A review on Melatonin Binding Sites

 

The discovery of melatonin binding sites has been done in the year 1984 by Vakkuri and it has been achieved by the synthesis of 2 indomelatonin. It has now been used in several studies to understand the melatonin biding sites in a range of tissues and species. The discovery of this radioligand and autoradiograph studies have paved the way of many hidden insights to light. Using this radioligand both the high and low affinity binding sites has been affirmed and has been named as ML1 and ML2. and the peculiarity of the binding sites are the low affinity of expression. In humans the tissue distribution of MT1 and MT2 levels has been studied mainly in the brain. The expressions of the receptors are mainly seen in suprachiasmatic nucleus, hypothalamus, hippocampus, cerebellum and cerebral arteries. MT1 is expressed in retina, adipose tissue and the kidney tissue and MT2 is expressed in the adipose and kidney tissues as well. Another MT3 melatonin receptor has been identified as the form of human homologue of the cytoplasmic reductase. Expression of melatonin binding sites has also been found in the liver. Liver represents as the most important organ for melatonin metabolism and the hormone undergoes 6 hydroxylation followed by sulphate or glucoronide conjugation. 6 sulphatoxymelatonin is the major urinary metabolite of melatonin in humans and the measurement provides simple and important assessment of melatonin secretion.

Source:- 1. Physiological and metabolic function of melatonin, Jaione Barrenetxe, Martinez Alfred

https://www.researchgate.net/profile/Martinez-Alfredo/publication/8362211_Physiological_and_metabolic_functions_of_melatonin/links/563ccb6908ae8d65c0116c3e/Physiological-and-metabolic-functions-of-melatonin.pdf


Comments

Post a Comment

Popular posts from this blog

Pineal gland and its effect on maintaining circadian rhythm

  "Pineal gland or body is a small glandular structure that projects from the dorsal diencephalon and lies just posterior to the third ventricle. In the past, the pineal body is figured predominantly in philosophic and religious writings, for Devartes, it was the seat of soul. When this idea was discredited, the pineal gland was relegated to the states of a vestigial organ. The identification of melatonin, the pineal hormone followed by recognition of its role in maintaining biologic rhythms and the modulating effects on its secretion by the circadian light dark circle-revived scientific interest in the structure. Even though the hormone was found to have an indirect effect on several other nuro-endocrine systems, neurologist took little interest in the pineal gland because oblation of the gland in humans, with attendant loss of most of its circulating melatonin leads to few if any clinical changes.             It is the cycl...
Read more

Reactive Oxygen Species

Introduction The increasing concentration of oxygen level in the atmosphere near about 2.5 billion ago, oxygenic photosynthesis by cyanobacteria leads to the evolution of aerobic respiration leading to the development of complex eukaryotic organisms. All the aerobic organisms  depends upon the cellular respiration and some of the derivatives of oxygen are highly toxic for the cells. Reactive oxygen species, reactive oxygen intermediates and reactive nitrogen species have been used to define the highly reactive oxygen bearing molecules. Hydroxyl and peroxyl radicals, hydrogen peroxide and superoxide radical anions are some of the species responsible for the damage of the fatty acids, DNA and proteins as well as other cellular components. The redox reaction is typically involved in controlling production of reactive oxygen and nitrogen species. They can, in turn, react with specific functional group of target proteins like clusters, cysteines  etc. that lead to covalent protein ...
Read more

Xanthine oxidase

  In higher animals nucleotides resulting from degradation of the nucleic acids by the action of nucleases usually undergo enzymatic hydrolysis to yield, ultimately, the free purine and pyramidine bases. If not salvaged and reused, the free bases are degraded further and the end products excreted. In some vertebrates, including the primates, the Dalmatianm dog, birds, and some reptiles, the end product of purine degradation is uric acid, whereas in other mammals and reptiles, and also in mollusks, the end product is allantoin. In fishes, allantoin is broken down to allantoic acid and urea. In aquatic invertebrates ammonia is the major nitrogenous end product of purine catabolism. Curiously, guanine is the excretory form of purines in the spider and the pig.   The degradation of purines to the end product uric acid in man has been intensively studies, since genetic aberrations of this pathway are known. The major purines adenine and guanine are first converted into xanthine w...
Read more