A comparison of renal function following the infusion of Ringer solution into systemic and portal veins in the dog.

The increase of sodium and water excretion by the kidney following intravenous Ringer solution infused into a femoral vein (vena femoralis) or into an intestinal vein (vena portae ) has been studied in anaesthetized dogs. The functional parameters of renal function have been compared during volume expansion with 1.5-2.0% of body weight Ringer solution and "over-hydration" by 2.5% Ringer loading over 60 minutes. No significant difference in sodium excretion and urine output resulted from 0.25 ml/kg/min Ringer solution when infused by the two routes. When the animals were infused with 2.5% body weight Ringer solution (0.66 ml/kg/min i.v.), a marked increase in water excretion was observed with a smaller increment in sodium excretion, and the urine became hyposmotic as compared with the plasma osmolarity. No difference has been found in the glomerular filtration rate and in the PAH clearance. Glomerular filtration rate, sodium excretion and urine flow rate were not significantly different for the two routes when the same Ringer solution load was infused. These experiments did not provide evidence for the participation of the liver in the control of sodium excretion during extracellular fluid volume expansion induced by Ringer solution infusion.