ABSTRACT
Objective To compare the effect of aerobic and resistance exercise on brown adipose tissues in rats.Methods Sprague-Dawley rats were randomly assigned to a control(C)group,an aerobic exercise (T) group and a resistance exercise(L)group.The rats of group T performed treadmill exercise 5 days per week for 8 weeks,while those of group L climbed vertical ladders with progressively increased weights once in 3 days for 8 weeks.All rats were weighed before and after the intervention.Then the bilateral interscapular brown adipose tissue was isolated and weighed at 48h after the last exercise.The hematoxylin-eosin staining was used to observe the morphology of adipocytes,and the quantitative real-time PCR and Western blotting were employed to detect the mRNA and protein expression of browning genes [PR-domain-containing 16 (PRDM 16),PPAR gamma coactivator-1α (PGC-1 α) and uncoupling protein 1(UCP1)] respectively.Results After the intervention,the increment of weight of group T and group L were only 52％ and 70％ of group C(P＜0.01 and P＜0.05).The weight of BAT in both group T and L was lower than group C,but without significance(P＞0.05).The average size of lipid droplets in group T decreased significantly(P＜0.01) and slightly in group L(P＞0.05) compared with group C.The PRDM16,PGC-1α and UCP1 mRNA expression of group T was 1.78(P＜0.01),2.2(P＜ 0.01) and 1.3(P＞0.05) times of group C,while that of group L was 1.30(P＞0.05),1.25(P＞0.05) and 1.21(P＞0.05) times of group C.The PRDM16,PGC-1α and UCP1 protein level in group T was 1.46-fold(P＜0.05),1.56-fold(P＞0.05)and 1.20-fold(P＞0.05),while that of group L was 1.08-fold(P＞0.05),0.94-fold(P＞0.05) and 1.20-fold(P＞0.05) of group C.Conclusion Eight weeks of aerobic exercise can significantly make the lipid droplets of adipocyte smaller,increase the differentiation and metabolic activity of BAT,and weakly stimulate BAT thermogenesis.However,8 weeks of resistance exercise has no significant effect on BAT.
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Objective To explore the effect of aerobic exercise on Wnt/β-Catenin pathway in the cerebral cortex and hippocampus of rats,so as to provide theoretical basis for conforming that aerobic exercise can improve the function of the nervous system.Methods Six-week-old Sprague-Dawley male rats were randomly assigned to a sedentary control group (CG) and an aerobic exercise group (EG).The rats in the EG group underwent an 8-week treadmill training and their cerebral cortex and hippocampus were isolated at 48h after the last exercise.The mRNA levels of Wnt,β-Catenin,LRP5,LRP6,Axin1,CK1 and GSK3β were analyzed using quantitative PCR,while the protein and phosphorylation levels were assayed using Western blotting.Results After 8 weeks of treadmill exercise,the average mRNA and protein levels of Wnt1 and Wnt3 in the EG group were significantly higher than those in the CG group.Although there were no significant differences in β-Catenin mRNA levels between EG and CG groups,the protein levels of β-Catenin in the EG group were significantly higher than those in the CG group.Meanwhile,the phosphorylation levels of β-Catenin Ser33/Ser37 and Thr41/Ser45 were significantly lower than those in the CG group.In the EG group,the mRNA and protein levels of LRP5 and LRP6 were significantly higher than those in the CG group,while those of Axin1 and CK1 were significantly lower than the CG group.Moreover,no significant differences were observed in the mRNA and protein levels of GSK3β between the two groups,but the phosphorylation levels of GSK3β Ser9 in the EG group were significantly higher than the CG group.Conclusion Aerobic exercises can increase the levels of Wnt and Wnt receptor,protein LRP5 and LRP6,decrease the levels of Axin1 and CK1,inhibit the activity of GSK3β,altogether lowering the pbosphorylation of β-Catenin to promote the stableness of β-Catenin.Therefore,the aerobic exercise can increase Wnt/β-Catenin pathway activity and activate the downstream gene transcription in the cerebral cortex and hippocampus of rats.
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Objective To investigate the effects of aerobic exercise on tau phosphorylation and PI3K/ Akt pathway in the hippocampus of obese rats,and provide some theoretical basis for physical activity improving obesity-related neurological disorders.Methods Male Sprague-Dawley rats aged 3 weeks were randomly assigned to either a high-fat or a normal diet protocol for 12 weeks.Animals submitted to the high-fat diet were further divided into two groups:a sedentary group (HF-Sed) and an exercise group (HF-Ex).The rats fed the normal diet were also divided into a sedentary group (ND-Sed)and an exercise group (ND-Ex).The rats in the HF-Ex and ND-Ex groups underwent a treadmill training for 8 weeks.Then the hippocampus was isolated at 48h after the last exercise.The protein and phosphorylation levels of tau,glycogen synthase kinase 3β (GSK3β),phosphoinositide 3-kinase (PI3K) and Akt were assayed using Western blotting.Results After 12 weeks of feeding,55％ of rats in the high-fat diet group reached the conditions for the obesity model.After 8 weeks of treadmill exercises,in the HF-Sed group the phosphorylation level of tau was significanlty higher than that in the ND-Sed group,while in the HF-Ex group that was significantly lower than the HF-Sed group.Moreover,in the HF-Sed group the phosphorylation level of GSK3β Ser9 was significantly lower,and the phosphorylation level of GSK3β Tyr216 was significantly higher than the ND-Sed group,indicating the activity of GSK3β was significantly higher than the ND-Sed group.However,after 8 weeks of treadmill exercise,in the HF-Ex group the phosphorylation level of GSK3β Ser9 was signfiicantly higher,and the phosphorylation level of GSK3β Tyr216 was signficanlty lower than the HF-Sed group,indicating significantly lower activity of GSK3β than the HF-Sed group.Then,in the HF-Sed group the protein levels of PI3K p110 and p85 subunits,and the phosphorylation levels of Akt Thr308 and Ser473 were significantly lower than those in the ND-Sed group,indicating inhibited activity of the PI3K/Akt pathway.However,in the HF-Ex group the protein levels of PI3K p110 and p85 subunits and the phosphorylation levels of Akt Thr308 and Ser473 were significanlty higher than those in the HF-Sed group,showing the activity of PI3K/Akt pathway was enhanced.Conclusion Obesity induces tau hyperphosphorylation in the rats hippocampus and long-term aerobic exercises can reduce tau hyperphosphorylation by increasing PI3K/Akt pathway activity and inhibiting GSK3β activity.It has a positive effect on delaying the formation of neurofibrillary tangles and improving obesity-related neurological disorders.
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Objective To observe the effect of 8-week climbing ladder exercise with load on the expression of proliferator-activated receptor gamma coactivator 1-alpha (PGC1α)/ fibronectin type Ⅲ domain containing 5 (FNDC5)/ myostatin (MSTN)in soleus and extensor digitorum longus muscle and the serum concentration of irisin in Sprague-Dawley (SD)rats.Methods Twenty SD rats were randomly divided into a control (Con,n=10)group and a climbing ladder (Lad,n=10)group.The Lad group took an 8-week and once-every-3-day program of resistance exercise using an improved model of climbing ladder with load.Then the soleus and extensor digitorum longus muscles were isolated at 48 h after exercise.The PGC1α/FNDC5/MSTN mRNA and protein expression in the skeleton muscle were detected using quantitative PCR and Western blotting respectively.The serum concentration of irisin was measured using enzyme-linked immunosorbent assay.Results Compared with Con group,the expression of PGC1α in the soleus muscle reduced significantly (P＜0.05),that of FNDC5 reduced but without significance and that of MSTN increased significantly (P＜0.05)in Lad group.However,the expression of PGC1α in the extensor digitorum longus muscle increased significantly (P＜0.05),that of FNDC5 increased but without significance and that of MSTN decreased significantly (P＜0.05)in Lad group compared with Con group.There were no significant differences in the serum concentration of irisin between the two groups.Conclusion Eight-week climbing ladder exercise with load on rats induces differential expression of PGC1α/FNDC5/MSTN in soleus and extensor digitorum longus muscle,but doesn't influence the serum concentration of irisin.It is suggested that there may be a complex mechanism of balancing and antagonism in the body after long-term resistance exercises.
ABSTRACT
Objective To improve the resistance exercise apparatus of climbing ladder with load on rats, and to observe the technological, athletic training and biological response to the improved experimental apparatus.Methods Thirty-six healthy SPF male Sprague-Dawley were randomly divided into control and exercise groups.The climbing ladder and weight bearing device were separately improved to develop a new resistance exercise apparatus of climbing ladder with load on rats.The exercise group took an 8-week incremental exercise program using this improved device.To observe the operation effect of this improved exercise apparatus.To observe the dynamic changes of average maximum load on SD rats from the exercise group during 8 weeks.To compare the effect of climbing ladder exercise with load on body weights of SD rats between the two groups.Results The improved climbing ladder was marked by the prioritization technique of architecture stabilization, weight bearing and easy cleaning.The improved bearing device has the advantages of being sturdy and durable, and simplemethod to calculating load.Moreover, the new experimental apparatus can be operated by one person during the exercise program.The average maximum load was successfully increased to 756 g after an 8-week exercise using the improved apparatus.Compared with the control group, the body weights of SD rats from the exercise group after training were significantly reduced (P<0.05).Conclusions The improved resistance exercise apparatus of climbing ladder with load can provide a more endurable and repeatable process in the study of rat strength training and it is recommended to use this new device in future experimental research.