from the kidney. Tm pah remained unchanged during albumin infusion. It is concluded that during albumin infusion, there is an increase in plasma volume and renal blood flow accompanied by a diversion of part of this blood through aglomerular regions, possibly through A-V anastomoses, as evidenced by the accompanying decrease in E cr and E pah . This could involve increased perfusion of the medullary papillary zone, including the vasa recta vessels, supported by the observations that during albumin infusion there is a washout of osmotic constituents, primarily Na, presumably from a zone of high Na concentration.