[Intracortical and juxtamedullary nephrons of the kidney during postnatal ontogenesis in rats].

Intracortical and juxtacortical nephrons from the kidney of the male rats (Wistar) at the age of 5-30 days were isolated by means of microdissection technique. In the rat kidney, besides superficial and juxtamedullar nephrons there are 5 more populations of the intercortical nephrons. The development of these nephrons during postnatal rat ontogenesis is accompanied by a considerable increase both of their general length and the length of their segments. Correlation changes between different nephronal segments during the first month of life is determined by their uneven development, that is seen in a relative decrease of the distal segment, a considerable increase of the nephronal loop, its distal segment in particular, at a practically constant length of the proximal segment.