Sex dimorphism in the adrenal of hamsters.

Abstract

ABSTRACT The adrenals of the hamster differ in many respects from those of other mammals that have been studied so far. The higher weight and the higher steroid secretion of the male adrenal are conspicuous features. The adrenals of 144 Syrian golden hamsters between the 1st and 12th week of life were studied histologically and histometrically in order to see whether these sex differences also show up in the morphology of the adrenals. Histologically in both sexes a typical zonation in glomerulosa and fasciculata could be observed from the 2nd week onwards. Both zones consist of compact cells. Already at the end of the 4th week in some sections, sex-specific differences are found. From the 5th week up to the end of our experiment these differences are so pronounced that it is possible with 100% accuracy to determine the sex of the animal from the appearance of the adrenal: the zona reticularis of the female adrenal shows a higher cellularity than in the male adrenal. In males on the other hand, the cells are arranged less densely and development of intracellular vacuoles in the adjacent fasciculata and in the zona reticularis are seen. The histilogical sex differences are significant from the end of the 4th week up to the end of our study. Parallel with the histological changes a difference in the weights of the adrenals begins to appear from the 4th week onwards. The male adrenal glands are heavier than those of females. This weight difference can be confirmed statistically from the 6th week onwards. The studies provided a morphological basis for the reticularis of the adrenals of golden hamsters for the sex-specific function and weight.