A Histological Study of the Adrenal Gland in Aged Cows.

The knowledge of the endocrine glands in aged animals seems necessary in the understanding of the relationship of endocrine glands to the whole organism. Most of our knowledge concerning the senile changes are based on the findings from laboratory animals . Meanwhile, reports concerning the ageing process of the endocrine glands of domestic animals are especially few. The present study is concerned with the histological changes in the adrenal glands from three aged cows. The important facts in a histology of the bovine adrenal gland are that the adrenal cortex is characteristically lipid-poor and that the glomerulosa cells specifically contain abundant acidophil granules . It has been noted repeatedly in cattle that parallel conclusions similar to those in lipid-rich laboratory animals in respect to the histophysiology of the zona glomerulosa are hard to obtain . The frequent age changes observed in the adrenal such as the proliferation of connective tissue, an appearance of pigment granules and a local degeneration have been reported in a various animal species (B lumen t h a 1, '59; Jayne , '53, '57; Meyer s and Char i p p e r, '56 ; Pa y n e, '52). Working with rats , Jayne ('53) found a general decrease in cortical lipid content with increasing age. Meanwhile, Me y e r s and C h a r i p per ('56) reported an appearance of lipid material with an advancement of age in the hamster adrenal cortex. Weber et al . ('56, '58, '59) postulated in their studies working with cattle that the zona glomerulosa is inactivated in those cases where oil red 0 stainable lipid droplets appear. With regard to pigment granules, Jayne ('57) found them in