Seasonal study of the adrenal gland of some Indian avian species.

Adrenal glands of eight Indian species of birds, namely Columba livia, Passer domesticus, Corvus splendens, Acridotheres tristis, Acridotheres ginginianus, Milvus migrans, Francolinus pondicerianus and Bubulcus ibis were examined during the sexually active and inactive phases of their annual reproductive cycles. Excepting A ginginianus and M. migrans, among members of either sex of the remaining six species the weight of the adrenal gland increases during the period of sexual activity. Histologically, the interrenal tissue of these birds could be divided into a peripheral subcapsular zone and a central zone. The cytochemical content of these two zones varies between sexual activity and inactivity. In sexually active birds of both sexes, interrenal cells of the central zone exhibit an increased concentration of alkaline phosphatase, glycogen, acid mucopolysaccharides and gross lipids, while in the subcapsular interrenal cells there is a prominent increase of ascorbic acid content. Cytochemical contents of chromaffin cells remain unchanged except acid phosphatase, which increases during the sexually active phase.