[Character and frequency of pathologic changes in the single kidney of rats following removal of the other in old age].

Unilateral nephrectomy was performed in male rats weighing 500--850 g; the remaining kidney underwent compensatory hypertrophy which in rats weighing 700--850 g proved to be higher in 1 to 2 months than in the animals weighing 500--600 g (hypertrophy index--70--92 and 56--58%, respectively). Histological examination demonstrated that such a marked hypertrophy of the single kidney in senile rats was not the result of its sickness, since pathological changes, sometimes encountered in the intact and hypertrophied kidneys were revealed in 38 of 223 animals. The data obtained permit to suppose that the compensatory -restorative capacity of the kidneys fails to diminish in senile animals.