Zonal mitotic response in the adrenocortical tissue of the juvenile female duck to sex hormones.

The zonal response of the adrenocortical tissue to sex hormones was evaluated in the female duckling by mitotic (with colchicine) and histological studies. Estrogen (1 mg per bird daily for 10 days), progesterone (1 mg per bird daily for 10 days) or estrogen plus progesterone (0.75 mg plus 0.25 mg respectively per bird daily for 10 days) selectively inhibited mitosis in the central zone of the adrenocortical tissue. Histologically, estrogen or estrogen plus progesterone produced hypertrophy in the subcapsular zone, while progesterone caused atrophy in the central zone of the cortex. It is suggested that both the sex hormones have zonal action mitotically as well as histologically in the adrenocortical tissue of the female duckling.