Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

High concentrations of Thyrotrophin-Releasing Hormone (TRH) have been found in the dorsal skin of the Frog Rana esculenta, lower levels being measured in the ventral skin. alpha-MSH and somatostatin were undetectable in these tissues. Nor was TRH detected in the blood of these animals. The concentration of somatostatin in the pancreas was similar to that of the hypothalamus and twice or one hundred times higher than in the intestine or stomach respectively.
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PMID:[Distribution of thyrotropin releasing hormone (TRH), alpha-melanocyte-stimulating hormone (alpha-MSH) and somatostatin in the skin of the green frog (Rana esculenta)]. 11 17

The regional and subcellular distribution of immunoreactive alpha-melanocyte stimulating hormone (alpha-MSHi) in the post mortem adult human brain was investigated. alpha-MSHi was highly concentrated in medial basal hypothalamic tissue (1.02 ng/mg protein). Lower levels of alpha-MSHi were present in the optic chiasm and mammillary bodies, 0.08 and 0.11 ng/mg protein, respectively. The concentrations of alpha-MSHi in cerebellum and frontal cerebral cortex were 1/1,000th that of the medial basal hypothalamus. When medial basal hypothalamic homogenates were subjected to discontinuous or continuous sucrose density gradients, alpha-MSHi was found to be associated primarily with subcellular particles which resembled isolated nerve terminals, i.e., synaptosomes. Low to undetectable amounts of alpha-MSHi were found in the cytosol or the myelin/microsome fraction of the gradients. The results of these studies are consistent with the view that alpha-MSH is a neuronal peptide in the human brain.
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PMID:Subcellular localization of immunoreactive alpha-melanocyte stimulating hormone in human brain. 11 78

We have compared the capacity to secrete ACTH in response to stress or adrenalectomy in control rats and in those with total hypophysectomy (H), adenohypophysectomy (AH) with preservation of the intermediate and the neural lobes, neurohypophysectomy (NH) with removal of the pars nervosa and all or part of the pars intermedia with preservation of the adenohypophysis, or incomplete adenohypophysectomy (IAH) in which a portion of the adenohypophysis and all of the pars intermedia and pars nervosa were left intact. Plasma ACTH measured with an N-terminal antibody that reacts on an equimolar basis with ACTH and alpha-MSH but not with other known pituitary hormones was elevated after ether or tourniquet stress in all except the H group. Three weeks after adrenalectomy there was an elevated basal plasma ACTH and an augmented ACTH response to stress in intact and IAH but not in AH rats. When a more specific alpha11-24 ACTH antibody was used there was a high plasma ACTH after ether stress in the IAH, NH, and intact groups but not in the AH or H groups. Adrenal weight and plasma corticosterone after tourniquet or ether stress were indistinguishable in the AH and H groups and were much higher and nearly identical in the intact, NH and IAH groups. We conclude that only the adenohypophysis secretes functionally significant amounts of ACTH. Plasma ACTH detected by the N-terminal antibody in the AH group is probably related to alpha-MSH or similar peptides and is incapable of maintaining adrenal weight or stimulating corticosterone secretion.
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PMID:Evidence that the pars intermedia and pars nervosa of the pituitary do not secrete functionally significant quantities of ACTH. 16 33

The effect of synthetic alpha-MSH injected intravenously in a uniform dose of 3 mg was studied in 19 prepubertal children. A marked growth hormone (GH) response was seen only in 2 out of 8 constitutionally small children with a normal GH response to insulin and arginine stimulation. Three of of 11 children suffering from hypopituitarism with documented GH and other hormone deficiencies, unexpectedly, showed a significant rise of GH after alpha-MSH: all three had craniopharyngiomas. Alpha-MSH led to an increase of plasma cortisol in all except 3 patients who had secondary adrenal insuffciency. The increase of cortisol after alpha-MSH and after insulin was of the same extent: but the hypoglycemia and stress responsible for the insulin effect were not observed after alpha-MSH. It is possible that alpha-MSH acts by an ACTH-like direct stimulation on the adrenals. There was no effect of alpha-MSH on plasma TSH or on blood glucose.
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PMID:The effect of alpha-MSH on plasma growth hormone, cortisol and TSH in children. 16 18

A sensitive bioassay for the measurement of plasma ACTH is presented. The use of silicic acid adsorption of plasma, with a subsequent acid wash and aqueous acetone desorption, was successful in removing those substances which had interfered with the steroidogenic response of dispersed adrenal cells when unextracted plasma was employed. This extraction procedure extracted 72-76% of ACTH present in plasma. Two pg ACTH1-39 could be consistently detected. Alpha-hACTH1-39 and alpha-pACTH1-39 exhibited equal potencies. Beta-MSH was ineffective at dosage levels up to 2 x 10(8) pg. One x 10(8) pg of ACTH1-10, ACTH4-10, or alpha-MSH had a steroidogenic effect equivalent to that of 40 pg ACTH1-39. ACTH 17-39 and ACTH 11-24 were incapable of stimulating steroid production at doses of 1 x 10(8) pg. Excesses of the latter, but not of the former appeared to be able to antagonize the steroidogenic effect of ACTH1-39. Plasma from normal subjects, bioassayed by this extraction procedure, contained 12-186 pg/ml ACTH at 0400-0800: 14-93 pg/ml ACTH at 1000-1300, and less than 10-34 pg/ml ACTH at 1600-2200. Hypoglycemia and vasopressin administration were followed by increases in plasma ACTH concentratrations. Plasma ACTH concentrations in untreated patients with Cushing's disease (sampled over the period 0900-1300) ranged from 65-220 pg/ml. Three patients with Addison's disease (untreated or 12 h following replacement steroid withdrawal) had ACTH concentrations of 223, 370 and 1226 pg/ml. Markedly elevated ACTH concentrations were observed in a patient with Nelson's syndrome (391 and 835 pg/ml). Bioassayable ACTH was not detected in 2 patients with panhypopituitarism.
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PMID:A sensitive bioassay for the determination of human plasma ACTH levels. 16 19

Pituitary sections from 15 to 21 day-old rat foetuses have been studied with the immunofluorescence technique, using antibodies anti alpha-MSH, anti beta-MSH and anti beta (1-24) ACTH. The first ACTH cells appear on day 17 of pregnancy in the pars distalis of the hypophysis and only on day 18 in the pars intermedia. beta-msh cells have been observed on day 16 in the pars anterior and on day 17 in the pars intermedia, while alpha-MSH cells appear only on day 18 and exclusively in the pars intermedia. The cytodifferentiation of the beta-MSH and ACTH cells occurs in the pars intermedia with about a 24 hours delay in comparison to that of the pars distalis. The first revealed cells are always located in the posterior half of the pituitary gland. The corticostimulating activity of the hypophysis has been tested with the fluorescence intensity of the corticotrophs, the adrenal weight, the adrenal content in corticosterone and the plasma corticosterone level. The fluorescence of the corticotrophs increases on day 18, shows a maximum on day 19 and decreases until term. The adrenal weight rises regularly between day 16 to day 20, thereafer the increase subsides. Adrenal and plasma corticosterone concentrations reach a peak on day 19 of pregnancy. These data suggest that hypophyseal corticostimulating activity is very high between days 18 and 19 and decreases between days 19 and 21.
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PMID:Ontogenesis of the alpha-MSH, beta-MSH and ACTH cells in the foetal hypophysis of the rat. Correlation with the growth of the adrenals and adrenocortical activity. 16 96

A simple and rapid assay for the quantitative determination of melanocyte-stimulating hormone (MSH) activity, using skin fragments of the lizard Anolis carolinensis in vitro, is described in detail. This assay, in which a quantal response (e.g. induction of a brownish-green colour) can be detected by visual observation, allows determination of MSH activity in up to 50 samples/day by one person, using the skin of one lizard. The mean dose found to induce this colour change was 0-15 ng synthetic alpha-MSH/ml (range 0-02-0-5 ng/ml). The assays shows high accuracy, reproducibility and specificity. Anterior and posterior lobe hormones as well as pituitary catecholamines do not interfere with the determination of pituitary MSH activitymthe method is compared with the assay using hypophysectomized frogs (Rana pipiens) in vivo. Determinations of MSH in pituitary extracts by both methods gave quantitatively similar results when determined with alpha-MSH as the reference substance. However, when beta-seryl MSH was used as a reference, the two assays gave different results for the MSH activity of the pituitary extractsmthis indicates that MSH from the rat pituitary gland has a biological activity similar to that of alpha-MSH rather than to that of beta-seryl MSH.
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PMID:Re-introduction and evaluation of an accurate, high capacity bioassay for melanocyte-stimulating hormone using the skin of Anolis carolinensis in vitro. 17 Mar 54

Alpha-MSH, beta-MSH and ACTH have been localized in the cells of hypophyseal intermediate lobe by fluorescence histoimmunological technics. Elaboration and excretion of these polypeptides are enhanced after dehydration or adrenalectomy. The most evident variations are seen with alpha-MSH and ACTH after dehydration, with beta-MSH after adrenalectomy.
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PMID:Immunohistochemical study of the pars intermediate of the mouse pituitary in different experimental conditions. 17 45

To investigate whether the hypothalamus is involved in the cytodifferentiation of the anterior pituitary gland, rat foetuses were encephalectomized in utero on day 16 of pregnancy. Pituitary sections from encephalectomized and normal littermate foetuses were studied on day 21 with the immunofluorescence technique using antibodies anti alpha-MSH, anti beta-MSH, anti alpha-(17-39) ACTH and anti beta-(1-24) ACTH. On day 16, only the anti beta-MSH revealed a few cells in the pars distalis but not in the pars intermedia. On the other hand, on day 21, the pituitary cells reacting with antibodies anti alpha-MSH, anti beta-MSH and anti alpha-(17-39) ACTH were as numerous in the encephalectomized foetuses as in the normal littermate foetuses. The cells revealed with the antibody anti beta-(1-24) ACTH were less numerous and less fluorescent in the pars distalis and intermedia of the hypophysis of the encephalectomized foetuses. On day 21, the adrenals of the encephalectomized foetuses were atrophied in comparison with those of the normal littermate foetuses but they were larger than on day 16. These data suggest that the cytodifferentiation of the corticotroph and melanotroph cells of the hypophysis occurs without the influence of the hypothalamus which is necessary for the normal release of ACTH.
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PMID:Hypothalamus and cytodifferentiation of the foetal pituitary gland. Study in vivo. 18 Nov 34

It is proposed that all peptide hormones and releasing factors are biosynthesized in the form of precursor molecules which are biologically inactive. Enzymic activation may take place by hydrolytic cleavage to release a terminal COOH group or by transmidation to form a COOH-terminal amide. Studies with pituitary prohormones and hormones are providing data that support this hypothesis. Evidence has been obtained that the 91 residue beta-lipotropin (beta-LPH) is the prohormone of beta-melanotropin (beta-MSH). The specificity of the pituitary enzymes involved in release of the hormone was demonstrated by the isolation of five constituent fragments of LPH, which were obtained in homogeneous form from the pituitary gland of the pig. The enzymes have specificities similar to trypsin and carboxypeptidase B; carboxypeptidase A and aminopeptidase activities do not appear to be involved. Mild digestion of beta-LPH by trypsin in vitro has confirmed the susceptibility of the peptide bond on the carboxy side of the paired basic residues at positions 59 and 60, adjacent to the COOH-terminus of beta-MSH, and tryptic digestion of a model peptide demonstrated the same specificity. The paired basic residues at positions 39 and 40 adjacent to the NH2-terminus of beta-MSH were more resistant to tryptic attack, both in LPH and in a model peptide. In the gland it is apparent that LPH is cleaved on the carboxy side of the paired lysyl residues at positions 39 and 40, whereas in the synthetic peptide cleavage takes place in between these residues. The activating enzyme may differ from trypsin; alternatively, explanation may be found in the conformation of the prohormone. Prediction of secondary indicates that both pairs of basic residues lie adjacent to beta-bends on the surface of the molecule and occupy sites accessible to enzymic attack. It seems likely that alpha-MSH and corticotropin (ACTH) share a common pro hormone. The release of ACTH could involve cleavage of a -Gly-Ser- bond in the prohormone to expose the NH2-terminus of the hormone. With alpha-MSH, a concerted acetylation and cleavage may take place to form the N-acetylserine residue; the COOH-terminus may be released as an amide by direct transamidation of a -Val-Gly- bond in the prohormone. Release of either hormone would be accompanied by the release of contiguous fragments of the prohormone. We have isolated two novel polypeptides from pig pituitary in substantial quantity and have determined the primary structures. They may represent fragments of a prohormone to alpha-MSH or ACTH.
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PMID:Prohormones of beta-melanotropin (beta-melanocyte-stimulating hormone, beta-MSH) and corticotropin (adrenocorticotropic hormone, ACTH): structure and activation. 18 Dec 27


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