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)

Schistosomes are digenetic trematodes which share their life cycle between a definitive (vertebrate) and an intermediate (invertebrate) host. Their survival is highly dependent on their ability to reduce significantly the efficiency of the host defences. We have previously demonstrated the presence of POMC derived peptides (ACTH, alpha-MSH, beta-endorphin) in all stages of Schistosoma mansoni life cycle. Given the immunomodulatory properties of these peptides in vertebrates and invertebrates it has been postulated that they might be implicated in parasite immune evasion. We report the release of these neuropeptides during the cycle, associated with the inhibition by these peptides of the locomotory activity of immunocytes from both hosts, the hamster Mesocricetus auratus and the freshwater snail B. glabrata. The implication of these common signals in this new strategy of parasite adaptation is discussed.
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PMID:Proopiomelanocortin-derived peptides as tools of immune evasion for the human trematode Schistosoma mansoni. 129 18

Intracerebroventricular (icv) infusion of human interleukin 1 beta (IL-1) into intact and adrenalectomized rats impairs immune function. Using antibody to IL-1 as well as an inhibitor of IL-1 action, we sought to determine if endogenous IL-1 in the central nervous system has a physiological role in mediating the immunosuppressive effects of stress. Compared with freely moving controls, rats given intermittent electric shock to the tail for 40 min exhibited a fall in T lymphocyte proliferation and natural killer (NK) cell cytotoxicity of 33% and 38%, respectively; however, when pretreated with icv human IL-1 monoclonal antibody, which significantly crossreacts with rat IL-1, the decrement was attenuated to 14.6% and 15%, respectively. When rats were pretreated with icv alpha-MSH, which blocks many IL-1 effects, shock-induced suppression of 42% in both T lymphocyte proliferation and NK cytotoxicity were blunted to 33% and 31%, respectively. Similar results were found in adrenalectomized rats. These findings suggest that endogenous IL-1 is a physiologically relevant mediator of the immune response to stress. As IL-1 has been reported to release CRF, which we have shown always plays a significant role in stress-induced immunomodulation, we then assessed the relationship of IL-1 and CRF in immunosuppression. Infusion of icv IL-1 caused a decrease of 35% in T lymphocyte proliferation and 34% in NK activity, but pretreatment with CRF antibody icv attenuated IL-1 suppression of T lymphocyte proliferation and NK activity to 10% and 8%, respectively. Comparable results were observed in adrenalectomized rats. These findings suggest that CRF antibody is able to block the immunosuppressive effects of IL-1. To further examine the interaction of CRF in mediating stress-induced immunosuppression, we found that animals pretreated with icv CRF antibody, shocked and then given icv IL-1, had a decrement in T lymphocyte proliferation and NK cytotoxicity of 24% and 21%, respectively, demonstrating that the immunosuppressive effect of icv IL-1 is blocked when central CRF has been neutralized by prior administration of icv CRF antibody. In contrast, animals pretreated with icv IL-1 antibody, shocked and then given icv CRF, had decrements of 38% and 40%, respectively, showing that icv CRF does act even when central IL-1 has been neutralized by prior administration of icv IL-1 antibody. Thus, we conclude there is a sequential relationship between two of the known mediators of stress-induced immunosuppression, with release of central IL-1 followed by that of CRF.
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PMID:Interleukin 1 beta mediates stress-induced immunosuppression via corticotropin-releasing factor. 130 24

The combined effects of ACTH, beta-endorphin (beta-EP) and alpha-MSH were studied on the corticosteroidogenesis of isolated rat adrenocortical zona fasciculata and zona glomerulosa cells. beta-EP potentiated the effects of ACTH and alpha-MSH on the zona fasciculata corticosterone production but inhibited those on the zona glomerulosa aldosterone production. beta-EP did not affect the combined action of 4 x 10(-11) M ACTH and 5 x 10(-9) M alpha-MSH on the zona fasciculata or the zona glomerulosa cells, but it inhibited the stimulatory action of the combination of 1.6 x 10(-10) M ACTH and 10(-9) M alpha-MSH on the zona glomerulosa aldosterone production. An interaction of ACTH, beta-EP and alpha-MSH in relation to the zona fasciculata and zona glomerulosa corticosteroid production was found.
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PMID:Interaction of ACTH, beta-endorphin and alpha-melanocyte stimulating hormone in relation to the corticosteroid production of isolated rat adrenocortical zona fasciculata and zona glomerulosa cells. 130 7

Evidence supporting the concept that the parasitic trematode Schistosoma mansoni may escape immune reactions from its vertebrate (man) or invertebrate (the freshwater snail Biomphalaria glabrata) hosts by using signal molecules it has in common with these hosts was obtained by the following experiments. The presence of immunoactive proopiomelanocortin (POMC)-derived peptides [corticotropin (ACTH), beta-endorphin] in, and their release from, S. mansoni was demonstrated. Coincubation of adult worms with human polymorphonuclear leukocytes or B. glabrata immunocytes led to the appearance of alpha-melanotropin (MSH) in the medium. The conclusion that this alpha-MSH resulted from conversion of the parasite ACTH by neutral endopeptidase 24.11 (NEP) present on these cells was supported by the fact that the alpha-MSH level in the medium was markedly reduced by addition of the specific NEP inhibitor phosphoramidon. This interpretation is substantiated by the fact that no conversion was observed in comparable tests with human monocytes, which exhibit no NEP activity. alpha-MSH has the capacity to inactivate formerly active immunocytes not only from the definitive host (man, hamster) but also from the intermediate host (B. glabrata), as determined by microscopic computer-assisted examination of conformational changes. POMC-derived peptides have been detected in B. glabrata hemolymph 2, 10, and 24 days after infection by S. mansoni miracidia. Immunocytes from infected snails were found to be inactivated, and this inactivation was prevented by antibodies directed against ACTH and alpha-MSH. The immunoactive beta-endorphin released from S. mansoni does not appear to be subject to enzymatic conversion. Since it is active at lower concentrations, it may be used for distant signaling.
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PMID:Immunosuppression in the definitive and intermediate hosts of the human parasite Schistosoma mansoni by release of immunoactive neuropeptides. 130 57

A case is presented of generalized skin hyperpigmentation due to alpha-MSH hypersecretion from the pituitary that was most marked in the light-exposed areas. The patient also had secondary adrenal dysfunction, peripheral lymphadenopathy, streptococcal glomerulonephritis and malabsorption. Analysis of this patient's alpha-MSH using high-pressure liquid chromatography (HPLC) showed a novel acetylation profile compared to normal individuals and to patients with Cushing's disease and Nelson's syndrome. Glucocorticoid replacement therapy resulted in suppression of alpha-MSH hypersecretion and complete resolution of the illness.
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PMID:A case of skin hyperpigmentation due to alpha-MSH hypersecretion. 131 79

Two patients with AIDS are described who developed acral hyperpigmented macules of the fingers, palms and soles, buccal mucosa and genitalia, associated with longitudinal melanonychia. These pigmentary changes seemed to be independent of zidovudine and were associated in one with diffuse melanoderma and elevated levels of alpha-MSH. Histological and ultrastructural studies showed an increase of the dendrites and pigmentation of the melanocytes and few melanosomes in the keratinocytes.
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PMID:Acral hyperpigmented macules and longitudinal melanonychia in AIDS patients. 131 50

The present study was aimed at investigating whether PACAP stimulates accumulation of cAMP, as well as hormonal secretion of homogeneous populations of pituitary proopiomelanocortin (POMC) cells, namely melanotrophs and AtT-20 corticotrophs. PACAP was shown to enhance cAMP accumulation in a dose-dependent fashion in both cell types (with EC50 values of approx. 10(-10) M) and elicited additive increases of cAMP production with CRF in melanotrophs, but not in corticotrophs. PACAP also stimulated dose-dependently the secretion of alpha-MSH and ACTH, with EC50 concentrations of about 10(-9) M. In melanotrophs, bromocriptine significantly depressed PACAP-induced cAMP formation and blunted by more than 90% stimulated alpha-MSH release. This study shows that (1) pituitary POMC cells did respond to PACAP by enhancing cAMP accumulation and elevating hormone secretion as well; (2) the effect of PACAP was additive with CRF on cAMP production in melanotrophs, but not in corticotrophs, while there was no additivity on peptide output from both cell types; (3) activation of dopamine receptors in melanotrophs dampened both cAMP formation and peptide secretion. These findings are consistent with PACAP playing a possible hypophysiotropic role in the regulation of pituitary POMC cell activity.
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PMID:Pituitary adenylate cyclase-activating polypeptide (PACAP) stimulates cyclic AMP formation as well as peptide output of cultured pituitary melanotrophs and AtT-20 corticotrophs. 131 48

An attempt was made to culture neural crest cells of the turtle embryo in vitro. Trunk neural tubes from the St. 9/10 embryos were explanted in culture dishes. The developmental potency of the turtle neural crest cells in vitro was shown to be essentially similar to that of avian neural crest cells, although they seem to be more sensitive to melanocyte-stimulating hormone (MSH) stimulation. We describe conditions under which explanted neural tube gives rise to neural crest cells that differentiate into neuronal cells and melanocytes. The potency of melanocyte differentiation was found to vary according to the concentration of fetal bovine serum (FBS, from 5 to 20%). Melanization of neural crest cells cultured in the medium containing FBS and alpha-MSH was more extensive than those cultured with FBS alone, combinations of FBS and chick embryo extract, or turtle embryo extract. These culture conditions seem to be useful for the study of the developmental potency of the neural crest cells as well as for investigating local environmental factors.
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PMID:Differentiation of reptilian neural crest cells in vitro. 131 37

The antipyretic effect of AVP, alpha-MSH and ACTH consists in lowering the thermoregulatory threshold and in shortening the time span of the fever. Thus, neuropeptides influence activity of hypothalamic neurones regulating body temperature. This was confirmed by recent experiments of Moravec (this volume) which indicate that spontaneous activity and thermosensitivity of neurones in hypothalamic slices can be influenced, by AVP. Why neuropeptides of different chemical structure such as AVT, on one hand, and alpha-MSH and ACTH, on the other hand, induce the same effect on thermoregulation remains to be elucidated.
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PMID:A discrete mode of the antipyretic action of AVP, alpha-MSH and ACTH. 131 96

Male Wistar rats living in colonies of 4 males plus 4 females were compared to noncolony males, cohabitating with a female. Irreversible dominance relationships developed between one dominant male (D) and three subordinates (S). Dominants developed high basal testosterone levels and large preputial glands. Subordinates had reduced preputial glands despite normal testicle weights and normal basal testosterone levels. Basal corticosterone was elevated in both ranks, in S more so than in D, while in acute encounters both ranks showed a similar increase in the corticosterone-to-ACTH ratio. They also underwent a similar reduction in thymus weight, while an increase in adrenal weight was more pronounced in D. In D-S-I encounters, during which D simultaneously attacked S and an intruder (I) for 20 minutes, both defenders showed a 3-4 fold increase in plasma prolactin, while in the offensive dominant the level remained low. Similar, but weaker hormonal contrasts between offence and defence were found for beta-endorphin, ACTH, and corticosterone, while alpha-MSH and testosterone did not discriminate. In our view, the marked hyporesponsiveness of prolactin to acute offence may be associated with a specific offensive setting of dopaminergic inhibitory and beta-adrenergic stimulatory influences.
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PMID:Hormonal reactions to fighting in rat colonies: prolactin rises during defence, not during offence. 131 90


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