Disease relevance of beta-MSH

• Ectopic production of antidiuretic hormone (adh), adrenocorticotrophic hormone (ACTH) and beta-melanocyte stimulating hormone (beta-MSH) by an oat cell carcinoma of the lung [1].
• Immunoreactive ADH, ACTH and beta-MSH were detected in the primary tumor and in metastases to the liver. beta-MSH was also detected in the spleen, in which metastases were observed [1].
• The effect of synthetic MIF (H-Pro-Leu-Gly-NH2) on beta-MSH secretion was studied in five patients with Nelson's syndrome and in one patient with Addison's disease [2].
• Binding of beta-melanotropin (beta-MSH) and subsequent activation of adenylate cyclase in the M2R mouse melanoma cell line is strongly dependent on the concentration of extracellular free calcium [3].
• During insulin-induced hypoglycemia, there was a marked increase of plasma ACTH levels and a slight but significant increase of plasma beta-MSH levels [4].

Psychiatry related information on beta-MSH

• Withdrawal symptoms in morphine-dependent rats intracerebroventricularly injected with ACTH1-24 and with beta-MSH [5].
• In addition, males showed a strong feeding response to intermedine/lycopsamine, whereas the other PAs elicited no positive feeding behavior [6].

High impact information on beta-MSH

• It is well established that the melanotropins alpha- and beta-MSH are responsible for pigment dispersion in the integumentary melanophore of lower vertebrates and that these molecules are derived from a common precursor protein, proopiocortin, by specific processing within the intermediate lobe [7].
• As the amino acid sequence of beta-MSH is contained within the beta-LPH structure, we have now investigated the aldosterone-stimulating activity of synthetic beta-MSH [8].
• Earlier studies have suggested that beta-melanotrophin (beta-MSH) has only weak steroidogenic potency on the adrenal gland in the rat, but recently Challis et al.5 and Rudman et al.6 have reported that alpha- and beta-MSH have a trophic action on fetal adrenal gland [8].
• We have now isolated from a rat genomic DNA library a segment of a DNA encoding most of POMC, using as probe a mouse 144-base pair cloned cDNA fragment encoding beta-MSH and beta-endorphin [9].
• Beta-TC3 cells transfected with the mutant POMC cDNA produced a mutant beta-MSH/beta-endorphin fusion protein [10].

Chemical compound and disease context of beta-MSH

• In this study, two melanotropin binding proteins from M2R melanoma cells have been identified based on the photochemical cross-linking of [125I]iodinated porcine beta-MSH ([ 125I]iodo-beta-MSH) to melanoma cell membranes, using N-hydroxysuccinimidyl-azidobenzoate [11].
• Phenothiazine therapy and plasma immunoreactive beta-MSH in schizophrenia and pruritic dermatoses [12].
• We have found that preparations of rate-zonal purified Moloney murine leukemia virus originally obtained from the National Cancer Institute Resources Program, when separated by SDS-PAGE in the absence of mercaptoethanol (beta-MSH), exhibited a doublet envelope glycoprotein band of approximately 69/67 kD [13].

Biological context of beta-MSH

• The corresponding amino acid sequence translated from this mRNA revealed in the cryptic region of the precursor protein a fragment sharing a common amino acid sequence with the alpha- beta-melanotropins (alpha-MSH, beta-MSH) and thus named gamma-MSH [14].
• Two children were found to be heterozygous for a missense mutation, R236G, which disrupts the dibasic cleavage site between beta melanocyte-stimulating hormone (beta-MSH) and beta-endorphin [10].
• The nucleotide sequence of a 1050-base pair hybridization-positive cDNA clone was determined and the deduced amino acid sequence of Xenopus POMC revealed the sequences of Xenopus gamma-MSH, alpha-MSH, corticotropin-like intermediate lobe peptide, beta-MSH, and beta-endorphin [15].
• At a final dilution of 1:24,000, the antiserum employed shows cross-reaction with beta hLPH but none with human beta-MSH (beta hMSH), and it is concluded that the antigenic determinant lies within the N-terminal 1-36 region of beta hLPH [16].
• Diurnal rhythm and disappearance half-time of endogenous plasma immunoreactive beta-MSH (LPH) and ACTH in man [17].

Anatomical context of beta-MSH

• Adrenocorticotropin, a precursor of alpha-MSH, but not the structurally unrelated beta-MSH, competitively inhibited alpha-MSH binding, suggesting that the receptor expressed on monocytes is specific for alpha-MSH [18].
• Whole pituitary glands obtained from Day 50 and 55 fetal monkeys and separated lobes From Day 65 to 155 were extracted, fractionated, and analyzed for beta-melanotropin (beta-MSH), midportion beta-endorphin (beta-EP), and acetylated beta-EP immunoactivity [19].
• Secretion of tumor ACTH was significantly stimulated in all cases by crude rat median eminence extract which was also effective in stimulating beta-MSH secretion associated with elevated tissue cyclic AMP levels in one [20].
• Our results suggest that alpha-MSH, ACTH, and possibly beta-MSH, but not gamma-MSH, are capable of a physiological role in regulating human pigmentation, and that melanocytes in human skin are a specific target for these hormones [21].
• No significant binding to human fibroblast and human carcinoma cells was seen. alpha-MSH, beta-MSH and, to a lesser extent ACTH4-10 (a part of the alpha-MSH sequence) were the only peptides able to displace labelled alpha-MSH from its binding sites, indicating the high specificity of the MSH receptor [22].

Associations of beta-MSH with other chemical compounds

• This suggests that the control of beta-MSH secretion in man, unlike that of prolactin in man and MSH peptides in other mammals, is not predominantly inhibitory [23].
• The effect of chlorpromazine on the secretion of immunoreactive beta-MSH and prolactin in man [23].
• In the same patients, LVP stimulation and dexamethasone suppression tests brought about significant changes in the plasma beta-MSH and ACTH levels [2].
• Hydrolysis, followed by oxidation, led to the N-oxides of indicine, intermedine, lycopsamine, and the new nonnatural product, respectively [24].
• Synthetic alpha-MSH was compared to beta-MSH, ACTH1-24, ACTH4-10, beta-LPH, CLIP, CRF, MIF I, A8VP and beta-endorphin [22].

Gene context of beta-MSH

• Structure-activity relationships of novel cyclic alpha-MSH/beta-MSH hybrid analogues that lead to potent and selective ligands for the human MC3R and human MC5R [25].
• When the MC-2 DNA is expressed in COS-7 cells, it binds [125I]-labelled [Nle4, D-Phe7]- alpha melanocyte stimulating hormone (NDP-MSH) which then could be displaced by melanotropic peptides alpha-MSH, beta-MSH, gamma-MSH and adrenocorticotropic hormone, but not by non-melanotropic peptide beta-endorphin [26].
• Compared to wild-type beta-MSH, the variant peptide was impaired in its ability to bind to and activate signaling from the MC4R [27].
• Consequently, the autocrine synthesis and release of the key hormones ACTH, alpha and beta-MSH and beta-endorphin takes also place in melanocytes [28].
• To further analyze how melanotropins produce these biological effects, we investigated the regulation of the melanocortin receptor MC1R expression by alpha-MSH and ACTH using Northern blot analysis and determine the relative affinity of the receptor for the structurally similar peptides alpha-MSH, ACTH, beta-MSH, and gamma-MSH [21].

Analytical, diagnostic and therapeutic context of beta-MSH

• Immunocytochemical study by means of the immunoperoxidase technique and light or electron microscopy demonstrated 1-24/1-39 adrenocorticotropic hormone (ACTH) in all cases, lipotropin/melanotropin (beta-LPH/beta-MSH) in 10 cases, beta-endorphin in 8 cases, and an absence of calcitonin in all cases [29].
• Simultaneous measurements of both beta-melanocyte stimulating hormone (beta-MSH) and adrenocorticotropic hormone (ACTH) in extracted plasma were performed by specific radioimmunoassays [4].
• We studied the plasma immunoreactive beta-MSH ("beta-MSH") in hemodialysis patients to determine its basal level, plasma disappearance rate, gel filtration and immunological characteristics [30].
• A human pituitary adenoma responsible for a case of Nelson's syndrome was maintained in organ culture and the incubation medium was examined with four different RIAs; human corticotropin (ACTH), beta-MSH, lipotropin (LPH), and beta-endorphin (beta-End) [31].
• Two-dimensional (2D) SDS-PAGE where the first dimension was run under nonreducing conditions and the second with beta-MSH, supported the contention that the 130K band was a dimeric complex of Pr65gag [32].

References