A-Corticotropin

B3. Barbarion, A., de Marinis, L Tofani, A., Casa, S. D D Amico, C., Mancini, A., Corsello, S. M Sciuto, R, and Barini, A., Corticotropin-releasing hormone inhibition of gonadotropin release and the effect of opioid blockade. J. Clin. Endocrinol, Metab. 68,523-528 (1989). 

Rassnick S, Heinrichs SC, Britton KT, Koob GF. 1993. Microinjection of a corticotropin-releasing factor antagonist into the central nucleus of the amygdala reverses anxiogenic-like effects of ethanol withdrawal. Brain Res 605(1) 25-32. 

Potter E, Behan DP, Linton EA, et al The central distribution of a corticotropin-releasing factor (CRF)-binding protein predicts multiple sites and modes of interaction with CRF. Proc Natl Acad Sci USA 89 4192-4196, 1992... 

Stress contributes to the development of food allergies by increasing transepi-thelial permeability in a corticotropin-releasing hormone (CRH)-dependent fashion (Yang et al. 2005). 

Fig. 15. Titration data for the phenolic groups of a-corticotropin, at 25°C and ionic strength 0.1, plotted according to Eq. (14) (L5onis and Li, 1959).

An entirely different situation exists in the titration of a-corticotropin (Leonis and Li, 1959). Data for the phenolic groups, obtained in 0.1 M KCl, are shown in Fig. 15. A straight line is obtained, but w is only 0.034 instead of the value of 0.16 expected at that ionic strength from Table III. This difference is far outside the limits of error of the calculation. 

This is the most likely explanation for the low values for w which are obtained for a-corticotropin. The titration curve therefore suggests that this molecule exists in water in an unfolded rather than a compact globular conformation. This conclusion is supported by measurement of hydro-dynamic properties of a-corticotropin. 

It is clear from this discussion that the measurement of volume changes which accompany titration of proteins and of model compounds represents a potentially fruitful area of research. It would be of special interest to have available AF values for synthetic polypeptides (or for naturally occurring substances such as a-corticotropin), which exist in aqueous solutions in a randomly coiled conformation. 

The first experimental criteria to be met in a spectrophotometric titration are that the absorptivities be time-independent, and reversible. This is so fundamental that it should be obvious, but it still must be stressed. Proteins not infrequently possess marked alkali-sensitivity, as shown by the inactivation of pepsin at pH 7, the hydrolysis of one particular amide linkage in a-corticotropin at pH 9 (Shepherd et al, 1956), and the irreversible inactivation of bacitracin at pH > 7 (Weisiger et al, 1955). 

Peptides have been studied chiefly as a step toward the understanding of the much more complicated substances, the proteins. However, peptides are extremely important compounds in their own right the tripeptide glutathione, for example, is found in most living cells the nonapeptide oxytocin is a posterior pituitary hormone concerned with contraction of the uterus a corticotropin, made up of 39 amino acid residues, is one component of the adrenocorticotropic hormone ACTH. 

Pseudohypericin has been shown to be a corticotropin-releasing factor (CRF), receptor antagonist. CRF has been implicated as a pathogenic factor in affective disorders, with elevated levels that are normalized after treatment with antidepressants found in the cerebrospinal fluid of patients with depression. CRF acts on CRFX receptors in the pituitary gland to stimulate the release of adrenocoticotropic hormone, which stimulates the release of glucocorticoid stress hormones from the adrenal glands (19). It is possible that St. John s wort s activity comes from pseudohypericin s ability to block the CRFX receptor. 

Grossman A. Corticotropin-releasing hormone Basic physiology and clinical applications. In DeGroot LJ, ed. Endocrinology. Philadelphia WB Saunders Co, 1995 341-54. 

Theoharides, T.C., Spanos, C., Pang, X., Alferes, L., Ligris, K., Letoumeau, R., Rozniecki, J.J., Webster, E., and Chrousos, G.P., Stress-induced intracranial mast cell degranulation A corticotropin-releasing hormone-mediated effect. Endocrinology, 136(12), 5745,1995. 

A 4-year-old girl with an XO genetic genotype A 4-year-old boy with chronic renal failure and growth deficiency A 10-year-old boy with polydipsia and polyuria A 37-year-old AIDS patient who is 180 cm tall and weighs 52 kg Hormones that are useful in the diagnosis of endocrine insufficiency include (A) Corticotropin-releasing hormone Cosyntropin... 

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