Objectives: To explore the effects of hypoxic and hypobaric conditions on blood gas and erythrocyte-related indicators in rats.
Methods: SD male rats were exposed to low-pressure hypoxic conditions simulating an altitude of 6500 m in a small or a large experimental cabin. Abdominal aortic blood samples were collected and blood gas indicators, red blood cells (RBCs) count, and hemoglobin (Hb) content were measured. The effects of exposure to different hypoxia times, different hypoxia modes, normal oxygen recovery after hypoxia, and re-hypoxia after hypoxia preconditioning on blood gas indicators, RBCs count and Hb content were investigated.
Results: The effect of blood gas indicators was correlated with the length of exposure time of hypoxia and the reoxygenation after leaving the cabin. Hypoxia caused acid-base imbalance and its severity was associated with the duration of hypoxia; hypoxia also led to an increase in RBCs count and Hb content, and the increase was also related to the time exposed to hypoxia. The effects of reoxygenation on acid-base imbalance in rats caged in a small animal cabin were more severe that those in a large experimental cabin. Acetazolamide alleviated the effects of reoxygenation after leaving the cabin. Different hypoxia modes and administration of acetazolamide had little effect on RBCs count and Hb content. Normal oxygen recovery can alleviate the reoxygenation and acid-base imbalance of hypoxic rats after leaving the cabin and improve the increase in red blood cell and hemoglobin content caused by hypoxia. The improvement of hypoxia preconditioning on post hypoxia reoxygenation is not significant, but it can alleviate the acid-base imbalance caused by hypoxia in rats and to some extent improve the increase in red blood cell and hemoglobin content caused by hypoxia.
Conclusions: Due to excessive ventilation and elevated RBCs count and Hb content after hypoxia reoxygenation, oxygen partial pressure and other oxygenation indicators in hypoxic rats are prone to become abnormal, while blood gas acid-base balance indicators are relatively stable, which are more suitable for evaluating the degree of hypoxia injury and related pharmacological effects in rats.
目的: 探讨不同高原缺氧条件及复氧对大鼠血气及红细胞相关指标的影响。方法: SD雄性大鼠分组后，使用模拟高原低压低氧小型动物舱和大型实验舱，以6500 m为缺氧海拔，建立不同缺氧时间、不同缺氧模式、缺氧后常氧恢复，以及缺氧预适应后再缺氧的大鼠损伤模型，采集腹主动脉血并测定血气指标、红细胞及血红蛋白含量。结果: 大鼠缺氧时间越长损伤越大，出舱后复氧越严重；缺氧会造成大鼠酸碱平衡紊乱，且缺氧时间越长越严重；缺氧会导致大鼠红细胞数和血红蛋白含量升高，且缺氧时间越长升高越明显。与大型实验舱比较，小型动物舱缺氧大鼠出舱后的复氧情况、酸碱平衡紊乱更严重，而乙酰唑胺能缓解出舱后的复氧情况和酸碱平衡紊乱，但不同的缺氧模式及给予乙酰唑胺对红细胞数及血红蛋白含量影响不大。常氧恢复能缓解缺氧大鼠出舱后的复氧情况和酸碱平衡紊乱，并能改善缺氧引起的红细胞和血红蛋白含量升高。缺氧预适应对缺氧后复氧情况的改善效果不明显，但能缓解缺氧导致的大鼠酸碱平衡紊乱，并能在一定程度改善缺氧引起的红细胞数和血红蛋白含量升高。结论: 受缺氧复氧后过度换气和红细胞数、血红蛋白升高等影响，缺氧大鼠氧分压等氧合指标容易出现异常，而血气酸碱平衡指标较为稳定，更适用于大鼠缺氧损伤程度和相关药效评价。.
Keywords: Acid-base balance; Blood gas analysis; Hypoxia; Oxygenation index; Plateau; Rats; Reoxygenation.