HORSE SPECIES SYMPOSIUM: Glucocorticoid programming of hypothalamic-pituitary-adrenal axis and metabolic function: Animal studies from mouse to horse.

Adrenal glucocorticoids, such as cortisol, are essential for normal fetal development and for maintaining homeostasis in adults. Developmental studies in humans and other animals have shown that exposure to excess glucocorticoids during critical windows of perinatal development can program permanent changes in hypothalamic-pituitary-adrenal (HPA) axis function and metabolic function, with adverse implications for the long-term health of the exposed offspring. The current review compares the programming of postnatal HPA axis function and glucose homeostasis among different species overexposed perinatally to glucocorticoids, with emphasis on the horse. The potential role of epigenetic modification of genes involved in the regulation of HPA axis and metabolic function at cellular and molecular levels is also discussed.