Pineal melatonin biosynthesis is regulated by the circadian clock located in the suprachiasmatic nucleus of the hypothalamus. Melatonin has been found to modulate the learning and memory process in human as well as in animals. Endogenous melatonin modulates the process of newly acquired information into long-term memory, while melatonin treatment has been found to reduce memory deficits in elde...

A review of the different publications dealing with melatonin in humans shows that this field has been very active in the last few years. Normative melatonin values have been defined. Various relationships between melatonin and other traits have been studied, such as sleep, circadian rhythm, surgical stress and anaesthesia. Age-related melatonin studies and melatonin during depression and other...

Pineal hormone melatonin is widely used in the treatment of disorders of circadian rhythms. The presence of melatonin receptors in various animal tissues motivates the use of this hormone in some other diseases. For this reason, in recent years investigators continued the search for synthetic analogues of melatonin which are metabolically stable and selective to receptors. This review includes ...

Melatonin is increasingly used for the treatment of sleep disorders. Surge-sustained formulations consisting of combined immediate release and controlled release dosing may mimic the endogenous melatonin physiologic profile. However, relatively little is known about the pharmacokinetic properties of low-dose (<0.5mg) and high-dose (>2mg) melatonin in a combined immediate release/controlled rele...

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 rat...

Human benign prostatic epithelial cells contain functional melatonin receptors that can suppress cell growth and viability. The development of benign prostatic hyperplasia in men is assumed to result from androgen-estrogen imbalance. The impact of sex steroids on melatonin receptors in human benign prostate epithelial cells was investigated. The suppression by melatonin of [3H]thymidine incorpo...

Melatonin is synthesized and released into the circulation by the pineal gland in a circadian rhythm. Melatonin has been demonstrated to differentially alter blood flow to assorted vascular beds by the activation of different melatonin receptors in animal models. The purpose of the present study was to determine the effect of melatonin on blood flow to various vascular beds in humans. Renal (Do...

Delirium is associated with circadian rhythm disruption. In this study we have explored whether circadian variation of melatonin is an indicator for delirium. Melatonin levels were determined from the first day of hospitalization and up to three days after the onset of delirium. Patients who did not developed delirium exhibited a daily melatonin rhythm, while in patients that developed delirium...

A number of studies have suggested that melatonin possesses anticancer properties. However, conflicting data exists with regard to the role of melatonin in the treatment of cancer. In the present study, the effects of melatonin on the transcriptional regulation of three genes associated with cell proliferation (Nestin, Bmi-1 and Sox2), and on C6 glioma cell survival and viability, were investig...

Melatonin is an indoleamine produced from the amino acid l-tryptophan, whereas metabolites of melatonin are known as kynuramines. One of the best-known kynuramines is N¹-acetyl-N¹-formyl-5-methoxykynuramine (AFMK). Melatonin has attracted scientific attention as a potent antioxidant and protector of tissue against oxidative stress. l-Tryptophan and kynuramines share common beneficial features w...