Definition of Corticotropin-releasing hormone

Corticotropin-releasing hormone: A hormone made by the hypothalamus that stimulates the release of corticotropin by the anterior pituitary gland. Corticotropin-releasing hormone is abbreviated and often referred to as CRH.

CRH is chemically classed as a neuropeptide hormone -- a protein-like molecule made up of a short chain of amino acids produced in the brain that functions as a hormone.

The hypothalamus where CRH is produced is an area of the brain that also controls body temperature, hunger, and thirst.

The anterior pituitary where CRH acts is the front portion of the pituitary, a small gland in the head. It secretes hormones that influence growth, sexual development, skin pigmentation, and thyroid function, as well as the function of the adrenal cortex.

Prodded by CRH, the anterior pituitary releases corticotropin which travels down to the adrenal cortex (the outer part of the adrenal gland), stimulating its growth and its secretion of corticosteroids (cortisone-like hormones). Corticotropin is also called adrenocorticotropic hormone (ACTH).

CRH is normally released by the mother and the embryo soon after the embryo implants in the uterus (womb). The function of the CRH appears to protect the embryo from immunologic rejection by the mother. Without CRH, the embryo may be rejected by the mother, resulting in a miscarriage (spontaneous abortion).