[Juxtaglomerular apparatus and interstitial cells of kidney medulla in hydronephrosis and chronic pyelonephritis].

Light and electron microscopic examinations of biopsies of the renal cortex were carried out in 24 patients with chronic pyelonephritis and 12 patients with hydronephrosis, as well as of the medullar substance in 7 of these patients after nephrectomy. A detailed analysis of the processes of granule formation in epithelioid cells of the juxtaglomerular apparatus (JGA) using the previously reported method of mathematical evaluation of the shape of granules (ellipticity) established a moderate direction correlation between the ellipticity of the granules and the level of proteinuria. Signs of activation were found in intact JGA: an increased amount of diamondshaped protogranules. The number of lipid granules decreased in interstitial cells of the medullar substance. In exacerbations of chronic pyelonephritis and experimentally, degenerative and necrotic changes were found in interstitial cells due to edema and infiltration of the medullar substance with polymorphonuclear leukocytes and lymphocytes.