Effects Of8Weeks Exercise On The Hypothalamic Leptin-Kisspeptin-GnRH Pathway In Rats With Different Conditions Of Insulin Resistance

Objective:Insulin resistance can cause hypotestosteronemia and reproductive dysfunction in men. Whileexercise is recognized as one of the most effective ways to improve the insulin resistance, butwhether exercise can improve insulin resistance effects on hypotestosteronemia is unclear. Thisresearch explored the effect of long-term aerobic exercise on different conditions of insulinresistance male rats serum testosterone and central regulatory mechanism, it designed to provideexperimental basis of clarifying the effect on long-term aerobic exercise in improving itshypotestosteronemia by insulin resistance, and to provide theoretical basis for exploring waysand means of prevention.Methods:Divide40pcs10months-age of SD male rats for the study, selected6pcs randomly as thenormal diet control group, the remaining34pcs to high-fat diet group,8weeks after modelinghigh-fat diet obesity, randomly divided into four groups according to body weight, obesitycontrol group, obesity exercise group, diabetes control group, diabetes exercise group,8pcs ineach group. Diabetes control group and diabetes exercise group, intraperitoneal injection lowdose of STZ to induce type2diabetes. Obesity exercise group and diabetes exercise groupperformed swimming training for8weeks. After training, using spectrophotometry,radioimmunoassay, Real-time PCR and Western-blot methods to determine blood parameters andthe genetic transcription and protein expression levels for the index of correlation ofleptin-kisspeptin-GnRH in the hypothalamus.Results:1.Compared to normal control group rats, weight, lipid ratio, fat weight, serum TC, TG, FFA,LDL-C level in obesity control group raised significantly（P＜0.01、P＜0.01、P＜0.05、P＜0.05、P＜0.01、P＜0.01、P＜0.05）; and compared to normal control group rats, weight, lipid ratio, fatweight in diabetes control group rats didn’t appeared significantly(P>0.05), but serum TC, TG,FFA, LDL-C level raised significantly（P＜0.01、P＜0.01、P＜0.01、P＜0.05）; compared obesityexercise group rats to obesity control group rats, weight, lipid ratio, fat weight, serum TC, TG,FFA, LDL-C level reduced significantly(P＜0.01、P＜0.01、P＜0.01、P＜0.05、P＜0.01、P＜0.01、P＜0.05); compared diabetes control group to diabetes exercise group, weight, lipid ratioand fat weight are just the same(P>0.05), but serum TC, TG, FFA, LDL-C level reducedsignificantly(P<0.05). 2.Compared to normal control group rats, blood sugar, serum insulin and serum leptin level inobesity control group raised significantly(P＜0.05、P＜0.01、P＜0.01), serum testosteronereduced significantly(P<0.05); and compared to normal control group rats, blood sugar, seruminsulin and serum leptin level in obesity control group raised significantly(P＜0.01、P＜0.01、P＜0.05), serum testosterone reduced significantly(P<0.01). Compared obesity exercise group ratsto obesity control group rats, blood sugar, serum insulin and serum leptin level reducedsignificantly(P＜0.05、P＜0.01、P＜0.05), serum testosterone raised significantly(P<0.05);compared diabetes control group to diabetes exercise group, blood sugar, serum insulin andserum leptin level reduced significantly(P<0.05), serum testosterone raisedsignificantly(P<0.01).3.Compared to normal control group rats, regardless obesity control group or diabetes controlgroup, hypothalamus leptin receptor, kisspeptin and GnRH mRNA(P<0.01) and proteinexpression(P＜0.01、P＜0.01、P＜0.05) declined significantly. Compared obesity exercise groupto obesity control group rats, hypothalamus leptin receptor, kisspeptin and GnRH mRNA(P<0.01)and protein expression raised significantly(P<0.05). Compared diabetes exercise group todiabetes control group rats, hypothalamus leptin receptor, kisspeptin and GnRH mRNA(P<0.01)and protein expression increased significantly(P<0.05、P<0.01、P<0.05).Conclusion:1.Obesity rats and type2diabetes rats not only glucose and lipid metabolic disorders, but alsocaused a hypotestosteronemia, speculated that hypothalamic leptin-kisspeptin-GnRH pathwaygene transcription and protein expression levels of damage is one of the mechanisms whichcaused erum testosterone reduced.2.Long-term aerobic exercise interventions can increse the level of erum testosterone, alleviatelow testosterone levels by improving the damaged gene transcription and protein expression inhypothalamic leptin-kisspeptin-GnRH pathway significantly.