The Effect Of Exercise Mode On The Hypothalamic Expression Of Kiss-1and Gpr54 Genes Mrna In Dietinduced Obesity Rats

Abstract

Kisspeptin, a hypothalamic peptide coded by the KiSS1 gene, is a neuromodulator that controls GnRH secretion and is now recognized as a crucial regulator of the onset of puberty. PURPOSE: To explore the difference roles of moderate-intensity treadmill training (MIT) and high intensity interval treadmill training (HIIT) in modulating the hypothalamic expression of KiSS-1and the G-protein coupled receptor (GPR) 54 mRNA in the diet induced obesity male rats. METHODS: After 8 weeks high fat feeding, 24 obesity 11-weeks SD rats were randomly assigned to sedentary (FS, n=8), MIT (n=8) , and HIIT (n=8) groups, 8 normal diet 11-weeks SD rats were assigned as sedentary (SS, n=8) groups. During the following 8 weeks, obesity rats were continued expose to high-fat-diet. MITgroup did the 60%-70%V(•)O2max treadmill training (5 days/week, 1 hour/day). HIIT group did the HIIT training (5 days/week, 1 hour/day),which included 7 minutes warmup (70% V(•)O2max), 6groups formal training(90% V(•)O2max*3min+ 50% V(•)O2max*3min) and 7 minutes recobery (70% V(•)O2max) The V(•)O2 max of exercise groups were remeasured every two weeks. The hypothalamic expression of KiSS-1 and GPR54 mRNA were tested in each group. RESULTS: After the first 8-weeks high fat feeding, the obesity rats were heavier than normal diet group (491.74±26.19g vs. 410.05±45.77g, p<0.01). After 8-weeks training, FS group was still heavier than SS group (681±52.56g vs. 574.27±52.43g, p<0.01), and had more hypothalamic expression of KiSS-1 mRNA(1.51±0.66 vs 0.75±0.27, p<0.05) and GPR54 mRNA (2.45±0.38 vs 0.61±0.15, p<0.01). Both MIT and HIIT groups weighted less than FS group, HIIT group had the lightest bodyweight (590.23±35.74g, 558.1±29.57g vs 681±52.56g). Compared with FS group, although both MIT and HIIT groups had lower hypothalamic expression of KiSS-1 mRNA and GPR54 mRNA, HIIT group had the lowest hypothalamic expression of KiSS-1 mRNA (0.47±0.13 vs 0.69±0.13, p<0.01) and GPR54 mRNA(0.58±0.10 vs 0.23±0.06, p<0.01). CONCLUSIONS: Both MIT and HIIT could reduce the stimulating effect of high-fat diet induced obesity on bodywight and hypothalamic expression of KiSS-1and GPR54 mRNA, and HIIT could play a better role.