摘要
目的:观测6周递增时间游泳训练及一次力竭运动后,大鼠骨骼肌SRCa2+转运能力相关指标的变化,为训练和/或力竭对骨骼肌SRCa2+转运活性影响的研究提供实验依据。方法:将大鼠随机分为安静组(S)、安静力竭组(SE)、训练组(T)和训练力竭(TE)组,训练组进行6周递增时间游泳训练,力竭组在6周后做一次力竭运动,检测相关指标。结果:训练大鼠游泳至力竭的时间明显长于未训练大鼠;训练组血清总睾酮(TT)含量降低40%(P<0.05),安静力竭组降低90%(P<0.01),训练力竭组降低94%(P<0.01);安静力竭组和训练力竭组大鼠血清肌酸激酶(CK)活性分别增加40%和100%;训练力竭组大鼠骨骼肌SR钙泵(Ca2+-ATPase)活性及SRCa2+摄取和释放显著增加,但SRCa2+释放/摄取的比值降低40%。训练力竭组大鼠腓肠肌2a型钙泵(SERCA2a)表达增强10%(P>0.05),而I型Ca2+释放通道(RyR1)表达减少30%(P<0.05),股四头肌钙调蛋白(CaM)增加(P<0.05),环一磷酸腺苷(cAMP)含量降低(P<0.05)。提示:尽管(过度)训练和力竭游泳增加SRCa2+摄取和释放,但损伤SRCa2+的相对释放能力,游泳时间越长越明显。这可能是Ca2+/CaM和cAMP依赖性信号通路上调SERCA/RyR1表达和SRCa2+转运的结果。股四头肌SRCa2+摄取和释放的幅度和速度大于腓肠肌。
The present study examined the effect of six- week time - increasing training and exhaustive swimming on calcium uptake and release in skeletal muscle sareoplasmic reticulum （SR） from Wistar rats. The rats were randomly invited into sedentary group（S）, sedentary with exhaustive swim group（SE）, training group （T）, and training with exhaustive swim group （TE）. A time - increasing swim training program for 6 weeks was used for the training groups, and an exhaustive swimming was subjected to the exhaustion groups at the end of 6 weeks. Whereafter the rats were killed and the parameters were measured. The trained rats showed a longer swimming time to exhaustion than the untrained （860 min vs 260 min, P 〈 0.001）. Serum total testosterone（TY） was reduced by 40%, 90%, and 94% in T （P 〈0.05）, SE （P 〈0.01）, and TE （P 〈0.01） rats respectively, compared with S group. Despite no difference between the SE and TE rats, exhaustive swimming induced 40% （P 〉 0.05） and 100% （P 〈 0.01） increases in serum creatine kinase （CK） activity, respectively. The results in skeletal muscle homogenates showed increases in SR Ca^2＋ pump （Ca^2＋ -ATPase）, SR Ca^2＋ uptake and release in SE, T, and TE rats （P 〈 0.05 -0.001）. However, -40% depressions in the ratio of SR Ca^2＋ release to uptake in T, SE, and TE rats were found, when comparing to S rats. Surprisingly the longer the swimming time to exhaustion was, the bigger the depression in the ratio. The expression of type 2a SR Ca^2＋ pump （SERCA2a） showed 10% elevation （P 〉 0.05）, while the expression of type Ⅰ Ca^2＋ release channel （type Ⅰ ryanodine receptor, RyR1 ） was reduced by 30 % in gastrocnemius of TE rats （ P 〈 0.05） . A significant increase in calmodulin （CaM） （P 〈 0.05 ） and a decrease in cyclic adenodine monophosphate （cAMP） （ P 〈 0.05） in quadriceps homogenates of TE rats, compared with S and T rats, were detected. The results suggest that although over- training and exhaustive swimming increase SR Ca^2＋ uptake and release, SR Ca^2＋ release capability relative to uptake was impaired. The longer the exhaustive swimming was, the more severe the impairment was. It may partly be attributed to the possible upregulation of Ca^2＋ / CaM- and cAMP- dependent signaling pathways on expression of SERCA/RyR1 and SR Ca^2＋ transport. Quadriceps showed a bigger and faster SR Ca^2＋ uptake and release than gastrocnemius.
出处
《中国运动医学杂志》
CAS
CSCD
北大核心
2005年第6期668-675,共8页
Chinese Journal of Sports Medicine
