Endocrine 

About: Endocrine is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Diabetes mellitus & Medicine. It has an ISSN identifier of 1355-008X. Over the lifetime, 5600 publications have been published receiving 119339 citations.

Functional MT1 and MT2 melatonin receptors in mammals.

Abstract: Melatonin, dubbed the hormone of darkness, is known to regulate a wide variety of physiological processes in mammals. This review describes well-defined functional responses mediated through activation of high-affinity MT1 and MT2 proteinteoupled receptors viewed as potential targets for drug discovery. MT1 melatonin receptors modulate neuronal firing, arterial vasoconstriction, cell proliferation in cancer cells, and reproductive and metabolic functions. Ativation of MT2 melatonin receptors phase shift circadian rhythms of neuronal firing in the suprachiasmatic nucleus, inhibit dopamine release in retina, induce vasodilation and inhibition of leukocyte rolling in arterial beds, and enhance immune responses. The melatonin-mediated responses elicited by activation of MT1 and MT2 native melatonin receptors are dependent on circadian time, duration and mode of exposure to endogenous or exogenous melatonin, and functional receptor sensitivity. Together, these studies underscore the importance of carefully linking each melatonin receptor type to specific functional responses in target tissues to facilitate the design and development of novel therapeutic agent.

A review of the multiple actions of melatonin on the immune system

Abstract: This review summarizes the numerous observations published in recent years which have shown that one of the most significant of melatonin’s pleiotropic effects is the regulation of the immune system. The overview summarizes the immune effects of pinealectomy and the association between rhythmic melatonin production and adjustments in the immune system as markers of melatonin’s immunomodulatory actions. The effects of both in vivo and in vitro melatonin administration on non-specific, humoral, and cellular immune responses as well as on cellular proliferation and immune mediator production are presented. One of the main features that distinguishes melatonin from the classical hormones is its synthesis by a number of nonendocrine extrapineal organs, including the immune system. Herein, we summarize the presence of immune system-synthesized melatonin, its direct immunomodulatory effects on cytokine production, and its masking effects on exogenous melatonin action. The mechanisms of action of melatonin in the immune system are also discussed, focusing attention on the presence of membrane and nuclear receptors and the characterization of several physiological roles mediated by some receptor analogs in immune cells. The review focuses on melatonin’s actions in several immune pathologies including infection, inflammation, and autoimmunity together with the relation between melatonin, immunity, and cancer.

Antioxidative protection by melatonin: multiplicity of mechanisms from radical detoxification to radical avoidance.

Abstract: Melatonin has been shown to protect against oxidative stress in various, highly divergent experimental systems. There are many reasons for its remarkable protective potential. Signaling effects comprise the upregulation of antioxidant enzymes, such as superoxide dismutases, peroxidases, and enzymes of glutathione supply, down-regulation of prooxidant enzymes, such as nitric oxide synthases and lipoxygenases, and presumably also the control of quinone reductase 2. Other mechanisms are based on direct interactions with several reactive oxygen and nitrogen species. Among these reactions, the capacity of easily undergoing single-electron transfer reactions is of particular importance. Electron donation by melatonin is not only an aspect of direct radical scavenging, but additionally represents the basis for formation of the protective metabolites AFMK (N1-ace-tyl-N2-formyl-5-methoxykynuramine) and AMK (N1-acetyl-5-methoxykynuramine). Recent investigations on mitochondrial metabolism indicate that melatonin as well as AMK are capable of supporting the electron flux through the respiratory chain, of preventing the breakdown of the mitochondrial membrane potential, and of decreasing electron leakage, thereby reducing the formation of superoxide anions. Radical avoidance is a new line of investigation, which exceeds mitochondrial actions and also comprises antiexcitatory effects and contributions to the maintenance of internal circadian phase relationships.

Epidemiology, trends, and morbidities of obesity and the metabolic syndrome.

Abstract: Obesity has been described as an epidemic because of the rapid increase in the number of overweight and obese individuals over the past 20 yr. This increasing prevalence of obesity is a worldwide phenomenon affecting both children and adults. The metabolic syndrome is a constellation of central adiposity, impaired fasting glucose, elevated blood pressure, and dyslipidemia (high triglyceride and low HDL cholesterol). When three of these five criteria are present, the risk of cardiovascular disease and diabetes is increased 1.5-to 2-fold. As body weight, expressed as the BMI, rises, there are a number of other diseases that are associated with it. First, life spain is shortened and the risk of sudden death increases. Second, the risk of diabetes, gall bladder disease, hypertension, heart disease, osteoarthritis, sleep apnea, and certain forms of cancer also increase.

The incidence and prevalence of thyroid autoimmunity.

Abstract: The thyroid gland is the most common organ affected by autoimmune disease. Other autoimmune diseases, most notably type 1 diabetes mellitus, are increasing in incidence. It is unknown whether autoimmune thyroid diseases are following the same pattern. This review summarizes studies of autoimmune thyroid disease incidence and prevalence since 1950, not only for these measures of occurrences, but also for commenting on identified risk factors for thyroid autoimmunity. We find that incidence of autoimmune thyroid disease is currently higher than in historic series although the studies are so variable in design, patient population, disease definition, and laboratory methods that it is impossible to tell whether this difference is real. Further research is required to assess the possibility of changing disease patterns of autoimmune thyroid disease as opposed to simple changes in diagnostic thresholds.