Sex steroid application reverses changes in rat castration cells: Unbiased stereological analysis

Abstract

The aim of the present study was to examine the morphometric characteristics of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) immunoreactive cells in the pituitaries of orchidectomized (Orx) and Orx testosterone- or estradiol-treated rats. Adult male Orx Wistar rats, 2 weeks post operation, received estradiol dipropionate (E) or testosterone propionate (T) for 3 weeks. Both controls, sham-operated (So) and Orx rats, were injected with solvent, in the same regime. Changes in the volume of pars distalis, the volumes of individual FSH- and LH-labeled cells, their numerical density and number were determined by unbiased design-based stereology. The FSH and LH intracellular content was estimated by relative intensity of fluorescence (RIF). We observed that Orx caused hyperstimulation of gonadotropic cells. Their volume, volume density, number, numerical density and intracellular hormone content significantly increased in comparison to So controls. Compared to Orx controls, T caused a significant decrease in the volume and volume density of gonadotropic cells and immunoreactive FSH and LH content in their cytoplasm. The volume of the pars distalis, the numerical density and number of gonadotropic cells were not changed as compared to Orx controls. Estradiol treatment caused a significant increase in the volume of the pars distalis, decreases in cell volume, volume and numerical density of gonadotropic cells, and FSH and LH intracellular content in comparison to Orx controls. The number of FSH-labeled cells increased. In conclusion, both T and E reversed all of the examined parameters of gonadotropic cells of Orx rats to the level of So controls, except in number.