A ACTH

Cosytntropin alpha 1-24 corticotropin (a ACTH subunit), synthetic... 

Fig. 7. An experiment showing the efficiency of fractional precipitation by ammonium sulfate in assays for oxytocin (O—O, A—A), ACTH (0—0, A—A) or insulin (0—0, A—A). With oxytocin there is a substantial gap between the concentration of ammonium sulfate required to precipitate bound antigen and the concentration that will precipitate free antigen. By contrast, with insulin there is virtually no gap and the procedure would not be suitable for an assay. From Chard. ...

A. ACTH acts by activation of adenylate cyclase and production of cAMP. Inhibition of cAMP breakdown synergistically increases the intracellular response to this hormone. 

R. Schwyzer, P. Sieber, Total synthesis of adrenocorticotrophic hormone. Nature (Lond.) 199 172-174 (1963) P. Sieber, W. Rittel, B. Riniker, Die Synthese von menschlichem adrenocorticotropem Hormon (a -ACTH) mit revidierter Aminosauresequenz. Helv. Chim. Acta 55 1243-1248 (1972)... 

Bajusz, S., K. Medzihradszky, Z. Paley, and Zs. Lang Total Synthesis of Human Corticotropin (a-ACTH). Acta Chim. Acad. Sci. Hung. 52, 335-341 (1967). 

In the anterior pituitary gland (see Hormones, anteriorpituitaryhormones), both adrenocorticotropic hormones (ACTH) and the endogenous opiate hormone, P-endorphin, are synthesized from a common prohormone (2) (see Opioids,endogenous). In the adrenal medulla, five to seven copies of another opiate hormone, methionine—enkephalin (Met-enkephalin), and one copy of leucine—enkephalin (Leu-enkephalin) are synthesized from each precursor molecule (3). 

Control of secretion of anterior pituitary hormones also includes inhibition by hormones produced by target organs. For example, CRH stimulates the anterior pituitary to secrete ACTH, which in turn stimulates the adrenal cortex to secrete corticosteroids. Corticosteroids then feed back to inhibit the secretion of ACTH. Feedback mechanisms are important for the control of most hormones. For example, insulin (qv) secretion from the pancreas increases in response to increased blood glucose resulting from ingestion of a meal. Insulin increases tissue uptake and metaboHsm of glucose, which lowers blood glucose and in turn reduces insulin secretion. 

P-Endorphin. A peptide corresponding to the 31 C-terminal amino acids of P-LPH was first discovered in camel pituitary tissue (10). This substance is P-endorphin, which exerts a potent analgesic effect by binding to cell surface receptors in the central nervous system. The sequence of P-endorphin is well conserved across species for the first 25 N-terminal amino acids. Opiates derived from plant sources, eg, heroin, morphine, opium, etc, exert their actions by interacting with the P-endorphin receptor. On a molar basis, this peptide has approximately five times the potency of morphine. Both P-endorphin and ACTH ate cosecreted from the pituitary gland. Whereas the physiologic importance of P-endorphin release into the systemic circulation is not certain, this molecule clearly has been shown to be an important neurotransmitter within the central nervous system. Endorphin has been invaluable as a research tool, but has not been clinically useful due to the avadabihty of plant-derived opiates. 

In humans, the hypothalamic-derived protein and the hormone noncovalent complexes are packaged in neurosecretory granules, then migrate along axons at a rate of 1 4 mm/h until they reach the posterior pituitary where they are stored prior to release into the bloodstream by exocytosis (67). Considerable evidence suggests that posterior pituitary hormones function as neurotransmitters (68) vasopressin acts on the anterior pituitary to release adrenocorticotropic hormone [9002-60-2] (ACTH) (69) as well as on traditional target tissues such as kidneys. Both hormones promote other important central nervous system (CNS) effects (9,70). 

Endorphin (143) is produced from pto-opiomelanocottin, a precursor for a-, P-, and y-melanocyte stimulating hormones (MSH), adtenocorticotropin (ACTH), which includes the a-MSH sequence, and P-Hpotropin (P-LPH), which includes P-MSH and P-endotphin sequences. 

Pregnenolone is transported from the mitochondria to the ER, where a hydroxyl oxidation and migration of the double bond yield progesterone. Pregnenolone synthesis in the adrenal cortex is activated by adrenocorticotropic hormone (ACTH), a peptide of 39 amino acid residues secreted by the anterior pituitary gland. 

---