Corticotropin-releasing hormone (CRH), originally named corticotropin-releasing factor (CRF), and also called corticoliberin, is a polypeptidehormone and neurotransmitter involved in the stress response.
CRH is produced by neuroendocrine cells in the paraventricular nucleus of the hypothalamus and is released from neurosecretory terminals of these neurons into the primary capillary plexus of the hypothalamo-hypophyseal portal system. The portal system carries the CRH to the anterior lobe of the pituitary, where it stimulates corticotropes to secrete corticotropin (ACTH) and other biologically active substances (for example β-endorphin).
Neurotransmitter actions
CRH receptors are also present at many different sites in the brain, and CRH released from nerve endings within the brain acts as a neurotransmitter. 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.
Role in parturition
CRH is also synthesized by the placenta and seems to determine the duration of pregnancy.
Structure
The 41-amino acid sequence of CRH was first determined by Shibahara et al in 1983. Its full sequence is
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.
