中文摘要：

目的探讨高原低氧对N-乙酰基转移酶Ⅱ（NAT2）活性的影响。方法以AFMU/（AFMU＋1U＋1X）的比率评价N-乙酰基转移酶2（NAT2）的活性。大鼠随机分为低海拔对照组、急性缺氧1、3、7天组和慢性缺氧组共五组,分别灌胃予探针药物咖啡因。采用HPLC方法,测定大鼠予咖啡因后尿液中代谢产物5-乙酰氨基-6-甲酰氨基-3-甲基嘧啶（AFMU）、1-甲基尿酸（1U）、1-甲基黄嘌呤（1X）水平。结果缺氧可导致大鼠NAT2活性降低,尤其急性缺氧3天时降低程度最大,可达38.7%。结论高原低氧能明显降低大鼠NAT2活性。

英文摘要：

Objective To study the effect of high altitude hypoxia on the activity of NAT2 in rat. Methods The activity of N - acetyhransferase （ NAT2 ） by calculating the rate of AFMU/（ AFMU ＋ 1 U ＋ 1X）. After rats were ran- domly divided into low altitude（L） ,1 day after acute exposure to high altitude（ HA1 ） ,3 days after acute exposure to high altitude （ HA3）, 7 days after acute exposure to high altitude （ HA7 ） and chronic exposure to high altitude （HC）. They were administrated orally caffeine, determining three metabolites 5 - acetylamino - 6 - formylamino - 3 - methyluracil （ AFMU）, 1 - methylurie acid （ 1 U） and 1 - methylxanthine （ 1 X） of caffeine in Rats urine by HPLC. Results hypoxia reduces the activity of NAT2 of rat, especially 3 days after acute exposure to high altitude, the level of reduction was reached about 38.7%. Conclusion The activity of NAT2 in rat is obviously reduced by high alti- tude hypoxia.