The Effort Of Melatonin And Energy Balance On The Expression Of RFRP-3Gene In Rat

RFRP-3is the only hypothalamic neuropeptide yet indicated that has capacity torestrain the HPG axis. RFRP-3plays a crucial role in the modulation of HPG axisfunction as a critical negative modulator between different species in spite of fewspecialized study. Direct and indirect evidences have indicated that RFRP-3plays animportant role In the GnRH system and Pituitary gonadtropic cells level in all animalsthat have been studied so far.The mechanism by which RFRP-3contributes to the function of HPG axis ispoorly understood at present. The patterns by which melatonin, estrogen and kisspeptinregulate the expression of RFRP-3have not been studied in detail. In addition, and itsfunction in the processes of reproductive regulation of Energy metabolism is not cleareither.This research①detected the expression ofRFRP-3in growing mice that have beentaken caloric restriction to evaluate if RFRP-3involved in reproduction suppressioncaused by insufficient energy supply;②studied the influences of n exogenousmelatonin on expression of RFRP-3gene in hypothalamus and testicles,and KISS-1gene in hypothalamus by melatonin intravenous injection. The results are as follows:①In this study of association between the expression of RFRP-3and energybalance: The individual development were affected significantly after caloric restrictiontreatment in mice. Compared to mice with unlimited food supply, lack of energy supplyresulted in significantly smaller weight and less frequently activity; the growth of ovaryand development of follicles were restrained significantly. Under the status of caloricrestriction treatment, the expression level of RFRP-3gene was increased,meanwhile,theexpression of NPY gene was down regulated; The expression of RFRP-3and NPY havetwo opposite exchange tendencies under caloric restriction status, indicate that RFRP-3gene may play a role in the modulation of caloric restriction treatment to reproduction.②In the study of effect of exogenous melatonin to the expression of RFRP-3gene:The expression of RFRP-3gene and KISS-1gene in hypothalamus have no significantdifference among four groups after melatonin injection. However, melatonin injectionresult in an up regulated tendency in the expression of RFRP-3gene and a downregulated tendency in the expression of KISS-1gene, while no significantly differenceexit. The expression of RFRP-3gene presented a down regulated tendency after injection of inhibitor Luzindole, while the expression of KISS-1gene presented a downregulated tendency. Besides, melatonin injection increased the expression of RFRP-3gene significantly. We suspect that, exogenous melatonin has the capability to suppressthe expression of KISS-1gene and promote the expression of RFRP-3genesimultaneously.