| Melatonin(N-acetyl-5-Methoxytryptamine) was discovered by a Lerner and his colleagues[l]as the principal hormone of vertebrate pineal gland ,an unpaired appendage of the brain in most vertebrates and named by him after its effects on amphibian melanophore.However,it is now known that many cells and tissues synthesis and the nature of organisms,melatonin is secreted in the night,thus ,melatonin is identified as an endocreine index of the darkness and referred to as darkness hormone[3].Melatonin has aslo been called by other names,such as nature's sleeping pill for it role in sleep-wake cycles,and circadian glue for its increasing importance in the regulation of circadian and circannual physiological and behavioural functions, moreover it is also involved in the regulation of the immune respone and various CNS activies, in the last decade,considerable attention has been devoted to the pharmacology of melatonin in view of its potential applications in various therapeutic areas. Recently several authors presented in vitro data showing the ability of melatonin to act as a free radical scavenger and a general antioxidant,thus its activity as a hydroxyl radical scavenger,evaluatedusing the eletron paramagnetic resonance(EPR)technique,is higher than that of glutathione,mannitol,and other indole strutures such as serotonin or trytophan similarly.its efficacy as a peroxyl radical scavenger evaluated in the B -phycoenghrin model is higher than that of trodox ,vitaminC and GSH.the well-known radical scavengers.The current interest in melatonin is wintnessed by the growing number of scientific papers directly or indirectly dealing with this molecule, in the last 10 years,the mean number of articles has doubled and reports on new compoundsacting at the melatonin receptors abound,although the search for a clear therapeaatic role for these ligands is still under way Beside the scientific interest ,there is a contemporary ,but largely independent,explosion of a free market of various products containing MT,Which have been presented at antiage agents protecting against differe kinds of injuries,although this action still lacks a solid scientific foundation.indeed while a number of physiological action of MT are coming to light ,the exact role and the the real therapeutic benefit of this compound still remain unclear ,both have been the subject of debate.with a lot of potential actions still to be fully demonstrated and with some mechanisms deserving more clarification ,in sense,the appellation of the hormone of darkness, attributed to MT beacause of its characteristic concentration/time profile,seems extremely appropriate.However ,the lack of a simple,sensitive ,and reliable method for mersuring MT has been an obstacle to the elucidation of its physiological and pathological role[3-5] .after initial attempts with bioassay, gas chromatography-mass spectrometry for quantifying Mt in body fluids was tried,followed by HPLC.the major limitations to these techniques were expense,low throughput,extensive sample work-up before assay[4,5].In order to further study the funcation of pineal gland,also in order to deeper understand drug-receptor interactions, therefore better to build MT receptor models and to design new seletive ligands.which applying solid foundation for MT and its analoges's therapeutical application.we produce and characterizate monoclonal antibodies to melatonin. Anti-melatonin monoclonal antibodies of higher titer , affinity and good sensitivity were obtained by coupling MT to bovine serum albumin with formaldehyde and by immunizing mice with multifocal intra-dermal injections.we obtained 6 strains of hybridoma, all of themsecreting specific antibodies to MT,we apply antibodies to determinate free MT inhuman serun with group-selective immunoassay technique.An inhibition curve for MT was obtained in the range of 50pg to30ng ,and 1.4ng of MT inhibited the value of the assay by half. We evaluate the specificity of antibodies by determination of cross-reactivity of several analogues ,The MoAbs recogn...
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