The development of the ovine fetal adrenal gland and its regulation

In mammalian species, the fetal adrenal gland plays a key role during late gestation since fetal glucocorticoids are involved in the maturation of the fetus and in the adaptation of the neonate to extra-uterine life. Moreover, in domestic ruminants as well as in the pig, the onset of parturition is triggered by an increased level of fetal plasma glucocorticoids. This prepartum rise of fetal glucocorticoids, which conveys growth and differentiation of adrenocortical cells, is not only under pituitary control but also involves local regulations. We review the actual knowledge of the modalities of fetal adrenal development in the sheep and its regulation by the adrenocorticotropic hormone (ACTH) and other factors.