Increased central and peripheral glucocorticoid synthesis act as an orchestrator of developmental programming

Physiological challenges experienced during development can alter lifetime function as a result of Developmental Programming. Gene environment interactions in developmental programming are receiving growing interest due to their effects as major determinants of lifetime health. This chapter considers commonalities and differences between precocial and altricial species in relation to the hypothalamo-pituitary-adrenal axis. It focuses on the roles of glucocorticoids both as immediate and long-term mechanisms in the responses to the challenges that give rise to programming. Profound changes occur in fetal and neonatal glucocorticoids in both altricial and precocial species that are involved in maturing organs in preparation for an independent post-natal life. At the other end of the life-course there is no clear agreement as to changes in the HPAA. Interestingly maternal age at conception may affect the rate of aging of the offspring HPAA. Evidence is presented of increased peripheral production of cortisol by 11-Betahydroxysteroid dehydrogenase 1 in both sheep and baboons in response to poor maternal nutrition. Finally we address recent data that indicate that glucocorticoids are involved in the programming of the post natal leptin peak that itself programs appetitive behavior. This collection of evidence suggests that their ubiquitous impact on multiple organ systems indicates that glucocorticoids are central orchestrators of many aspects of developmental programming.