中文摘要：

为了探讨高原鼢鼠和鼠兔的低氧适应机理，用紫外分光光度法测定了高原鼢鼠、鼠兔及大鼠心肌和骨骼肌乳酸脱氢酶（Lactate Dehydrogenase，LDH）的活力，通过聚丙烯酰胺凝胶电泳分离了LDH同工酶。结果显示：鼢鼠、鼠兔、大鼠心肌LDH活力分别为16．90±2．00U／mg pro，20．55±2．46U／mg pro，38．26±6．78U／mg pro，鼢鼠和鼠兔差异不显著（P〉0．05），大鼠与鼠兔差异显著（P〈0．05），大鼠与鼢鼠差异极显著（P〈0．01）；骨骼肌LDH活力，鼢鼠、鼠兔、大鼠分别为39．34±3．74U／mg pro，78．33±9．54U／mg pro，67．80±10．89U／mg pro，大鼠和鼠兔差异不显著（P〉0．05），二者均极显著高于鼢鼠（P〈0．01）。高原鼠兔与鼢鼠LDH同工酶M亚基的迁移率较为相近，而H亚基差别较大；鼢鼠和大鼠H亚基的迁移率较为相近，而M亚基差别较大。鼢鼠和鼠兔心肌LDH同工酶亚基组成以H亚基为主，M亚基含量较低，而骨骼肌LDH同工酶亚基组成以M亚基为主，H亚基含量较低。大鼠心肌和骨骼肌LDH同工酶H亚基和M亚基含量均很丰富。说明高原鼢鼠和鼠兔虽然生活在极其缺氧的环境中，但它们的组织并不缺氧；高原鼢鼠和鼠兔以不同的策略适应高原缺氧。

英文摘要：

In order to investigate the adapting mechanisms to altitudinal hypoxia of zokor and pika, the activity of LDH in heart muscle and skeletal muscle of plateau zokor, pika and Spragye-Dawley rat were determined by means of ultraviolet spectrophotometry, and the isozyme-spectra of LDH were analysed by means of polyacrylamide gel electrophoresis. The results indicated that： the activity of LDH in heart muscle of zokor, pika and rat were 16.90 ± 2.00 U/mg pro, 20.55 ±2.46 U/mg pro and 38.26 ±6.78 U/mg pro, respectively. There was no significant difference of the activity of LDH in heart muscle between zokor and pika, and they all significantly lower than that of rat. In skeletal muscle, the activity of LDH from zokor, pika and rat were 39.34 ± 3.74 U/mg pro, 78.33 ±9.54 U/rag pro and 67.80 ± 10.89 U/mg pro, respectively. Pika and rat were significantly higher than that of zokor, but there was no significant difference between each other. The electrophoretic mobility of M subunits from pika and zokor were ahnost the same, but varied in their H subunits; the electrophoretic mobility of H subunits from zokor and rat were almost the same, but varied in their M subunits. LDH in heart muscle of plateu zokor and pika had a high content of H subunits, but low content of M subunits, while it showed contrary resuits in skeletal muscle. LDH had a high content both of H subunits and M subunits in heart muscle of rat as well as skeletal muscle. It was concluded that although plateau zokor and pika lived in a hypoxia environment, their tissue had rich oxygen. Zokor and pika choose different strategy to adapt to the altitudinal hypoxia.