Adrenocorticotropic hormone action

Drugs with unknown mechanism of action are gabapentin, bromides (but see above effects on GABAergic transmission) and adrenocorticotropic hormone (ACTH), which is used in infantile spasms. 

Schimmer, B.P. and Parker, K.L., Adrenocorticotropic hormone adrenocortical steroids and their synthetic analogs inhibitors of the synthesis and actions of adrenocortical hormones, in Goodman and Gilman s The Pharmacological Basis of Therapeutics, 9th ed., Hardman, J.G. and Limbird, L.E., Eds., McGraw-Hill, New York, 1996, chap. 59. 

Nickel ions have been shown to depress the in vivo and in vitro release of prolactin [336], while the release of growth hormone was stimulated, and only at relatively high ion concentrations. Hyperglycemia occurs in rats following intraperitoneal or intratracheal injections of NiCl2 [265, 337, 338], The mechanism of action of nickel appears to be inhibition of insulin release this inhibition could be related to the extremely high concentration of nickel found in the pituitary and the effect on the secretion of the pituitary hormones (growth hormone and adrenocorticotropic hormone). 

Corticotropin (adrenocorticotropic hormone, ACTH) regulates the function of the adrenal cortex and has numerous other effects on metabolism. It contains 39 amino acids in the form of a random coil, owing to the presence of several proline residues that prevent helix formation. Species differences are seen in amino acids 25-39 the rest of the ACTH molecule is identical in all animals and humans. The first 24 amino acids are responsible for all of the biological action of ACTH synthetic human ACTHj 24 is known as cosyntropin. 

Schimmer BP, Parker KL. Adrenocorticotropic hormone adrenocortical steroids and their synthetic analogs inhibitors of the synthesis and actions of adrenocortical hormones. In Brunton LL, et al, eds. 

Secretion and actions of adrenocorticotropic hormone (ACTH). CRH, corticotropin-releasing hormone. 

Schimmer BP, Parker KL (1995) Adrenocorticotropic Hormone Adrenocortical Steroids and Their Synthetic Analogs Inhibitors of the Synthesis and Actions of Adrenocortical Hormones. In Hardman JG, Limbird LE (eds) Goodman Gilman s The Pharmacological Basis of Therapeutics, 9th Edition. McGraw-Hill, New York, pp 1459-1485 Sullivan AT, Kinter LB (1995) Status of safety pharmacology in the pharmaceutical industry 1995. Drug Dev Res 35 166-172... 

Fig. 3. Summary of key mechanisms of action through which a model adrenotoxicant (indicated by a black star) could disrupt the synthesis of corticosteroids. References presenting data in support of this model are given in the text. ACTH, adrenocorticotropic hormone Rc, receptor G, G-protein AC, adenylyl cyclase Ca, calcium ATP, adenosine triphosphate cAMP, cyclic adenosine monophosphate PKA, protein kinase A StAR, Steroid acute regulatory protein SCC, P450SCO, cholesterol side chain cleaving enzyme 11/3, 11/3-hydroxylase 17a, 17a-hydroxylase 3/3-HSD, 3/3-hydroxysteroid-5A-steroid dehydrogenase C21, 21-hydroxylase ER, endoplasmic reticulum.

Melatonin occurs in the pineal gland and is the biochemical clock in the brain (Bartsch 1994). Various forms of mental illness may respond to melatonin therapy Maurizi 1984) (Brown 1995). Melatonin blocks the actions of melanocyte-stimulating and adrenocorticotropic hormones (Axelrod). There are several synthetic methods used to produce melatonin (Szmuszkovicz 1959), Metabolism of melatonin see (Kopin 1961) (Kveder 1961). 

Hormones, see also under Steroids and under names of individual hormones activity, mechanism of, X, 331 adrenocortical, see under Adrenocortical hormones and under names of individual hormones adrenocorticotropic, see under Adrenocorticotropic hormone assay in obstetrics, X, 141-181 diabetogenic action, X, 185, 196-206 gonadotropic, see under Gonadotropins and under names of individual members... 

The actions of hormones are very diverse. Some, e.g. glucagon, have specific and clearly defined effects on the metabolism of particular tissues. Others such as growth hormone and the sex hormones have more general effects on growth and development while the tropic hormones stimulate their target tissues to secrete further hormones. For example the adrenocorticotropic hormone (ACTH), which is produced in the anterior pituitary, promotes the synthesis and release of glucocorticoids by the adrenal cortex. A list of some of the hormones and their effects on metabolism is given in Table 24.1. 

---