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Query: UMLS:C0917801 (insomnia)
 10,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Melatonin blanches the skin of frogs, whitens the fur of hamsters, and sometimes makes the gonads atrophy. It is remarkable that such a hormone would be put forward as a defense against ageing. We have been examining excretion of the urinary metabolite of melatonin, 6-sulphatoxymelatonin (6-SMT), in 150 postmenopausal women, in 72 volunteers over the age of 60 years who complained of insomnia or depression, and in 20 healthy younger adult controls, aged 18-40 years. The acrophase or fitted peak of 6-SMT excretion was computed as a marker of the timing of the circadian system. Total daily excretion of 6-SMT was not significantly related to total sleep time, wake-within-sleep or sleep complaints. Nevertheless, whereas the 20 controls displayed a normal range of 6-SMT acrophases from 01.32 to 05.44 h, 42% of the postmenopausal women and 48% of the symptomatic elders had acrophases outside this normal range. Those volunteers with more deviant acrophases displayed more disturbed sleep and more sleep complaints. These data suggest that melatonin is a useful marker of circadian rhythm phase disorders, but suggest a need for more caution in melatonin administration.
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PMID:Melatonin: marvel or marker? 955 93

Melatonin is being increasingly promoted as a therapeutic agent for the treatment of jet lag and insomnia and has been recently suggested to act as an efficient free-radical scavenger. In the present work, its mechanisms of action for scavenging hydroxyl radicals have been investigated using semiempirical AM1 and density functional theory (DFT) computational tools. Two different reactions were proposed as follows: one involving the abstraction of an indolic hydrogen to yield a neutral radical and another involving the addition of the hydroxyl radical to the indolic moiety. Our results show that, from a thermodynamical standpoint, melatonin may directly scavenge hydroxyl radicals both in vacuum and in aqueous solution. The structural requirements for free-radical-trapping ability have been examined comparing melatonin with related indoles. Computational data suggest that 5-methoxy and N-acetyl groups of melatonin do not significantly affect its thermodynamical capacity of free-radical trapping. The present results support experimental data on the potential of melatonin as a physiological or pharmacological antioxidant agent.
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PMID:Reactions of melatonin and related indoles with free radicals: a computational study. 973 93

The pineal product melatonin is involved in the regulation of the sleep/wake cycle in humans. In blind individuals and in people travelling through time zones, melatonin rhythms are sometimes unsynchronized with the diel cycle, and nocturnal sleep may be disturbed. Low or distorted melatonin rhythms have repeatedly been reported in middle aged and elderly insomniacs. Melatonin administration effectively synchronized the sleep wake cycle in blind individuals and in subjects suffering from jet lag and advanced sleep onset in subjects suffering from delayed sleep phase syndrome. In elderly insomniacs, melatonin replacement therapy significantly decreased sleep latency, and/or increased sleep efficiency and decreased wake time after sleep onset. In addition, melatonin substitution facilitated benzodiazepine discontinuation in chronic users. These data show an association between melatonin rhythm disturbances and difficulties to promote or maintain sleep at night. Specific melatonin formulations may be useful to treat circadian-rhythm-related sleep disorders and age-related insomnia.
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PMID:The use of melatonin for the treatment of insomnia. 1008 68

We studied the usefulness of melatonin for sleep disorders and emotional/behavior disturbances of patients with developmental disorders. The efficacy and side effects of melatonin at bedtime were evaluated in 50 children and young adults with sleep disorders (3-28 years old, 41 males and 9 females, autism [AU] in 27 patients, mentally retardation [MR] in 20 patients, and severe motor and intellectual disability [SMID] in 3 patients). The sleep disorders consisted of various types of insomnia in 44 patients and of circadian rhythm sleep disorders in 6 patients. Thirty nine of the insomnia patients and 3 of the circadian rhythm sleep disorder patients experienced improvement in response to melatonin. In some cases, the efficacies were diminished after the daily medication of melatonin. With the emotional/behavior disturbances, excitabilities were often improved in cases whose sleep disorders were also improved. There was almost no change in contrariness, stereotyped behavior and in school/workshop refusal. Melatonin at bedtime was efficacious in 42 of the 50 patients with sleep disorders. In 17 patients, there were side effects (residual drowsiness on the next morning, awakening in the middle of sleep, excitement after awakening and before going to sleep, etc.). But these side effects were not serious. The effects of melatonin were influenced by the type of sleep disturbances, the factors of the environment and the mental conditions. Taking side effects into account, we judged melatonin to be useful in 34 patients.
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PMID:[Usefulness of melatonin for developmental sleep and emotional/behavior disorders--studies of melatonin trial on 50 patients with developmental disorders]. 1048 68

Insomnia has numerous, often concurrent etiologies, including medical conditions, medications, psychiatric disorders and poor sleep hygiene. In the elderly, insomnia is complex and often difficult to relieve because the physiologic parameters of sleep normally change with age. In most cases, however, a practical management approach is to first consider depression, medications, or both, as potential causes. Sleep apnea also should be considered in the differential assessment. Regardless of the cause of insomnia, most patients benefit from behavioral approaches that focus on good sleep habits. Exposure to bright light at appropriate times can help realign the circadian rhythm in patients whose sleep-wake cycle has shifted to undesirable times. Periodic limb movements during sleep are very common in the elderly and may merit treatment if the movements cause frequent arousals from sleep. When medication is deemed necessary for relief of insomnia, a low-dose sedating antidepressant or a nonbenzodiazepine anxiolytic may offer advantages over traditional sedative-hypnotics. Longterm use of long-acting benzodiazepines should, in particular, be avoided. Melatonin may be helpful when insomnia is related to shift work and jet lag; however, its use remains controversial.
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PMID:Chronic insomnia: a practical review. 1052 87

A children's sleep disorders clinic was started as a project supported by the Swedish National Board for Health and Welfare in 1994. During the first three years 71 children, 21 girls and 50 boys aged 0.5-26 years, were clinically examined by a child neurologist/somnologist and a child psychologist. Psychological follow-up was offered. Twenty-five children were healthy, in the others several types of medical conditions were found. Twenty-five children were mentally retarded. In children with physical impairments the most common sleep problems were circadian sleep disturbances, in the healthy ones habitual insomnias were the most common finding. Taking a detailed history was important for correct sleep diagnosis and was often therapeutic. In healthy children with habitual insomnia psychological support was often successful. Melatonin was of benefit in circadian sleep disorders, and only in these. Other medications were used in a restrictive way, mostly as a temporary support.
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PMID:[Sleep disorders in healthy children follows often a "learnt" behavioral pattern. Diurnal rhythm disturbances are dominating among children with functional disabilities]. 1060 11

There is little information about the interaction between melatonin, sexual steroids and neuroendocrine system in postmenopausal females, even if former research showed that melatonin is clearly involved in human physiology and pathophysiology. We evaluated the overnight urinary excretion of 6-sulfatoxymelatonin (6-SMT) using a radioimmunoassay in 60 postmenopausal women. The group has been divided into patients with insomnia (10), hyperprolactinemia (7), depression (9), obesity (7) and controls (27). Compared to controls 6-SMT values were significantly higher in depressive females. Patients with hyperprolactinemia showed a trend toward a significantly elevated average nocturnal melatonin concentration. Melatonin levels were significantly lower in patients with insomnia and obese postmenopausal females than in controls. Since previous studies described lower melatonin levels in postmenopausal than in premenopausal women, the indication of melatonin therapy, especially for sleep disorders in this collective, can be handled more generously. Melatonin should be prescribed restrictively in patients with depression and in those with hyperprolactinemia. The role of melatonin in obese females remains unclear.
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PMID:Melatonin in postmenopausal females. 1076 39

1. A profound alteration of circadian rhythm of sleep is often a central feature in manic syndrome. Melatonin (MLT) is a main synchronizer of the sleep/wake cycle, playing a role of transduction to brain functioning of informations about periodical environmental changes, i.e. the duration of daylength. 2. In several sleep phase disorders, MLT exerts a therapeutic effect, by normalizing the sleep/wake cycle. 3. Eleven patients, 8 males and 3 females, aged 22-43, meeting DSM IV diagnostic criteria for Bipolar Disorder, Manic Type, were selected for the presence of insomnia not responding to usual hypnotic therapies (benzodiazepine). 4. All the patients were on antimanic treatment. MLT 3 mg per os was administrated at 22.30 h for 1 month, without changing the previous antimanic and hypnotic treatments. All patients showed a significantly longer duration of sleep following MLT add-on. The severity of mania showed a parallel significant decrease. 5. The results of this pilot clinical study suggest that MLT add-on can be useful in antimanic therapy to treat resistant circadian sleep alterations as well as consequently exert a global therapeutic action on the manic state.
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PMID:Melatonin add-on in manic patients with treatment resistant insomnia. 1080 Jul 42

Melatonin has gained recent popularity as a treatment for insomnia and other sleep disorders; however, its cellular effects are unknown. We report the effects of melatonin on the cellular morphology of Chinese hamster ovary (CHO) cells transformed to express the human melatonin receptors, mt1 and MT2. Our results show that melatonin exerts a strong influence on cellular shape and cytoskeletal organization in a receptor-dependent and possibly subtype-selective manner. The cell shape change that we see after a 5-h treatment of these non-neuronal cells with a pharmacological concentration of melatonin consists of the formation of long filamentous outgrowths that are reminiscent of the neurite processes produced by differentiating nerve cells. This morphological change occurs exclusively in cells expressing the mt1 receptor. We find that the microtubule and microfilament organization within these outgrowths is similar to that of neurites. Microtubules are required for the shape change to occur as Colcemid added in combination with melatonin completely blocks outgrowth formation. We demonstrate that the number of cells showing the altered cell shape is dependent on melatonin concentration, constant exposure to melatonin and that outgrowth frequencies increase when protein kinase A (PKA) is inhibited. Concomitant melatonin-dependent increases in MEK 1/2 and ERK 1/2 phosphorylation are noted in mt1-CHO cells only. The production of filamentous outgrowths is dependent on the translation of new protein but not the transcription of new mRNA. Outgrowth number is not controlled by centrosomes but is instead controlled by the polymerization state of the actin cytoskeleton. The results of this work show that the organization of the cytoskeleton is affected by processes specifically mediated or regulated by the mt1 receptor and may represent a novel alternative mechanism for the stimulation of process formation.
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PMID:Melatonin induction of filamentous structures in non-neuronal cells that is dependent on expression of the human mt1 melatonin receptor. 1084 31

(1) In the United States melatonin is just a dietary supplement, but in Europe its status varies from country to country and also over time. It is illegal in some European member states but tolerated or authorised as a drug or dietary product elsewhere. Melatonin, a hormone secreted by the pineal gland, has been on the front cover of magazines throughout the world for its claimed effects on ageing, cancer and many other health problems, opening up a vast potential market. (2) Only its use in jet lag, sleep disorders and advanced cancer has been tested clinically (albeit scantily). (3) Melatonin seems to alleviate jet lag symptoms, but that could be linked to its moderate hypnotic effect. (4) The use of melatonin to treat major insomnia cannot be envisaged until its long-term safety has been proven. With this proviso, and if efficacy is confirmed in sufficiently large comparative trials, melatonin could prove useful for treating major sleep disorders in some patients, especially blind people and those with severe neurological disabilities. (5) According to open trials conducted by a single team, melatonin, alone or combined with interleukin-2, could slightly lengthen the survival of patients with some advanced cancers, but even partial tumour remissions are rare. (6) All other "indications" are based on simplistic hypotheses or purely commercial considerations.
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PMID:Melatonin: interesting, but not miraculous. 1084 53


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