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[Effects of acute hypobaric hypoxia and exhaustive exercise on AMP-activated protein kinase phosphorylation in rat skeletal muscle.] [Article in Chinese]

YANG Tao, HUANG Qing-Yuan^*, SHAN Fa-Bo, GUAN Li-Bin, CAI Ming-Chun

Department of Pathophysiology and High Altitude Physiology, College of High Altitude Military Medicine, the Third Military Medical University, Key Laboratory of High Altitude Medicine of Ministry of Education, the Key Laboratory of High Altitude Medicine of PLA, Chongqing 400038, China

Abstract

The present study was aimed to explore the changes of phosphorylated AMP-activated protein kinase (pAMPK) level in skeletal muscle after exposure to acute hypobaric hypoxia and exhaustive exercise. Thirty-two male Sprague-Dawley (SD) rats were randomly divided into sea level and high altitude groups. The rats in high altitude group were submitted to simulated 5 000 m of high altitude in a hypobaric chamber for 24 h, and sea level group was maintained at normal conditions. All the rats were subjected to exhaustive swimming exercise. The exhaustion time was recorded. Before and after the exercise, blood lactate and glycogen content in skeletal muscle were determined; AMPK and pAMPK levels in skeletal muscle were detected by Western blot. The results showed that the exhaustion time was significantly decreased after exposure to high altitude. At the moment of exhaustion, high altitude group had lower blood lactate concentration and higher surplus glycogen content in gastrocnemius compared with sea level group. Exhaustive exercise significantly increased the pAMPK/AMPK ratio in rat skeletal muscles from both sea level and high altitude groups. However, high altitude group showed lower pAMPK/AMPK ratio after exhaustion compared to sea level group. These results suggest that, after exposure to acute hypobaric hypoxia, the decrement in exercise capacity may not be due to running out of glycogen, accumulation of lactate or disturbance in energy status in skeletal muscle.

Key words: Hypoxia; exercise; AMP-activated protein kinase; skeletal muscle; glycogen

Received: 2011-10-08　　Accepted: 2011-11-29

Corresponding author: 黄庆愿　　E-mail: qyhuangwu@yahoo.com.cn

Citing This Article：

YANG Tao, HUANG Qing-Yuan, SHAN Fa-Bo, GUAN Li-Bin, CAI Ming-Chun. [Effects of acute hypobaric hypoxia and exhaustive exercise on AMP-activated protein kinase phosphorylation in rat skeletal muscle.] [Article in Chinese]. Acta Physiol Sin 2012; 64 (2): 193-198 (in Chinese with English abstract).