[Changes in the ultrastructure and fibrogenic activity of rat dermal fibroblasts as affected by various doses of hydrocortisone].

By means of electron microscopical morphometry and populational analysis it has been stated that hydrocortisone acetate, injected subcutaneously twice a week in dose 5 mg/kg of the body mass, produces decrease in number of intensively collagen-producing fibroblasts and increase in the part of fibroblasts and destroying cells in population of fibroblasts only in young (2-week-old) animals. The dose 10 mg/kg produces similar changes both in young and in mature (2-month-old) animals. In the young animals given hydrocortisone in dose 5 mg/kg of the body mass, the mean summational area and extension of the granular endoplasmic reticulum membranes in the fibroblast section diminishes, the summational area of the mitochondrial section decreases in the section of one cell, and the derm with less thickness, in comparison with the derm of intact animals, is formed, while in mature animals, given hydrocortisone in a small dose, all the parameters mentioned do not significantly differ from the control. Hydrocortisone in dose 20 mg/kg decreases all quantitative parameters of dermal fibroblasts both in young and mature animals. The data of the correlative analysis give evidence on the presence of a strong positive connection between inhibition of the synthetic apparatus of fibroblast development under hydrocortisone effect and decrease of the derm thickness, forming during the postnatal period of ontogenesis.