Mechanism of Exercise and Diet Interventions on Central Posterior Receptor Signaling of Leptin Resistance Rats

Objective:To observe the effect of exercise and diet interventions on central posterior receptor signaling of leptin resistance obese rats in order to study the effect of SOCS3 on leptin resistance.Method:Totally 130 SD male rats were randomly divided into control group(n=10) and model group(n=120).Two groups were fed with common rodent animal feed and high fat diet respectively.After 8 weeks,we selected 1/3 body weight rats ahead in model group,then measure the serum leptin.The model group rats(n=40) were randomized into four groups:high fat diet group(H16),high fat diet and exercise group(HHE),common diet and exercise group(HNE),common diet group(HN).The control group was recorded as N16.Each group rats were given meal intervention or had medium intensity treadmill exercise for 8 weeks.The serum leptin was measured by ELISA.SOCS3,in hypothalamus was observed by Western blot.SOCS3 mRNA in hypothalamus was showed by real time fluorescent quantitation PCR.Result:1) Leptin of HNE,HHE groups were lower than that of H16(P<0.05),and leptin of HNE group was significantly lower than those of HHE,HN groups(P<0.01).2)LP-Rb in hypothalamus of H16 group was lower than that of N16 group(P<0.05);those of HNE,HHE group significantly elevated compared with H16 group(P<0.05);those of HHE,HN groups were lower than that of HNE group(P<0.05).LP-Rb in hypothalamus had weaker negative correlation with leptin,r=-0.286,(P<0.05).3) p-STAT3/STAT3 of HNE,HHE groups elevated because of exercise and diet interventions,compared with H16 group(P<0.05).4) SOCS3 mRNA of each group had no difference(P>0.05).SOCS3 of HNE,HHE group was significantly lower than that of H16(P<0.05),SOCS3 of HNE was lower than that of N16 group(P<0.05).SOCS3 of HHE,HN group was significantly higher than that of HNE(P<0.01).SOCS3 in hypothalamus had low correlation with serum leptin,R=0.338,(P<0.05).Conclusions:Exercise combination with diet invention was better than exercise or diet to improve central leptin resistance,which mechanisms were possible related to following factors:Leptin lowering,LP-Rb in hypothalamus rising.P-STAT in hypothalamus rising.SOCS3 in hypothalamus lowered.