Structure prolactin

Freeman ME, Kanyicska B, Lerant A, Nagy G (2000) Prolactin structure, function, and regulation of secretion. Physiol Rev 30 1523-1631. 

M. E. Freeman, B. Kanyicska, A. Lerant, et al. Prolactin structure, function and regulation of secretion. Physiological Reviews 80, 1523 (2000). 

Structure—function relationships of prolactin among a variety of species have been pubUshed (17,18). Only one gene for prolactin appears to exist (19). Although classically placed in the category of simple protein hormones, prolactin can be glycosylated. Carbohydrate attachment occurs at Asn-31, where the consensus glycosylation sequence Asn—X—Ser is found. 

The prolactin receptor, PER, which regulates milk production in mammals, belongs to the same receptor class as the growth hormone receptor. In addition to binding the hormone prolactin, PER also binds and is activated by growth hormone. The extracellular domain of PER forms a very stable 1 1 complex with growth hormone in solution this complex has been crystallized and its structure determined (Figure 13.21). We shall compare this structure with the 1 2 complex of the same hormone with GHR. 

Headache and compromised or loss of vision caused by the prolactin-secreting tumor and its close proximity to the optic structures. 

A vast number of hormones and neurotransmitters are synthesized from simple structural units including chains of amino acids. Among the amino acid based hormones are comparatively large protein molecules such as prolactin, growth hormone and insulin, and shorter chains of amino acids which may form peptide hormones, such as oxytocin and vasopressin. Protein based hormones are essential for metabolism, growth and some components of reproduction. However, evidence for specific influences of these compounds on human behavior is limited. 

Cahoreau C, Gamier L, Djiane J, Devauchelle G, Cerutti M (1994) Evidence for N-glycosylation and ubiquitination of the prolactin receptor expressed in a bacu-lovirus-insect cell system. FEBS Lett 350 230-234 Caplan S, Green R, Rocco J, Kurjan J (1991) Glycosylation and structure of the yeast MF a 1 a-factor precursor is important for effident transport through the secretory pathway. J Bacteriol 173 627-35... 

Human prolactin is similar in structure to human growth hormone, and both are good lactogens. In women, prolactin acts with other hormones on the mammary gland during pregnancy to develop lactation and after birth to maintain it. Hyperprolactinemia causes impotence in men and amenorrhea and infertility in women. Chronically elevated levels of circulating prolactin are associated with suppression of 17-p-estradiol and testosterone production in the ovaries and testes. 

McCance SL, Cohen PR, Cowen PJ Dthium increases 5-HT-mediated prolactin release. Psychopharmacology 99 276-281, 1989 McCann U, Hatzidimitriou G, Ridenour A, et al Dexfenfluramine and serotonin neurotoxicity further prechnical evidence that chnical caution is indicated. J Pharmacol Exp Ther 269 792-798, 1994 McCarley RW REM sleep and depression common neurobiological control mechanisms. Am J Psychiatry 139 565-570, 1982 McCarley RW, Hobson JA Neuronal excitability modulation over the sleep cycle a structural and mathematical model. Science 189 58-60, 1975... 

Receptor-Binding Studies. Quetiapine (Seroquel) is also a dibenzothiazepine derivative produced by altering the structure of clozapine. This agent has an affinity for multiple brain receptors, a low propensity to evoke EPS in preclinical tests considered predictive of antipsychotic activity, and does not produce sustained plasma prolactin levels. 

Amoxapine has been found to be effective in several double-blind studies (Table 7-4 and Table 7-6). It is a dibenzoxazepine derivative that has both NE and serotonin uptake inhibiting properties. Amoxapine is converted into 8-hydroxyamoxapine, which has considerable dopamine receptor binding properties (i.e., radioreceptor bioassays on patients given amoxapine have found activity levels similar to those of patients on typical antipsychotics), a chemical structure similar to loxapine, and effects similar to antipsychotics (1Q3). As a result of this metabolite, amoxapine theoretically may have unique beneficial effects in psychotically depressed patients. However, this possibility has never been adequately tested. Nevertheless, this metabolite is likely responsible for some of the antidopamine effects reported in patients taking amoxapine, including acute and chronic extrapyramidal side effects and elevated prolactin levels ( 104). Like TCAs, amoxapine can be lethal in... 

Growth hormone is a 191-amino-acid peptide with two sulfhydryl bridges. Its structure closely resembles that of prolactin. In the past, medicinal GH was isolated from the pituitaries of human cadavers. However, this form of GH was found to be contaminated with prions that could cause Creutzfeldt-Jakob disease. For this reason, it is no longer used. Somatropin, the recombinant form of GH, has a 191-amino acid sequence that is identical with the predominant native form of human GH. 

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