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[Difference in oxygen uptake in skeletal muscles between plateau zokor (Myospalax rufescens baileyi) and plateau pika (Ochotona curzoniac).] [Ariticle in Chinese]

ZHU Shi-Hai, QI Xin-Zhang, WANG Xiao-Jun, RAO Xin-Feng, WEI Lian, WEI Deng-Bang^*

Department of Biology, Qinghai University, Xining 810016, China

Abstract

To investigate the difference between the functions of oxygen uptake in skeletal muscle and living habits of plateau zokor (Myospalax rufescens baileyi) and plateau pika (Ochotona curzoniac), the microvessel densities (MVD) of skeletal muscle of plateau zokor, plateau pika and Sprague-Dawley (SD) rat were measured by immunohistochemical staining; the numerical density on area (NA) of mitochondria, and surface density (SV, external surface area density of mitochondria per unit volume of skeletal muscle fiber) were obtained by stereo microscope technique; mRNA levels of myoglobin (Mb) in skeletal muscle were determined by real-time PCR, and the contents of Mb protein in skeletal muscle were determined by spectro-photometer. The results showed that MVD, NA and SV of mitochondria in skeletal muscle of plateau pika were significantly lower than those of plateau zokor and SD rat (P<0.05). The mRNA levels of Mb gene in skeletal muscle of plateau zokor and plateau pika were notably higher than that of SD rat (P<0.05). There were significant differences in the contents of Mb among these three species, and plateau zokor and SD rat presented the highest and the lowest value, respectively (P<0.05). The results suggest that even though plateau zokor inhabits in the hypoxia environment, most of its skeletal muscle fiber are red muscle fiber. While most of skeletal muscle fibers of plateau pika are white muscle fibers. This kind of white muscle has low MVD, NA and SV of mitochondria and less content of Mb compared with the red one, suggesting it obtains most energy from aerobic oxidation. The above-mentioned differences in skeletal muscles may be related to not only the different species, but also the different living habits of these two high altitude species.

Key words: plateau zokor (Myospalax rufescens baileyi); plateau pika (Ochotona curzoniac); hypoxia; skeletal muscle

Received: 2008-12-11　　Accepted: 2009-06-16

Corresponding author: 魏登邦　　E-mail: weidengbang@163.com

Citing This Article：

ZHU Shi-Hai, QI Xin-Zhang, WANG Xiao-Jun, RAO Xin-Feng, WEI Lian, WEI Deng-Bang. [Difference in oxygen uptake in skeletal muscles between plateau zokor (Myospalax rufescens baileyi) and plateau pika (Ochotona curzoniac).] [Ariticle in Chinese] . Acta Physiol Sin 2009; 61 (4): 373-378 (in Chinese with English abstract).