In humans, N-acetyl-5-methoxytryptamine (melatonin), a neurohormone widely found in plants and animal sources, is synthesized from serotonin primarily by the pineal gland. However, it it is also produced in a number of other areas, e.g. the gastrointestinal tract. Melatonin regulates various biological and physiologic body functions and its role in the regulation of circadian rhythms, particula...

In humans, N-acetyl-5-methoxytryptamine (melatonin), a neurohormone widely found in plants and animal sources, is synthesized from serotonin primarily by the pineal gland. However, it it is also produced in a number of other areas, e.g. the gastrointestinal tract. Melatonin regulates various biological and physiologic body functions and its role in the regulation of circadian rhythms, particula...

MAX 350 WORDS) Melatonin is currently proposed to be synthesized in non-photosensitive organs of vertebrates, besides its well-known sites of synthesis, the pineal gland and the retina. However, very few studies have demonstrated gene expression of MEL synthesizing enzymes in extrapineal and extraretinal locations. In the present study, present study focuses on the circadian expression of the t...

Monoamine oxidase B (MAO-B) is an outer mitochondrial membrane-bound enzyme that catalyzes the oxidative deamination of arylalkylamine neurotransmitters and has been a target for a number of clinically used drug inhibitors. The 1.7-A structure of the reversible isatin-MAO-B complex has been determined; it forms a basis for the interpretation of the enzyme's structure when bound to either revers...

PURPOSE Photoreceptor differentiation involves the activation of two specific sets of genes; those encoding the proteins of the phototransduction cascade and those encoding the enzymes of the melatonin synthesis pathway, arylalkylamine N-acetyltransferase (AANAT) and hydroxyindole O-methyltransferase (HIOMT). The purpose of the present study was to examine the conditions of AANAT and HIOMT gene...

Melatonin is a possible protective agent in postburn gut pathophysiological dynamics. We investigated the role of endogenously-produced versus exogenously-administered melatonin in a major thermal injury rat model with well-characterized gut inflammatory complications. Our rationale is that understanding in vivo melatonin mechanisms in control and inflamed tissues will improve our understanding...

Two clinical forms of functional dyspepsia (FD) are listed in the Rome III criteria: postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS), differing in the recurrence of ailments depending on the diet. Continuous EPS (CEPS) is observed in some EPS patients, also at night, but its cause is still unknown. We showed previously that melatonin (MEL) homeostasis may be associated w...

Melatonin (MT), an indole formed enzymatically from L-trytophan (Trp), was first discovered in the bovine pineal gland in 1958 by Lerner et al. Melatonin is the most versatile and ubiquitous hormonal molecule produced not only in the pineal gland but also in various other tissues of invertebrates and vertebrates, particularly in the gastrointestinal tract (GIT). This review focuses on the local...

SECONDARY HYPERPARATHYROIDISM is an almost inevitable consequence of untreated chronic kidney disease (CKD), resulting in disordered skeletal remodeling and mineralization defects. Thus, due to the high circulating levels of parathyroid hormone (PTH), both osteoblast and osteoclast surfaces may be augmented and ultimately bone volume may be reduced (11). In CKD, synthesis of 1,25 dihydroxyvitam...