Effect of splanchincotomy on the renal excretion of inorganic phosphate in the anaesthetized dog.

The effects of acute i.v. inorganic phosphate (Pi) loading were studied on nembutalized mongrel dogs previously subjected to unilateral splanchnicotomy ("renal denervation"). GFR (51Cr-EDTA) was not different on the intact and the denervated side, while urine output (V), sodium excretion (UNaV), and urinary excretion (UPiV) of inorganic phosphate of denervated kidneys were significantly increased at any plasma Pi level. Thus, tubular reabsorption of Pi in denervated kidneys was considerably depressed. Tubular transport rates of Na and Pi--as expressed in per cent of the filtered load--were positively correlated in both intact and denervated organs. Besides an impairment in tubular transport of Na a depression in the reabsorption of inorganic phosphate is brought about by renal denervation. A common mechanism of action for both Na and Pi can be supposed.