| THE HYPOTHALAMO-PITUITARY-ADRENAL AXIS
|
| Two hypothalamic peptides are the principal regulators of pituitary ACTH release, corticotropin-releasing hormone (CRH) and vasopressin
|
| Two hypothalamic peptides, CRH and VP/ADH, are the principal but not the sole regulators of pituitary ACTH synthesis and release. They act independently and synergistically. CRH is a 41-amino-acid peptide secreted by the paraventricular nucleus; it acts via the cAMP second messenger system. VP/ADH is a nine-amino-acid peptide synthesized by both the supraoptic and paraventricular nuclei; it acts by altering intracellular calcium ion channels. Negative feedback by cortisol inhibits the stimulation of the pituitary by both CRH and VP/ADH.
|
|
