[Comparative study of the ultrastructure of cells of the zona fasciculata of the adrenal cortex of rats of different lines].

By means of morphometric analysis, some tissue and cellular parameters of the zona fasciculata of the adrenal cortex of three rat inbred strains (Wistar, Sprague-Dawley, August) and of the wild grey rats were calculated. Significant genotypic differences were found in the absolute volume in the number of cells per mm3 of tissue, and in relative volumes of basis cellular compartments (smooth endoplasmic reticulum, liposomes) which take part in corticosteroid biosynthesis. A hypothesis is put forward that these differences determine different potential possibilities of rat adrenals, which are realized when their functional activity is enhanced under extreme conditions.