Sex differences in adrenocortical structure and function. XVI. Stereological and karyometric studies on the cortex of the suprarenal gland of intact adult male and female Mongolian gerbils (Meriones unguiculatus).

The histological structure of intact adult male and female Mongolian gerbil (Meriones unguiculatus) suprarenal cortex has been described, and quantitative stereological and karyometric studies were performed. The weight of the gland relative to body weight was higher in female than in male gerbils, but the volume of the gland was similar in both sexes. The relative volume of the zona reticularis was higher in the female, while no sex difference was observed in the absolute volume of all suprarenal components (expressed in mm3). In all cortical zones, average cell volume was higher in the female; the nuclear volume of the zona glomerulosa and zona reticularis were also higher in the female. In the zona fasciculata, some large cells with large nuclei (greater than 210 micrometers 3) were observed. These are probably polyploid cells and have not been described in other species. The suprarenal cortex of the male gerbil contained more parenchymal cells than that of the female, the difference being dependent upon variation in the number of cells in the zona fasciculata and zona reticularis. Despite these structural differences, gland homogenates from male and female animals secreted similar amounts of cortisol and the plasma levels in the two sexes were the same.