低氧对高原鼠兔肝细胞内质网和心肌肌浆网Ca^2＋泵的影响

模拟高原低氧条件研究高原鼠兔肝细胞内质网（Ｅｎｄｏｐｌａｓｍｉｃｒｅｔｉｃｕｌｕｍ，ＥＲ）和心肌肌浆网（Ｓａｒｃｏｐｌａｓｍｉｃｒｅｔｉｃｕｌｕｍ，ＳＲ）钙泵功能变化。实验设对照组（海拔２３００ｍ）和两个低氧实验组（模拟海拔５０００ｍ和７０００ｍ）。２４ｈ急性低氧时，海拔５０００ｍ组高原鼠兔ＥＲ的Ｃａ２＋泵活性无变化，海拔７０００ｍ组高原鼠兔ＥＲＣａ２＋泵活性下降２９．０２％。７ｄ亚急性低氧时高原鼠兔ＳＲ的Ｃａ２＋泵活性无显著变化。高原鼠兔ＥＲ的Ｃａ２＋泵活性在海拔５０００ｍ组和７０００ｍ组分别升高３２．５０％和３３．３３％。２５ｄ慢性低氧时高原鼠兔ＥＲ，ＳＲ的Ｃａ２＋泵活性均无显著变化．表明：急性低氧对Ｃａ２＋泵功能有抑制作用，低氧７ｄ后抑制缓解，至２５ｄ低氧时趋于恢复。

THE EFFECTS OF STIMULATED HYPOXIA ON LIVER ENDOPLASMIC RETICULUM AND HEART SARCOPLASMIC RETICULUM Ca 2 PUMP OF OCHOTONA CURZONIAE

The effects of stimulated hypoxia on Ca 2 pump activity of the liver endoplasmic reticulum (ER) and heart scarcoplasmic reticulum (SR) of Ochotona curzoniae (pika) were studied. In this experiment Ochotona curzoniae were exposed to simulated altitudes of 5 000 m and 7 000 m in hypobaric pressure chamber for 24 hours,7 days and 25 days. The effects of different altitude and different duration of hypoxia on Ca 2 pump activity are not same. After exposed to 7 000 m hypoxia for 24 hours, Ca 2 pump activity of pika ER was inhibited 29 02%( P <0 01). After 7 days of hypoxia Ca 2 pump activity of ER and SR increase 32 59% ( P <0 05)and 33 33%( P <0 01) at altitude of 5 000 m and 7 000 m. During chronic hypoxia of 25 days, the Ca 2 pump activity of were unchanged.