Renal excretory function after renal denervation and administration of diuretics to unanaesthetized dogs evaluated by a mathematical model for describing the dynamics of the excretory process

Abstract

A mathematical model has been employed for describing the cumulative curve of excretion after diuretic administration. The program, developed in accordance with the model and the criteria of evaluation, allows an easy and rapid comparison of the effects of different kinds of diuretics in different doses. The experiments were carried out prior to and after left kidney denervation in unanaesthetized dogs with exteriorized ureters. Acetazolamide 3.0 mg/kg b.w., Furosemide 0.2 mg/kg b.w. or Amiloride 1.0 mg/kg b.w. were injected intravenously. The amount of excreted urine as well as of sodium, chloride and potassium was studied. No statistically significant differences in the dynamics of renal excretory function between the denervated and innervated kidneys were observed after the administration of Acetazolamide and Amichloride. After Furosemide, the flow-rate during maximum diuresis and the maximum chloride excretion rate were greater in the denervated kidney. No statistically significant differences were noted in sodium excretion. It appears that the greater part of compensatory reabsorption in the distal tubules of the denervated kidney takes place in the zone up to macula densa.