有氧运动对肥胖小鼠胃组织Ghrelin和下丘脑GHSR-1a表达的影响

The Effect of Aerobic Exercise on the Expression of Ghrelin in the Gastric Tissue and GHSR-1a in the Hypothalamic Tissue of Obese Mice

目的:探讨有氧运动对肥胖小鼠胃组织Ghrelin-下丘脑组织GHSR通路相关基因表达的影响,明确运动改善胃功能以抵抗肥胖的可能机制。方法:雄性C57BL/6J小鼠40只随机分为普通对照组(NC组,n=8),饲喂普通饲料;高脂膳食组(H组,n=32),饲喂高脂饲料8周以建立肥胖模型。建模成功后的小鼠随机分为高脂对照组(HC组,n=8)和高脂运动组(HE组,n=8),均继续饲喂高脂饲料,同时HE组进行速度12 m/min、1 h/次/天、6次/周的4周跑台训练。结束后取血清、胃和下丘脑组织。测试血清甘油三酯(TG)、总胆固醇(CHO)、血糖(GLU)和总Ghrelin水平;RT-PCR和Western blotting测试胃组织Ghrelin、Goat和下丘脑GHSR-1a mRNA和蛋白表达水平。结果:(1)运动干预后,HE组体重较HC组降低(P<0.05);运动干预2周后,HE组每周摄食量较HC组下降,但运动4周后又趋于接近。(2)HC组血脂血糖各指标均高于NC组(P<0.05),HE组GLU水平较HC组下降(P<0.05)。(3)在胃组织,HC组Ghrelin和Goat mRNA水平与NC组相比下降(P<0.01),HE组Ghrelin mRNA(P<0.01)和蛋白水平(P<0.05)、Goat m RNA和蛋白水平(P<0.05)高于HC组。(4)在下丘脑,HC组GHSR-1αm RNA水平较NC组下降(P<0.01),HE组GHSR-1a蛋白水平较HC组升高(P<0.05)。结论:有氧运动可能通过上调肥胖小鼠胃组织Ghrelin-下丘脑GHSR信号通路而改善血脂血糖水平以抵抗肥胖。

Objective To investigate the effect of aerobic exercise on the expression of genes related to the Ghrelin-growth hormone secretagogue receptor(GHSR)pathway of obese mice,and to clarify the possible mechanism of exercise resisting obesity by improving the gastric tissue function.Methods Forty C57 BL/6 J male mice were randomly divided into a control group(NC,n=8,fed with normal diet)and a high fat diet group(H,n=32,fed with high fat diet).After 8 weeks,the obese mice of the H group were further divided into a high-fat diet control group(HC,n=8)and a high-fat diet exercise group(HE,n=8),and the HE group underwent a one-hour treadmill training six times a week at a speed of 12 m/min for 4 weeks.After 4 weeks of intervention,the serum triglyceride(TG),cholesterol(CHO)and glucose(GLU)levels were detected using the biomedical analyzer,and the total Ghrelin level was measured using the enzyme-linked immunosorbent assay.The mRNA and proteins expression of Ghrelin and Ghrelin O-acyltransferase(Goat)in the gastric tissue and GHSR-1 a in the hypothalamic tissue were detected using the reverse transcription-polymerase chain reaction and Western blotting.Results(1)After 4 weeks of exercise intervention,the weight of the HE group was significantly lower than the HC group(P<0.05).The weekly food intake of group HE decreased compared with group HC after 2 weeks of exercise intervention,but became nearly the same after 4-week exercise.(2)The CHO and TG levels of the HC group were significantly higher than the NC group(P<0.05),and the GLU levels of group HE was significantly lower than group HC(P<0.05).(3)The Ghrelin and Goat mRNA level in the gastric tissue of the HC group was significantly lower than the NC group(P<0.01).However,the average Ghrelin mRNA(P<0.01)and protein levels(P<0.05),Goat m RNA and protein expression level(P<0.05)of group HE were significantly higher than group HC.(4)In the hypothalamic tissue,the GHSR-1 a m RNA level of the HC group was significantly lower than group NC(P<0.01),while the GHSR-1 a protein expression of the former was significantly lower than the HE group(P<0.05).Conclusion Aerobic exercise may improve blood lipid and blood glucose levels to resist obesity by up-regulating the expressions of Ghrelin the in gastric tissue-GHSR in the hypothalamic tissue of high-fat diet mice.