Corticotropin releasing factor

Corticotropin-releasing hormone (CRH), originally named corticotropin-releasing factor (CRF), and also called corticoliberin, is a polypeptide hormone involved in the stress response.

CRH is produced by neuroendocrine neurons in the paraventricular nucleus of the hypothalamus and is released from neurosecretory nerve terminals of these neurons into the blood vessels of the hypothalamo-hypophysial portal system, at the median eminence. These blood vessels carry the released CRH to the anterior lobe of the pituitary, where it stimulates corticotrope cells to secrete ACTH and other biologically active substances (for example &beta;-endorphin). CRF also stimulates the production of ACTH. Release of ACTH is affected by serum levels of cortisol and leptin, by stress, and by the sleep/wake cycle

CRH receptors are also present ar many different sites in the brain, and CRF released from nerve endings within the brain acts as a "neuromodulator", or "neurohormone". For example, CRH receptors are found within the paraventricular nucleus itself, the central nucleus of the amygdala, the bed nucleus of the stria terminalis, and at the locus coeruleus.

CRH is also synthesized by the placenta and seems to determine the duration of pregnancy.

The 41-amino acid sequence of CRH was first determined by Shibahara et al in 1983.


 * Ser - Glu - Glu - Pro - Pro - Ile - Ser - Leu - Asp - Leu - Thr - Phe - His - Leu - Leu - Arg - Glu - Val - Leu - Glu - Met - Ala - Arg - Ala - Glu - Gln - Leu - Ala - Gln - Gln - Ala - His - Ser - Asn - Arg - Lys - Leu - Met - Glu - Ile - IleNH2

Reference

 * Shibahara S, Morimoto Y, Furutani Y, Notake M, Takahashi H, Shimizu S, Horikawa S, Numa S. Isolation and sequence analysis of the human corticotropin-releasing factor precursor gene. EMBO J 1983;2:775-9. PMID 6605851.