Specific binding of 2-[125I]iodomelatonin by rat splenocytes: characterization and its role on regulation of cyclic AMP production

Rafii-El-Idrissi, Mohammed; Calvo, Juan R.; Pozo, David; Harmouch, Ahmed; Guerrero, Juan M.

doi:10.1016/0165-5728(94)00182-n

Cited by 66 publications

(21 citation statements)

References 28 publications

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“…Similar results have been observed in rat spleen cells, where the K d value of melatonin binding appears in the nanomolar range [60]. A saturable and concentration-dependent binding of 2[ 125 I]melatonin was found in rat thymus membranes, characterized by a linear Scatchard plot, suggesting the binding to a single class of binding sites [58,61].…”

Section: Melatonin Mechanism Of Actionsupporting

confidence: 64%

Melatonin Involvement in Immunity and Cancer

Fraschini¹,

Demartini²,

Esposti³

et al. 1998

Neurosignals

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The most studied endocrine product of the pineal gland, melatonin, has been reported to be involved in the feedback between neuroendocrine and immune functions and to exert oncostatic action, at least in certain experimental conditions. Melatonin seems to be an integral part of the immune system, by exerting direct and/or indirect stimulatory effects on both cellular and humoral immunity. Likewise, an antitumor activity of melatonin has been shown in several experimental models in vivo and in vitro. The means by which melatonin exerts its effects on immunity and neoplastic growth have not been elucidated. The different putative mechanisms of action of melatonin investigated so far are here briefly discussed.

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Section: Melatonin Mechanism Of Actionsupporting

confidence: 64%

Melatonin Involvement in Immunity and Cancer

Fraschini¹,

Demartini²,

Esposti³

et al. 1998

Neurosignals

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“…The immunoenhancing and antistress properties of melatonin are closely related effects, and both of these effects may be blocked by administration of the opioid antagonists naloxone or naltrexone, whereas dynorphin and β-endorphin reproduce the immunological effects of melatonin [23]. A direct effect of melatonin on the immune system was further demonstrated in several experimental paradigms [40, 41]. Th1 and Th2 lymphocytes are targets for melatonin action [25, 28, 40], and the indoleamine enhances the release of Th1 cytokines, such as IFN-γ and IL-2 as well as of novel opioid cytokines which cross-react immunologically with both IL-4 and dynorphin B.…”

Section: Discussionmentioning

confidence: 99%

Melatonin and β-Endorphin Changes in Children Sensitized to Olive and Grass Pollen after Treatment with Specific Immunotherapy

Girón-Caro

Muñóz-Hoyos²,

Ruiz-Cosano³

et al. 2001

Int Arch Allergy Immunol

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Background: Specific immunotherapy for respiratory allergy, a seasonal disease, significantly reduces the inflammatory process, attenuating the clinical symptoms. The mechanism for the clinical beneficial effect of immunotherapy has not yet been clarified. Melatonin shows a circadian and seasonal variation and together with the endogenous opioid system plays an immunomodulatory role acting on both specific and nonspecific immunity responses. Thus, the possibility that immunotherapy involved changes in the melatonin-opioid system was investigated. Methods: Thirty-five children aged 3–15 years with rhinitis and asthma due to olive + grass pollen sensitization were studied. The patients were treated with depot extracts containing the identified allergens with increasing doses from 1 to 1,000 IU/ml during 3 months. Melatonin, β-endorphin, total and specific IgE and IgG4 were determined before and after treatment. Results: All children showed a significant improvement of their symptoms at the end of the treatment, coinciding with a significant drop of both melatonin and β-endorphin levels. Total IgE decreased in most of the cases although the mean values did not show significant changes. Specific IgE and IgG4 were also unchanged. A significant correlation between melatonin and β-endorphin and between β-endorphin and IgG4 was found before immunotherapy, and these correlations disappeared when the treatment was finished. Conclusions: The decrease in the levels of melatonin and β-endorphin suggests the disappearance of their stimulating influence on the immune system. Thus, hyposensitization after immunotherapy may involve, at least in part, the inhibition of the immunoenhancing properties of the melatonin-opioid system.

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“…High affinity melatonin receptors have been localized on circulating lymphocytes from rodents, chickens, and humans [16, 17], and on thymocytes and splenocytes in humans and several rodent and bird species [18, 19, 20]. In vitro melatonin administration enhances the proliferative ability of splenocytes from both female and male prairie voles (Microtus ochogaster) [21, 22], and enhances the mitogenic response of peripheral blood T lymphocytes from chickens [23].…”

Section: Introductionmentioning

confidence: 99%

Melatonin Receptor Subtype MT2 (Mel 1b) and Not mt1 (Mel 1a) Is Associated with Melatonin-Induced Enhancement of Cell-Mediated and Humoral Immunity

Drazen

Nelson²

2001

Neuroendocrinology

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Individuals of many vertebrate species undergo seasonal changes in immune function in addition to marked seasonal changes in reproductive, metabolic, and other physiological processes. Despite growing evidence that photoperiod mediates seasonal changes in immunity, little is known regarding the neuroendocrine mechanisms underlying these changes. Enhanced immune function in short days is correlated with increased duration of nightly melatonin secretion, and recent studies indicate that melatonin can act directly on immune cells to enhance immune function. It remains unknown, however, which melatonin receptor subtype mediates immune enhancement by melatonin. The present study examined the contribution of specific melatonin receptor subtypes, mt1 (Mel 1a) and MT2 (Mel 1b), in mediating melatonin-induced enhancement of cell-mediated and humoral immune function in mice. Melatonin enhanced both splenocyte proliferation and anti-keyhole limpet hemocyanin (KLH) IgG concentrations in both wild-type (WT) and mice lacking a functional gene for melatonin receptor mt1 (mt1 –/–), suggesting that the mt1 receptor does not mediate these responses. In addition, luzindole, an MT2 receptor antagonist, attenuated melatonin-induced enhancement of splenocyte proliferation in both WT and mt1 –/– mice. Taken together, these results suggest that receptor subtype mt1 is not necessary for mediating melatonin-induced enhancement of immune function and provide the first evidence for a specific melatonin receptor subtype, MT2, that may be involved in melatonin-induced immune enhancement.

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Specific binding of 2-[125I]iodomelatonin by rat splenocytes: characterization and its role on regulation of cyclic AMP production

Cited by 66 publications

References 28 publications

Melatonin Involvement in Immunity and Cancer

Melatonin Involvement in Immunity and Cancer

Melatonin and β-Endorphin Changes in Children Sensitized to Olive and Grass Pollen after Treatment with Specific Immunotherapy

Melatonin Receptor Subtype MT2 (Mel 1b) and Not mt1 (Mel 1a) Is Associated with Melatonin-Induced Enhancement of Cell-Mediated and Humoral Immunity

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