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肉碱对运动训练大鼠骨骼肌线粒体呼吸链功能及氧自由基代谢的影响

李洁, 彭丽娜

西北师范大学体育学院，兰州 730070；廊坊师范学院，廊坊 065000

摘要

本研究旨在探讨肉碱对运动训练大鼠骨骼肌线粒体呼吸链功能及氧自由基代谢的影响。将雄性Wistar大鼠40只随机均分为4组(n = 10)：对照组、肉碱组、训练组和训练 + 肉碱组。训练和训练 + 肉碱组进行递增负荷水平跑台运动训练，肉碱组和训练 + 肉碱组每日灌胃口服肉碱(300 mg/kg)一次，每周6天，共处理6周。6周后各组大鼠均进行力竭运动，随后立刻取股四头肌样本，用差速离心法提取骨骼肌线粒体，测定线粒体呼吸链酶复合体I~IV (respiratory chain complexes I–IV, RCCI–IV)、超氧化物歧化酶(superoxide dismutase, SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase, GSH-Px)的活性及丙二醛(malondialdehyde, MDA)含量。结果显示，与对照组相比，肉碱组RCCI、RCCIII活性均显著升高(P < 0.05)，训练 + 肉碱组RCCI、RCCIII、RCCIV活性均显著升高(P < 0.05或P < 0.01)；与训练组相比，训练 + 肉碱组RCCIII活性显著升高(P < 0.05)。与对照组相比，肉碱组、训练组和训练 + 肉碱组SOD活性均显著升高(P < 0.01)，肉碱组和训练 + 肉碱组GSH-Px活性均显著升高(P < 0.01)，肉碱组、训练组、训练 + 肉碱组MDA含量均显著增加(P < 0.05或P < 0.01)。训练 + 肉碱组SOD、GSH-Px活性均显著高于训练组(P < 0.01)，MDA含量显著高于肉碱组和训练组(P < 0.01)。以上结果提示，运动训练及补充肉碱均可提高骨骼肌线粒体呼吸链功能、抗氧化能力和脂质过氧化耐受能力，且运动训练与肉碱具有协同效应。

关键词： 肉碱; 骨骼肌; 线粒体; 呼吸链; 氧自由基

分类号：G804.7

[Effects of carnitine on respiratory chain and metabolism of oxygen radical in mitochondria of skeletal muscle after exhaustive running in training rat.] [Article in Chinese]

LI Jie, PENG Li-Na

College of Physical Education, Northwest Normal University, Lanzhou 730070, China； Langfang Teachers College, Langfang 065000, China

Abstract

The aim of the present study was to investigate the effect of carnitine on function of respiratory chain and metabolism of oxygen radical in mitochondria of skeletal muscle after exhaustive running in training rats. Forty male Wistar rats were randomly divided into 4 groups (n = 10): control, carnitine, training and training + carnitine groups. The training and training + carnitine groups received 6-week treadmill training, whereas carnitine and training + carnitine groups were administered intragastrically with carnitine (300 mg/kg per day, 6 d/week) for 6 weeks. After exhaustive running, all the rats from 4 groups were sacrificed to obtain quadriceps muscles samples, and muscle mitochondria were extracted by differential centrifugation. Spectrophotometric analysis was used to evaluate activities of respiratory chain complexes (RCC) I-IV, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the content of malondialdehyde (MDA) in the skeletal muscle mitochondria. The results showed that, compared with the control group, the carnitine group exhibited increased RCCI and RCCIII activities (P < 0.05), the training + carnitine group exhibited increased RCCI, RCCIII and RCCIV activities (P < 0.05 or 0.01). Moreover, RCCIII activity in the training + carnitine group was higher than that in training group (P < 0.05). Compared with the control group, the carnitine, training and training + carnitine groups showed increased SOD activities ( P < 0.01), the carnitine and training + carnitine groups showed increased GSH-Px activities ( P < 0.01), the carnitine, training and training + carnitine groups showed increased MDA contents (P < 0.05 or 0.01). The SOD and GSH-Px activities in training + carnitine group were higher than those in training group (P < 0.01), and the MDA level in the training + carnitine group was higher than that in the carnitine and training groups (P < 0.01). These results suggest that training and carnitine can increase function of respiratory chain, antioxidation and lipid peroxidation tolerance capacity in skeletal muscle mitochondria, and the improving effects of training and carnitine are synergistic.

Key words: carnitine; skeletal muscle; mitochondria; respiratory chain; oxygen radical

收稿日期：2013-05-15　　录用日期：2013-08-29

通讯作者：李洁　　E-mail: lijie2005ty@126.com

引用本文：

李洁, 彭丽娜. 肉碱对运动训练大鼠骨骼肌线粒体呼吸链功能及氧自由基代谢的影响[J]. 生理学报 2013; 65 (6): 631-636.

LI Jie, PENG Li-Na. [Effects of carnitine on respiratory chain and metabolism of oxygen radical in mitochondria of skeletal muscle after exhaustive running in training rat.] [Article in Chinese]. Acta Physiol Sin 2013; 65 (6): 631-636 (in Chinese with English abstract).