冠状动脉狭窄小型猪+Gz耐力及血浆CRP和ET-1变化观察

目的：以巴马小型猪为冠状动脉狭窄模型,观察其在最大＋Gz暴露下动物耐受性及血浆C反应蛋白（C-reactive protein,CRP）和内皮素-1（endothelin-1,ET-1)含量的变化关系。方法将20头巴马小型猪通过胸腔镜直视下手术丝线永久性结扎建模,分为冠状动脉轻度、中度、重度狭窄3组（每组5头）和假手术组（5头）。在动物离心机最高暴露不超过+9 Gz情况下,分别观察最大+Gz耐受能力和血浆CRP及ET-1的变化关系。结果＋Gz暴露下,同轻度狭窄组和假手术组比较,中度和重度狭窄组的最大+Gz耐受值均显著降低（P＜0.05）;同假手术组比较,中度和重度狭窄组中血浆CRP、ET-1水平均显著增高（P＜0.05）,轻度狭窄组差异无统计学意义。+Gz暴露下血浆CRP与ET-1呈显著正相关（r＝0.894,P＜0.01）。结论狭窄程度越重,模型耐受+Gz能力越低;同时,血浆CRP及ET-1呈线性关系升高变化。

Study of relationship of positive acceleration tolerance and plasma C-reactive protein and endothelin-1 levels in swines with different coronary artery stenosis

Objective To study the relationships between positive acceleration (+Gz) tolerance and the changes of plasma C-reactive protein (CRP) and endothelin-1 (ET-1) levels in swines with different coronary artery stenosis. Methods Fifteen of the twenty Bama miniature swines were randomly assigned to three observation groups using silk suture under direct vision of the thoracoscope to establish different coronary artery stenosis models: mild, moderate and severe. Another 5 swines underwent a sham operation as control group. The relationships between positive acceleration (+Gz) tolerance and plasma C-reactive protein and endothelin-1 levels in swines were observed under exposure to +Gz stress (<9 Gz) in the centrifuge model. Results Compared to mild stenosis group and sham-operation group, the maximal tolerated +Gz values in moderate stenosis group and severe stenosis group were decreased significantly under +Gz exposure(P<0.05). Compared to the sham-operation group, the levels of plasma CRP and ET-1 were significantly increased in moderate stenosis group and severe stenosis group (P<0.05). There were no significant changes of plasma CRP and ET-1 in mild stenosis group. A significant correlation between plasma CRP and ET-1 was observed under +Gz exposure(r=0.894,P<0.01). Conclusion The greater stenosis becomes, a greater degradation of positive acceleration (+Gz) tolerance is observed. Meanwhile, the level of plasma CRP and ET-1 can increase synchronously under +Gz exposure.