The effect of renal arterial infusion of albumin and dextran on tubular fluid reabsorption in the dog.
Albumin or Dextran solutions of varying concentration were infused into the renal artery of hydropenic dogs. Their effect on urine flow, sodium excretion, creatinine and PAH clearance, single nephron GFR, fractional and absolute fluid reabsorption in the proximal convolution, reabsorptive t1/2, and hydrostatic pressures in the proximal tubules and adjacent capillaries was compared with a similar infusion of isotonic saline solution. Six, 9, 12, 18 and 25% albumin and 6% Dextran solution did not significantly change the measured parameters. Infusion of 9 and 12% Dextran solution elicited a decrease in water and sodium excretion as well as absolute and fractional proximal tubular fluid reabsorption to a 5% level of significance. Infusion of 18% Dextran was accompanied by a marked decrease in total and proximal reabsorption combined with a decline of GFR, PAH clearance, and hydrostatic pressures in tubules and peritubular capillaries. The results do not support the hypothesis of a direct action of oncotic pressure on tubular fluid reabsorption; the above described effects of Dextran seem to be accounted for by its other "pharmacological" effect.
D000042:Absorption; D000418:Albumins / Q000008:administration & dosage*; D000818:Animals; D001826:Body Fluids / Q000378:metabolism; D003911:Dextrans / Q000008:administration & dosage*; D004285:Dogs; D007261:Infusions, Intra-Arterial; D007684:Kidney Tubules / Q000187:drug effects* / Q000378:metabolism; D012077:Renal Artery
D000418:Albumins; D003911:Dextrans