耐力训练后停训对大鼠骨骼肌肌浆网钙转运功能的影响

Influence of Transportation Function of Calcium ion in Sarcoplasmic Reticulum of Skeletal Muscle in Rat Detraining Models after Endurance Training

目的:观察大鼠耐力训练后停训对骨骼肌肌浆网钙转运功能的影响。方法:选用2月龄健康纯种雄性SD大鼠40只,随机分组即正常对照组(NC)8只、耐力训练组(TC)8只、耐力停训组(DT)24只。其中耐力训练组和耐力停训组的训练周期均为6周,6周训练后将耐力停训组根据停训的不同周期随机分为3组,即耐力停训2周组(DT1组),耐力停训4周组(DT2组),耐力停训6周组(DT3组)。采用动物跑台对实验对象进行递增负荷的耐力训练,达到耐力训练模型标准后,再采用不同周期的停训模型。使用全自动血细胞分析仪进行血液学指标的测定,采用酶偶联法对大鼠骨骼肌肌浆网Ca2+-ATP酶活性进行测定;荧光分光光度计对大鼠肌浆网最大Ca2+摄取量和释放量进行测定。结果:①骨骼肌肌浆网Ca2+-ATP酶活性和最大Ca2+摄取量:训练组较正常对照组显著增加(P<0.01);停训2周组与训练组比较变化不大(P>0.05);而停训4周、6周组与训练组相比较出现显著下降(P<0.01)。②骨骼肌肌浆网最大Ca2+释放量:训练组与正常对照组相比出现显著性增加(P<0.05);停训2周组与训练组比较差异不显著(P>0.05);而停训4周、6周组与训练组比较下降显著(P<0.01)。结论:经耐力训练6周后,大鼠骨骼肌肌浆网Ca2+-ATP酶活性增强,最大钙摄取及释放量出现增加。而停训2周时骨骼肌肌浆网Ca2+-ATP酶活性、最大钙摄取及释放量下降不显著。停训4周及更长时间骨骼肌肌浆网Ca2+-ATP酶活性及最大钙摄取及释放量下降显著。

Objective：To explore the changes of transportation function of calcium ion in sarcoplasmic reticulum of muscle in rat detraining model after endurance training.Methods： Forty healthy 2-month-old male SD were selected and randomly divided to normal control group（n=8）,training control group（n=8） and detraining group（n=24）.The increasing training period of training control group and detraining group lasted for 6 weeks,and then detraining group was randomly divided to 3 groups according to different detraining cycle： 2 weeks group（detraining 1 group）,4 weeks group（detraining 2 group） and 6 weeks group（detraining 3 group）.The rats did increasing endurance loading exercise on a treadmill,while difference detraining intervals was used in detraining group.Automatic blood cell analyzer was used to detect Hematology indexes.Enzyme coupling method and fluorescence probetechnology were used to detect sarcoplasmic reticulum Ca^2＋-ATPase（adenosine triphosphatase） and maximum Ca^2＋ uptake and release of gastrocnemius muscle.Results：The activity of Ca^2＋-ATPase and maximum uptake and release Ca^2＋ in training control group was significantly increased compared with normal control group（P〈0.01）;while detraining 2 weeks group was similar to endurance training group（P〉0.05）;detraining 4 and 6 weeks groups were significantly reduced compared with training control group（P〈0.01）.The maximum release Ca^2＋ in sarcoplasmic reticulum of muscle of training control grou was significantly increased（P〈0.05）,and there were no significant differences between detraining 2 weeks grou and training control group（P〉0.05）;while the maximum release of Ca^2＋ in sarcoplasmic reticulum of detraining 4 and 6 weeks group was significantly reduced（P〈0.01）.Conclusions： Six-week endurance training enhances activity of Ca^2＋-ATPase in sarcoplasmic reticulum of skeletal muscle and increases maximum Ca2＋ uptake and release;after detraining for 2 weeks,activity of Ca^2＋-ATPase,and maximum Ca^2＋ uptake and release are slightly reduced,while significantly reduced after more than 4 weeks of detraining.