Programming of endocrine mechanisms of cardiovascular control and growth.

Several epidemiologic studies have linked size at birth to health in adult life. One school of thought centers on the part that periconceptual or intrauterine events play in this relationship. The idea is that an event, or several events, during critical periods of development can program, or permanently alter, fetal physiology resulting in altered size at birth and subsequent adult disease, including that of the cardiovascular system. Maternal diet or body composition at the time of conception can influence placental development and subsequent transfer of nutrients and substrates to the fetus. Alterations to the maternal diet or body composition throughout gestation are then seen as challenges that are superimposed on this backdrop of periconceptual events. One task is to find an animal model that replicates the major features of the epidemiologic data: for adult cardiovascular disease this would be altered fetal size and the development of postnatal hypertension. In addition, a critical issue is to investigate the mechanisms underlying this Fetal Origins of Adult Disease hypothesis. The multiple mechanisms that constitute fetal cardiovascular responses to hypoxia in late gestation at neuronal, endocrine, and local tissue levels have been studied extensively, and there is evidence from several different experimental paradigms that these control mechanisms can be programmed by intrauterine challenges. This review synthesizes the current knowledge in this area and considers how the programming of cardiovascular control relates to fetal growth.