Summary.  Experiments on 40 white non-linear immature (l-month old) male rats evaluated  indices of  renal function with sublimate nephropathy at loading by 3% sodium chloride solution in volume of 5% of the body weight under conditions of  blockade of renal prostaglandins production with indomethacin and had shown inhibition of diuresis, decrease of sign of the syndrome of sodium ions loss with urine against the background of hypernatremia. Disorders of glomerular-tubular balance were characterized by the loss of positive correlative dependences of relative reabsorption of water with  glomerular filtration, filtrative fraction and absolute reabsorption of sodium ions. The defined changes in glomerular-tubular balance in sexually immature rats with sublimate nephropathy under the 3% solution of sodium chloride loading to the extent of 5% of body mass under the condition of blocking the production of kidney prostaglandins by indomethacin with the loss of positive correlation dependence of the relative water reabsorption on glomerular filtration, filtration fraction and absolute reabsorption of sodium ions, confirm the effect of the prostaglandins on the above processes in immature rats. The decrease of the compensatory abilities as to the development of the syndrome of sodium ions loss in immature rats in experiment leads to the disorders of sodium homeostasis and to the development of hypernatraemia.

Key words: sublimate nephropathy, loading by 3% sodium chloride solution, indomethacin, immature rats.