间歇缺氧对幼龄大鼠血清中胰岛素样生长因子水平的影响

Study on intermittent hypoxia in children sleep apnea hypopnea syndrome model and insulin-likegrowth factor-1 and insulin-like growth factor binding protein-3 levels in serum

目的利用间歇缺氧条件下饲养的幼龄大鼠研究间歇缺氧与生长发育迟滞的关系。方法设计制造自动控制环境低氧装置，实现可控的间歇低氧。选取24只25日龄雌性SD大鼠，随机均分为对照组及轻、重度缺氧组。对照组正常喂养；其他两组饲养于间歇低氧箱内，每天循环间歇缺氧8h，共35d。根据预实验的结果确定间歇低氧的浓度和频度，使轻度组动物每小时发生低氧事件6次，平均最低血氧饱和度降至0．853；重度组动物每小时发生低氧事件24次，平均最低血氧饱和度降至0．776。实验前后均测量体质量及身长，并取静脉血用酶联免疫吸附测定法检测血清胰岛素样生长因子（insulin-likegrowthfactor，IGF）-1及胰岛素样生长因子结合蛋白（insulin-like growth factorbinding protein，IGFBP）-3表达水平。结果3组大鼠实验前后身长和体质量差异均无统计学意义（P值均〉0．05）。实验前各组血清IGF-1和IGFBP-3水平差异无统计学意义（P值均〉0．05），实验35d后，对照组、轻度缺氧组和重度缺氧组血清中IGF-1（元±s，下同）分别为（60．0±18．5）ng／ml、（40．6±9．9）ng／ml和（13．1±8．6）ng／ml，F=25．840，P〈0．01；IGFBP-3分别为（1．93-4-0．23）μg／ml、（1．39±0．30）μg/m1和（0．90-t-O．21）μg/ml，F=33．929，P〈0．01；差异均有统计学意义，且IGF-1及IGFBP-3水平随着缺氧程度加重而降低（P值均〈0．05）。结论模拟儿童睡眠呼吸暂停低通气综合征缺氧程度的间歇缺氧幼龄大鼠模型尚未引起大鼠体格发育迟缓，但造成大鼠血清中IGF-1、IGFBP-3水平下降并随着缺氧程度加重及血氧饱和度降低而降低。

Objective Using rats fed in intermittent hypoxia environment to study the relationship between sleep apnea hypopnea syndrome （ SAHS ） of children and growth retardation. Methods The hypoxie chamber was designed and manufactured, the control of intermittent hypoxia was achieved. Twenty- four rats were randomly divided into three groups： mild and severe hypoxia group, and control group. In control group, the animals were normally fed, without interruption. The animals in other two groups were kept in the cabin, simulated mild and severe intermittent hypoxia conditions 8-hour a day, a total of 35 days. According to the results of preliminary experiments, the concentration of intermittent hypoxia and frequency were determined. The animals with mild hypoxia events occurred nearly six times per hour, the average minimum oxygen saturation dropped to 0. 853, the animals with severe hypoxia events occurred nearly 24 times per hour, the average minimum oxygen saturation dropped to 0. 776. Body mass and length were measured before and after experiment. The serum insulin-like growth factor （IGF） -1 and insulin-like growth factor binding protein （IGFBP）-3 expression were tested from venous blood by enzyme-linked immunosorbent assay （ELISA）. Results The length and body mass of rats in three groups before and after experiment were not statistically different （P 〉 0. 05 ）. Before the experiment the serum IGF-1 and IGFBP-3 levels were not significantly different（P 〉 0. 05）. 35 d after the experiment, the serum IGF-1 （x±s, the same below） inthe control group, mihl hypoxia and severe hypoxia were （60. 0± 18.5 ）ng/ml, （40. 6 ±9. 9）ng/ml and （ 13.1± 8.6） ng/ml. F = 25. 840. P 〈 0. 01 ; the serum IGFBP-3 were （ 1.93 ± 0. 23） μg/ml, （ 1.39± 0. 30） ~g/ml and （0. 90± 0. 21 ） tzg/ml, F = 33. 929, P 〈 0.01. The differences were statistically significant. The 1GF-1 and I（,FBP-3 levels decreased as the hypnxia increased （P 〈 0. 05 ）. Conclusion In simulated sleep apnea hypopnea syndrome, the intermittent hypoxia in young rats does not show physical growth retardation, hut the serum IGF-1 , IGFBP-3 levels decreased with the increase of hypoxia and decline of oxygen saturation.