模拟高原慢性缺氧环境下便携式氧气机富氧对大鼠行为学的影响

Effects of oxygen-enriched atmospheres provided by portable oxygen-enriched machine on the behaviors of rats in a simulated chronic hypoxic environment

目的:探索模拟高原慢性缺氧环境下便携式氧气机富氧对大鼠行为学的影响。方法:利用低压舱模拟海拔5 000 m高原缺氧环境,利用自主研制的便携式膜法氧气机与大鼠IVC笼盒建立富氧饲养笼。将36只雄性SD大鼠随机分为平原对照组(NC)、缺氧组(HH)与富氧组(HO),HH与HO组置于低压舱内饲养4周(22 h/d),HO组每天有效富氧8h,NC组于舱外同时饲养。实验前及实验后每周监测大鼠体质量,饲养4周后测量各组大鼠行为学指标及皮肤平均血流灌注量数据,进行统计学分析。结果:实验前各组大鼠体质量差异无统计学意义(P>0.05),实验后各周HH与HO组体质量均显著低于NC组(P<0.01),HH与HO组之间差异无统计学意义(P>0.05)。3组大鼠水平自主活动度差异无统计学意义(P>0.05);垂直自主活动度HO组较NC和HH组显著提高(P<0.05,P<0.01),NC与HH组之间差异无统计学意义(P>0.05)。皮肤平均血流灌注量HH组与NC和HO组相比显著增加(P<0.01),NC与HO组之间差异无统计学意义(P>0.05)。结论:模拟海拔5 000 m高原慢性缺氧环境下便携式氧气机富氧能够显著降低大鼠血流灌注量至平原水平,可为大鼠适应更复杂恶劣的高原环境进行血液系统代偿的功能储备;模拟海拔5 000 m高原慢性缺氧环境下便携式氧气机富氧能够显著提升大鼠空间探索与认知能力,对高原缺氧环境下大鼠脑功能具有一定保护与促进作用。

Objective To simulate a chronic hypoxic environment, and then explore the effects of oxygen-enriched atmospheres provided by portable oxygen-enriched machine on the behaviors of rats in such environment. Methods Chronic hypoxic environment at a 5 000 m high altitude was simulated with small hypobaric chamber, and oxygen-enriched rooms were established by portable oxygen-enriched machines and individually ventilated cages. Thirty-six male Sprague-Dawley rats were randomly divided into 3 groups, including normal control group （NC group）, high altitude hypoxia group （HH group） and high altitude oxygen enrichment group （HO group）. Rats in HH group and HO group were fed in the small hypobaric chamber for 4 weeks （22 h/d）, and rats in HO group were stay in oxygen-enriched rooms for 8 h every day. Rats in NC group were fed outside of the chamber. Bodyweight of rats were measured before treatment and at every week after the treatment. The behavior indices and mean values of skin blood flux were measured after the treatment. Results No statistical differences were found in the bodyweight of rats in 3 groups before treatment （P〉0.05）. After the treatment, the bodyweight of rats in HH group and HO group were significantly lower than that of rats in NC group （P〈0.01）, and no statistical difference was found between HH group and HO group （P〉0.05）. The comparison of the horizontal activity of the rats among 3 groups didn’t showed any statistical differences （P〉0.05）. Compared with that in NC group and HH group, the vertical activity of the rats in HO group was significantly increased （P〈0.05, P〈0.01）, and no statistical difference was found between NC group and HH group （P〉0.05）. The rats in HH group had a significantly higher mean value of skin blood flux, as compared with the rats in NC group and HO group （P〈0.01）, and no statistical difference was found between NC group and HO group （P〉0.05）. Conclusion In a simulated chronic hypoxic environment at a 5 000 m high altitude, portable oxygen-enriched machine not only enhances the adaptive ability of rats by reducing the values of blood flux and the functional reserve of blood system, but also improves the brain function of rats such as cognitive ability and space exploration ability.