Elevated plasma homocysteine level promotes atherosclerosis in blood vessels due to, among others, generation of reactive oxygen species and reduction of nitric oxide bioavailability. The aim of this study was to investigate whether melatonin administration reduces plasma homocysteine level in rats consuming increased doses of methionine in the diet. The trial lasted for two months. The rats we...

The aim of this study was an analysis of the relationship between pineal hormone melatonin level and long-term occupational exposure to elemental mercury vapour (Hg) of ex-mercury miners. Melatonin (MEL) is a hormonal product of the pineal gland. Hg accumulation in the pineal gland in ex-miners could modify the synthesis of melatonin and there are no data available in the scientific literature ...

Two receptors (CKA and CKB) of the G protein-coupled melatonin receptor family were cloned from chick brain. CKA encodes a protein that is 80% identical at the amino acid level to the human Mel1a melatonin receptor and is thus designated the chick Mel1a melatonin receptor. CKB encodes a protein that is 80% identical to the Xenopus melatonin receptor and defines a new receptor subtype, the Mel1c...

The present study includes 50 patients suffering from psychological stress disorders like thyrotoxicosis and anxiety neurosis. Biochemical estimation of melatonin was done in all these cases prior to treatment and 3 months after appropriate treatment. A significant increase in the level of melatonin was observed in thyrotoxic and anxiety neurotic cases. In all these cases, after therapy the lev...

Background: After radiation therapy (RT), some health hazards including DNA damages may occur where melatonin can play a protective role due to free radical generation. On the other hand, serious accidental overexposures may occur during RT due to nuclear accidents which necessitate the need for study on exposure to high-dose radiations during treatments.Objective: The aim of this study was to ...

BACKGROUND The purpose of this study was to evaluate the dynamics of plasma melatonin secretion in patients with type 2 diabetes mellitus and diabetic retinopathy. METHODS Plasma melatonin levels were measured by high-performance liquid chromatography in 56 patients. Patients were divided into a diabetic group (30 patients) and a nondiabetic group (26 patients). The diabetic group was divided...

OBJECTIVES Vagal pathways in gastrointestinal tract are the most important pathways that regulate ischemia/reperfusion (I/R). Gastrointestinal tract is one of the important sources of melatonin production. The aim of this study was to investigate probable protective effect of the interaction between vagus nerve and melatonin after I/R. MATERIALS AND METHODS This study was performed in male ra...

Xenopus laevis retinas, like retinas from all vertebrate classes, have endogenous circadian clocks that control many aspects of normal retinal physiology occurring in cells throughout all layers of the retina. The localization of the clock(s) that controls these various rhythms remains unclear. One of the best studied rhythmic events is the nocturnal release of melatonin. Photoreceptor layers c...

To investigate the protective effects of melatonin against high-LET ionizing radiation, V79 Chinese hamster cells were irradiated with 100 keV/microm carbon beam. Parallel experiments were performed with 200 kV X-rays. To avoid the impact from extra solvents, melatonin was dissolved directly in culture medium. Cells were cultured in melatonin medium for 1 hr before irradiation. Cell inactivatio...