大鼠左全肺切除致右心室重塑的研究

Right ventricular remodeling induced by left total pneumonectomy in rats

目的探讨大鼠左全肺切除术后余肺高血流量及缺氧是否导致肺动脉高压发生,进而导致右心室重塑,以及其可能的发生机制。方法健康雄性SD大鼠24只,分为2组:实验组(n=12)大鼠行左全肺切除术,对照组(n=12)大鼠行假手术。术后饲养12周后用右心导管法测定平均肺动脉压(mPAP);检测大鼠动脉血氧分压;检测右心室肥大指数即右心室/(左心室+室间隔)[right ventricle/left ventricle+septum,RV/(LV+S)]比值;光镜下观察及测量心肌细胞及小动脉形态学变化。结果实验组大鼠mPAP及RV/(LV+S)明显高于对照组[mPAP:(31.91±1.98)mmHgvs(17.82±1.94)mmHg,RV/(LV+S):(0.249±0.024)vs(0.225±0.015),P<0.01],血氧分压明显低于对照组[(77.46±5.36)mmHgvs(90.39±6.02)mmHg,P<0.01],心肌细胞直径明显大于对照组[(25.55±1.95)μmvs(15.55±1.75)μm,P<0.01],心肌小动脉管壁厚度占外径的百分率、心肌小动脉管壁面积占血管总面积的百分率均明显高于对照组(P<0.01);实验组大鼠RV/(LV+S)与mPAP呈正直线相关(r=0.879,P<0.01),mPAP与血氧分压呈负直线相关(r=-0.862,P<0.01)。结论大鼠左全肺切除术后余肺高血流量及缺氧可使肺动脉压力升高,进而导致心肌小动脉增生、右心室肥大。

Objective To study the effect of high pulmonary blood flow and hypoxia in right ventricular remodeling induced by left total pneumonectomy in rats and its mechanism. Methods Twenty-four male SD rats were randomly divided into experimental group （left pneumoneetomy, n = 12 ） and control group （sham operation, n = 12）. After 12 weeks of feeding, mean pulmonary arterial pressure （mPAP） of each rat was evaluated using a right cardiac catheterization procedure. Partial artery oxygen pressure was measured. The Ratio of Right ventricular mass/left ventricle plus septum （RV/LV ＋ S ） ratio was calculated. Changes in myocardial cells and arterioles were observed. Results The mPAP and RV/（ LV ＋ S） were obviously higher in experimental group than in control group （P 〈 0.01 ）. The partial artery oxygen pressure was lower in experimental group than in control group （ P 〈 0.01 ）. The diameter of myocardial cells was significantly larger in experimental group than in control group （P 〈 0.01 ）. The ratio of myocardial arteriolar medial thickness, external diameter and medial area to total arteriole area was obviously higher in experimental group than in control group （P 〈 0.01 ）. The RV/（ LV ＋ S） was positively correlated with mPAP. mPAP was negatively correlated with partial artery oxygen pressure. Conclusion After left total pneumonectomy, high pulmonary blood flow in residual lung and hypoxia can increase pulmonary artery pressure, thus inducing hyperplasia of myocardial arteriole and hypertrophy, i. e, right ventrieular remodeling.