Xu Yu-Ming, Li Jun-Ping, Wang Rui-Yuan
College of Education, Zhejiang University, Hangzhou 310028, China.
Sheng Li Xue Bao. 2012 Aug 25;64(4):455-62.
The aim of the present study was to explore the changes and roles of dystrophin and membrane permeability in hypoxic training. Seventy-two 8-week-old Sprague Dawley (SD) rats were randomly divided into 4 groups, normoxic non-train (NC), normoxic train (NT), hypoxic non-train (HC), and hypoxic train (HT) groups. The rats of each group were randomly divided into three subgroups, non-exhaustive, low-speed exhaustive test and high-speed exhaustive test subgroups. Rats in hypoxia groups lived and were trained in a condition of 12.7% oxygen concentration (equal to the 4 300 m altitude). NT and HT groups received 4 weeks of training exercise. Then the rats in all non-exhaustive subgroups were sacrificed, and gastrocnemii were sampled for the measurements of lactate dehydrogenase (LDH), succinatedehydrogenase (SDH), malate dehydrogenase (MDH) activities. Moreover, serum LDH activity was analyzed. Low-speed exhaustive test and high-speed exhaustive test subgroups received exhaustive tests with 20 (71% VO2max) and 30 m/min speed (86% VO2max), respectively, and their exhaustive times were recorded. The results showed that, compared with normoxic groups, the weights in hypoxia groups exhibited slower increase. The level of dystrophin in HT group without exhaustion test didn't change significantly. The muscle MDH activities were markedly affected by the different oxygen concentration, training and their interaction (P < 0.05), whereas the muscle LDH activities were only affected by the different oxygen concentration (P < 0.05). Serum LDH activities were affected by the interaction of the different oxygen concentration and training (P < 0.05), showing decreased muscle LDH and increased blood LDH activities. The exhaustion time were markedly affected by the different test speed, training and their interaction (P < 0.05), and also affected by the interaction of the different oxygen concentration and training (P < 0.05), but didn't affected by oxygen concentration. The exhaustive time of HT high-speed exhaustive test subgroup was more than NT high-speed exhaustive test subgroup in 30 m/min exhaustion test. Compared with NT high-speed exhaustive test subgroup, HT high-speed exhaustive test subgroup had an earlier fatigue in the test, but had a rapid recovery. These results suggested that hypoxic training can effectively increase the rats' high-speed exhaustive time. The mechanism may be related to an increase in serum LDH caused by the increased membrane permeability after hypoxic training.
本研究的目的是探讨抗肌萎缩蛋白和膜通透性在低氧训练中的变化及作用。将72只8周龄的Sprague Dawley（SD）大鼠随机分为4组，即常氧不训练组（NC）、常氧训练组（NT）、低氧不训练组（HC）和低氧训练组（HT）。每组大鼠再随机分为三个亚组，即非力竭组、低速力竭试验组和高速力竭试验组。低氧组大鼠在氧浓度为12.7%（相当于海拔4300米）的条件下生活和训练。NT组和HT组进行4周的训练运动。然后处死所有非力竭亚组的大鼠，取腓肠肌样本测量乳酸脱氢酶（LDH）、琥珀酸脱氢酶（SDH）、苹果酸脱氢酶（MDH）活性。此外，分析血清LDH活性。低速力竭试验组和高速力竭试验组分别以20米/分钟（71%最大摄氧量）和30米/分钟（86%最大摄氧量）的速度进行力竭试验，并记录其力竭时间。结果显示，与常氧组相比，低氧组大鼠体重增加较慢。未进行力竭试验的HT组抗肌萎缩蛋白水平无明显变化。肌肉MDH活性受不同氧浓度、训练及其交互作用的显著影响（P<0.05），而肌肉LDH活性仅受不同氧浓度的影响（P<0.05）。血清LDH活性受不同氧浓度和训练交互作用的影响（P<0.05），表现为肌肉LDH降低，血液LDH活性升高。力竭时间受不同试验速度、训练及其交互作用的显著影响（P<0.05），也受不同氧浓度和训练交互作用的影响（P<0.05），但不受氧浓度影响。在30米/分钟的力竭试验中，HT组高速力竭试验亚组的力竭时间比NT组高速力竭试验亚组长。与NT组高速力竭试验亚组相比，HT组高速力竭试验亚组在试验中疲劳较早，但恢复较快。这些结果表明，低氧训练可有效增加大鼠的高速力竭时间。其机制可能与低氧训练后膜通透性增加导致血清LDH升高有关。
