Study Onthe Effect Of Melatonin On Growth、metabolism In Rat Based On Metabolomics And Gene Chip

The present study was aimed to investigate the effect of melatonin on rat growth and fat distribution.(Method) Total 50 SD rats with similar age and body weight were randomly divided into 5 groups, i.e. normal diet group(ND), normal diet with melatonin group(ND+MT), fat supplementation group(FS), fat supplementation with low dose melatonin group(FS+LMT) and high dose melatonin group(FS+HMT), each of 10. Fat supplementation was refer to adding 10% lard into normal diet. ND+MT 、 FS+LMT 、 FS+HMT administrated orally 10mg/kg BW,2mg/kg BW,20mg/kg BW of melatonin solution every day, respectively and daily gain of every rat was recorded. On the 60 th day, blood and fat samples were collected. After that, blood biochemistry and liver histopathology via Oil red O staining were conducted. Metabolomics using1H-NMR, which could identify organisms biomarkers and detect the metabolic stateat different physiological state, was adopted to research the changes of metabolites levels and in liver of ND、ND+MT、FS、FS+MT group. Under the effect of MT, the animal body organs, including liver various metabolic pathways are affected, the relevant metabolites must have different degrees of change, with metabonomics method can accurately detect the MT full influence mainly markers of liver metabolism, determine the impact the way and degree of hepatic metabolism。ND, ND + MT group rat liver samples using gene chip method, from the gene level to further explore the MT effects on rats.Results showed the result showed that:(1) compared with ND, the level of hepatic LCFA, total cholesterol, average daily gain, liver weight, omentum majus fat, perirenal fat, epididymis fat in ND+MT were decreased significantly(P<0.05); Not only omentum majus fat and epididymis fat in FS+LMT and FS+HMT but also hepatic LCFA acid and average daily gain in FS+HMT were decreased significantly in comparsion with FS(P<0.05); There was a significant difference of perirenal fat and epididymisadipose accumulation between ND and FS(P<0.05). Melanin has a dose-related effect that can reduce the growth rate of rats, decrease the fat content in the liver and change the distribution of body fat. In present study, high dose melatonin have a more obvious impact.(2) Totally, there are 63 metabolites were detected via 1H-NMR based on its identification database,including amino acids, organic acids, sugars, amine and vitamins.13 out of 63 metabolites differ significantly among groups. 5 metabolites between ND+MT and FS were notable, and 8 metabolites were different significantly between FS and FS+LMT compared with ND. Further analysis indicates that these metabolites were related to amino acid metabolism, fat metabolism and carbohydrate metabolism in hepatic cells.(3) From the gene chip analysis of ND and ND + MT liver, combined with result of metabonomics test, found 16 genes expressed differently associated with metabonomics results, respectively belong to sugar metabolism, fatty acid metabolism, amino acid metabolism pathway, from which,we can combine gene and metabonomics, making two kinds of test methods complement each other, a more scientific and comprehensive research also melatonin effects on metabolism in rats.Conclusion:(1) Under the same diet condition,melanin has a dose-related effect that can reduce the growth rate of rats, decrease the fat content in the liver and change the distribution of body fat.(2) Metabolomic technology could precisely detectcharacteristic metabolites in liver under MT as well as provideenough informationto diagnose hepatic metabolism pathway relevant to clarifythe mechanism of liver sufferingfrom MT.(3) MT canenhance the expressionof key enzyme genein the rat liver metabolism pathways.