Melatonin treatment is effective in treating sleep onset problems in children with delayed melatonin onset, but effects usually disappear when treatment is discontinued. In this pilot study, we investigated whether classical conditioning might help in preserving treatment effects of melatonin in children with sleep onset problems, with and without comorbid attention deficit hyperactivity disord...

Melatonin, a circadian hormone with marked antioxidant properties, has been shown to protect against ischemia-reperfusion myocardial damage, especially when administered during reperfusion period. Melatonin has cardioprotective properties via its direct free radical scavenging and its indirect antioxidant activity. Melatonin efficiently interacts with various reactive oxygen and reactive nitrog...

Insomnia is a serious worldwide health threat, affecting nearly one third of the general population. Melatonin has been reported to improve sleep efficiency and it was found that eating melatonin-rich foods could assist sleep. During the last decades, melatonin has been widely identified and qualified in various foods from fungi to animals and plants. Eggs and fish are higher melatonin-containi...

Feeding regulation by monoamines, neuropeptides and certain hormones has been studied in fish, but a possible role of melatonin is unknown. The purpose of the present study was to investigate the effects of melatonin on food intake in goldfish. Fishes were housed in 12L:12D and injected with different doses of either melatonin or 2-iodomelatonin. Two routes of administration, intracerebroventri...

The possible interaction of melatonin receptors and D1 dopamine receptors was investigated in neural cells prepared from embryonic day 8 chick retinas and cultured for 6 d. Dopamine stimulated cAMP accumulation in cultured retinal cells. This effect of dopamine was antagonized by addition of dopamine receptor antagonists (haloperidol and SCH23390) or melatonin receptor agonists (melatonin, 2-io...

Melatonin (N-acetyl-5-methoxytryptamine) is an indolamine hormone produced by the pineal gland that works to regulate sleep/wake cycles and activity rhythms. The effects of melatonin in metabolism are far from understood. Melatonin was injected into the fiddler crab, Uea pugilator, to investigate the effects of melatonin on hemolymph glucose and lactate levels. Following injection at t=O, hemol...

To identify the characteristics of the oscillator located in the pineal organ, we examined the effects of temperature and light on melatonin secretion rhythm using pineal organs in cultures. At 20 degrees C, the melatonin rhythm was obvious: low secretion during the daytime and high during the nighttime. When the temperature was lowered from 20 to 10 degrees C, the melatonin rhythm disappeared....

Background. Sleep disturbances and cognitive dysfunction are common in patients with breast cancer. Disturbed sleep leads to poor cognitive performance and exogenous melatonin may improve sleep and attenuate cognitive dysfunction. We hypothesized that melatonin would improve sleep and cognitive function after surgery. Methods. This study reports secondary endpoints from a randomized, double-bli...

The human skin is not only a target for the protective actions of melatonin, but also a site of melatonin synthesis and metabolism, suggesting an important role for a local melatoninergic system in protection against ultraviolet radiation (UVR) induced damages. While melatonin exerts many effects on cell physiology and tissue homeostasis via membrane bound melatonin receptors, the strong protec...

In this paper evidence that supports a new role for melatonin as a negative endogenous regulator of cytosolic phospholipase A(2) (cPLA(2)) is presented. When rat pineal glands were incubated in culture, time-dependent release of arachidonic acid (AA) was observed, which was significantly inhibited by a known 85-kDa cPLA(2) inhibitor, methyl arachidonyl fluorophosphonate. Co-incubation with mela...