Expression of Kisspeptin/kiss1r System is Down-regulated in the Hypothalamic Arcuate Nucleus of Pubertal Male Rats with High-fat-diet

ObjectiveTo explore the potential function of nutrition on kisspeptin/kisspeptin receptor (kiss1r) system in the arcuate nucleus (ARC) of male rats.MethodsPregnant rats were obtained and male pups were used to establish obesity model. Body parameters and blood samples were evaluated. Immunohistochemistry was used to determine the localizations and protein levels of kisspeptin, kiss1r, and leptin receptor (LepR) immunoreactivity (IR) in ARC. QRT-PCR was used to determine kiss1-, kiss1r-, LepR-, and GnRH-mRNA levels.ResultsThe establishment of obesity model was successful as body parameters and hormones levels changed noticeably. Kisspeptin-, kiss1r-, and LepR-IR were detected and protein levels decreased significantly in high-fat-diets (HFD) rats than controls. The mRNA levels of kiss1, LepR and GnRH significantly decreased in the ARC of HFD-fed rats. No difference was observed in kiss1r mRNA levels between the two groups.ConclusionThese data suggest that failure to increase GnRH levels with HFD may be associated with pubertal down-regulation of LepR and kisspeptin/kiss1r system in the ARC of male rats.