[Cellular mechanisms of compensatory processes of the kidney in relation to the mass resected]. / Kletochnye mekhanizmy kompensatornykh protsessov v pochke v zavisimosti ot massy ee rezektsii.

As a result of comparative investigation of compensatory processes in the kidneys at various degree of their resection, the most general regularities in these processes have been revealed: an initial functional strain of renal cells and their ultrastructures, the secondary increase in hypertrophy and hyperplasia of the renal cells and their organelles. The degree of manifestation of these regular reactions directly depends on the mass of the resected part of the kidney. Subtotal resection of the kidney (80%) is an operation that gets out of the limits of the organ's compensatory possibilities. A sharp decrease, up to complete disappearance of its cellular division in 2-3 weeks after the operation is of great importance. Mechanism for development of renal insufficiency is evidently connected with absence of cellular renewal against the background of their hyperfunction and their quick worn out, that is, evidently, resulted in deficiency of renal epithelium and functional defectiveness connected with it in the remained renal mass.

[Various structural aspects of the functional transformation of the kidneys during adaptation to fasting]. / Nekotorye strukturnye aspekty funktsional'noi perestroiki pochek pri adaptatsii k golodaniiu.

Electron microscopic and morphometric investigations of the rat kidneys in 3-6 days after a complete fasting have revealed certain ultrastructural signs of an increased proteolysis in the proximal parts of the nephron canaliculi and structural manifestation in the glomerular blood stream changes, that represents an important condition for passing proteins the glomerular membrane. In this connection, it is supposed that at adaptation to fasting the kidney ensures proteolysis of endogenic-proteins--the first stage of their reconstruction. This function is ensured by structural-functional reconstruction of the juxtaglomerular complex, vessels of the filtrative apparatus and by the proteolytic system in the proximal part of the nephron canaliculus.

[Compensatory renal hypertrophy after nephrectomy in newborn rats]. / Kompensatornaia gipertrofiia pockhi posle nefrektomii u novorozhdennykh krysiat

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.