慢性低氧性肺动脉高压大鼠动脉血气分析指标的变化及其意义

Changes and Significance of Arterial Blood Gas Analysis Indexes in Rats with Chronic Hypoxic Pulmonary Hypertension

目的探讨慢性低氧诱导的低氧性肺动脉高压大鼠模型中动脉血气分析指标的变化及意义。方法随机将36只SD雄性大鼠分为常氧对照组和低氧(1、3、7、14和21 d)组,低氧组置于低氧舱(O2体积分数为10%)相应的天数。采用右心导管法测定右心室收缩压(RVSP),计算右心室(RV)与左心室(LV)+室间隔(S)质量比值,得出右心室肥厚指数(RVHI)。采用Masson染色法观察肺动脉病理结构改变。经腹主动脉取血进行动脉血气分析,测定指标包括酸碱度(pH)、动脉血二氧化碳分压(PaCO2)、动脉血氧分压(PaO2)、动脉血氧饱和度(SaO2)、碳酸氢盐(HCO3^(–))、钠离子(Na^(+))、钾离子(K^(+))、钙离子(Ca^(2+))、血细胞比容(Hct)和血红蛋白(Hb)。结果低氧各组大鼠RVSP和RVHI均明显高于常氧对照组(P<0.05)。与常氧对照组相比,低氧(7、14、21 d)组大鼠肺动脉异常重塑。与常氧对照组相比,低氧各组pH和HCO3^(–)含量均明显降低(P<0.05),低氧21 d组PaCO2显著增高(P<0.05),低氧14 d组PaO2和SaO2均明显降低(P<0.05),除低氧1 d外各组Na+浓度和低氧3 d组Ca^(2+)浓度明显降低(P<0.05),除低氧14 d外各组K+浓度显著升高(P<0.05),低氧各组Hct和Hb水平均明显升高(P<0.05)。低氧性肺动脉高压大鼠动脉血气分析中Na^(+)水平与RVSP呈负相关(P<0.05)。结论低氧性肺动脉高压大鼠动脉血气分析指标pH、PaCO2、PaO2、SaO2、HCO3^(–)、Na^(+)、K^(+)、Ca^(2+)、Hct和Hb发生明显变化,参与并调控低氧性肺动脉高压的发生发展,其中Na^(+)水平可能成为间接评估低氧性肺动脉高压严重程度的指标。

Objective To investigate the changes and significance of arterial blood gas analysis indexes in a rat model of pulmonary hypertension induced by chronic hypoxia.Methods Thirty-six SD male rats were randomly divided into the normoxic control group and the hypoxic groups.The rats in the hypoxic groups were placed in a hypoxic chamber(10%oxygen concentration)for 1,3,7,14,21 days,respectively.Right ventricular systolic pressure(RVSP)was measured by right ventricular catheter,and right ventricular hypertrophy index(RVHI)was calculated by calculating the weight ratio of right ventricle(RV)to[left ventricle(LV)+ventricular septum(S)].Masson staining was used to observe the pathological changes of pulmonary artery.Blood was taken from the abdominal aorta for the arterial blood gas analysis to determine the following indexes:pondus hydrogenii(pH),arterial partial pressure of carbon dioxide(PaCO2),arterial partial pressure of oxygen(PaO2),arterial oxygen saturation(SaO2),bicarbonate(HCO3^(–)),sodium(Na^(+)),potassium(K^(+)),calcium(Ca^(2+)),hematocrit(Hct)and hemoglobin(Hb).Results RVSP and RVHI of the rats were significantly increased in the hypoxic groups compared with the normoxic control group(P<0.05).Compared with the normoxic control group,the hypoxic groups(7,14,21 days)had abnormal pulmonary artery remodeling.Compared with the normoxic control group,the pH and HCO3^(–)levels of the hypoxic groups were significantly reduced(P<0.05);PaCO2 level was significantly increased in the hypoxic 21-day group(P<0.05),PaO2 and SaO2 levels were significantly decreased in the hypoxic 14-day group(P<0.05),the Na+concentration(except hypoxia 1-day group)and the Ca2+concentration(hypoxic 3-day group)were significantly reduced(P<0.05);the K+concentrations were increased significantly in the hypoxic groups(except hypoxia 14-day group)(P<0.05);Hct and Hb were significantly increased in the hypoxic groups(P<0.05).There was a significant negative correlation between Na+and RVSP in rats with hypoxic pulmonary hypertension(P<0.05).Conclusion The arterial blood gas analysis indexes,including pH,PaCO2,PaO2,SaO2,HCO3^(–),Na^(+),K^(+),Ca^(2+),Hct and Hb are significantly changed,and participate in and regulate the development and progression of hypoxic pulmonary hypertension in rats,in which Na+level may be used as an indicator to evaluate the severity of hypoxic pulmonary hypertension indirectly.