Effects of albumin infusion on renal function in the dog

¹ Department of Physiology, Indiana University School of Medicine, Indianapolis, Indiana

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_HH2O 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.

Note:
With the Technical Assistance of Issac Womack II