[Compensatory renal hypertrophy after nephrectomy in newborn rats].

The process of the kidney compensatory hypertrophy in young rats has been studied after nephrectomy on the 2nd day of life. The intact kidney was investigated by morphometrical and electron microscopical methods from the 1st day till the 3rd month after operation. The kidney compensatory hypertrophy in the early postnatal ontogenesis is accompanied by the acceleration of growth and differentiation of renal structures. The hypertrophy involves three successive steps: (1) functional tension of ultrastructures; (2) expressed hyperplasia and hypertrophy of cells; (3) structural-functional specialization. Among the cellular factors of the kidney compensatory growth at this age, the main role is played by the process of cell hyperplasia.