Serum Metabolic Profiles in Chronic Intermittent Hypoxia Induced Rats

Six-week-old male Sprague-Dawley rats (170±2 g) were randomly assigned to two groups, each consisting of 5 rats, and housed in polycarbonate cages. Rats were provided with standard food and water and maintained on a 12-h light/dark cycle. The CIH group rats were exposed to intermittent hypoxia using plastic cages equipped with intermittent hypoxia devices for 8 h per day, with CIH being performed during the 12-h light cycle to align with the animals' sleep cycle. CIH rats were subjected to CIH for 28 consecutive days in 8-hour daily cycles from 9:00 am to 5:00 pm. During each cycle, the internal oxygen concentration was reduced from 21% to 8.5% over 4 min and maintained at this level for 2 min. The oxygen concentration was then rapidly restored to 21% for 2 min and maintained at this level for 1 min. Animals in the control group were housed in the same chamber but were provided with a constant flow of 21% oxygen. The serum samples collected from rats were stored at a temperature of –80 ℃.

6周龄雄性斯普拉格-道利（Sprague-Dawley）大鼠（体重170±2 g）随机分为两组，每组各5只，饲养于聚碳酸酯笼盒中。所有大鼠均饲喂标准饲料、饮用标准饮用水，并置于12小时光暗循环环境中饲养。慢性间歇性缺氧（Chronic Intermittent Hypoxia, CIH）组大鼠使用配备间歇性缺氧装置的塑料笼盒，每日暴露于缺氧环境8小时，且缺氧处理安排在12小时光照周期内，以匹配大鼠的睡眠节律。该组大鼠每日自上午9时至下午5时进行8小时间歇性缺氧处理，连续造模28天。单次缺氧循环中，笼内氧浓度于4分钟内从21%降至8.5%，并维持该浓度2分钟；随后快速恢复至21%，维持2分钟后再保持1分钟。对照组大鼠饲养于相同舱室，但持续通入流量稳定的21%氧气。采集的大鼠血清样本均保存于-80℃环境中。