Corticotropin-releasing hormone is secreted by the paraventricular nucleus (PVN) of the hypothalamus in response to;stress. Marked reduction in this protein has been observed in association with Alzheimer disease and autosomal;recessive hypothalamic corticotropin deficiency has multiple and potentially fatal metabolic consequences including;hypoglycemia and hepatitis. In addition to production in the hypothalamus, this protein is also synthesized in;peripheral tissues, such as T lymphocytes and is highly expressed in the placenta. In the placenta it is a marker that;determines the length of gestation and the timing of parturition and delivery. A rapid increase in circulating levels;of the hormone occurs at the onset of parturition, suggesting that, in addition to its metabolic functions, this;protein may act as a trigger for parturition.