The aim of the present study was to elucidate the direct effects of melatonin on bladder activity and to determine the mechanisms responsible for the detrusor activity of melatonin in the isolated rat bladder. We evaluated the effects of melatonin on the contractions induced by phenylephrine (PE), acetylcholine (ACh), bethanechol (BCh), KCl, and electrical field stimulation (EFS) in 20 detrusor...

Binding of melatonin was examined in the retina of Rana pipiens. When intact frog retinas were incubated with 3H-melatonin and processed for autoradiography, most of the radioactivity was localized to the melanosomes of the retinal pigment epithelium-choroid (RPE-choroid) and to the outer plexiform layer of the retina. Melanosome-enriched fractions of the RPE-choroid and membrane-enriched fract...

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 correla...

The mammalian circadian system is composed of numerous oscillators, which gradually differ with regard to their dependence on the pacemaker, the suprachiasmatic nucleus (SCN). Actions of melatonin on extra-SCN oscillators represent an emerging field. Melatonin receptors are widely expressed in numerous peripheral and central nervous tissues. Therefore, the circadian rhythm of circulating, pinea...

The pineal hormone melatonin participates in circadian, seasonal, and reproductive physiology. The presence of melatonin binding sites in human brain and peripheral tissues is well documented. However, in the mammalian adrenal gland, low-affinity melatonin binding sites have been detected only in the rat by some but not all authors. Conflicting evidence for a regulatory role of melatonin on adr...

Background Melatonin (N-acetyl-5- methoxytryptamine) is mainly synthesized and secreted in the pineal gland, ovary, testes, bone marrow, retina and lens in mammalian species. It is involved in the detoxification of ROS and protects embryos from oxidative damage. Melatonin acts as a potential free radical scavenger, including peroxyl radical and hydroxyl radical. In addition, it can stimulate th...

objective: the goals of the study are evaluation the effect(s) of food deprivation as a social stress on testis structure. we also investigated the effects of melatonin treatment as an antioxidant component and inequality on the effect(s) of food deprivation. methods: we investigated the improving effects of melatonin and social stress (food deprivation) on 42 male rats in 7 groups including co...

Recent studies have revealed that melatonin exerts strong anti-apoptotic effects. Retina secretes melatonin, and melatonin receptors are distributed in almost all the layers of retina, including the layer of retinal pigment epithelial (RPE) cells. However, it is not known whether melatonin inhibits apoptosis through its anti-oxidant effects and how it works in RPE cells. Here, we show that mela...

Melatonin, a pineal hormone, because of its wide activity spectrum, is a subject of much current interest for biologists and physicians. It has been demonstrated that pineal gland is not an exclusive source of melatonin synthesis. Melatonin synthesis has been found in different sites of the organism, and a major source of extrapineal melatonin is the gastrointestinal tract. The role of melatoni...

Melatonin (N-acetyl-5-methoxytryptamine) plays important roles in regulating both biotic and abiotic stress tolerance, biological rhythms, plant growth and development. Sharing the same substrate (tryptophan) for the biosynthesis, melatonin and auxin also have similar effects in plant development. However, the specific function of melatonin in modulating plant root growth and the relationship b...