中文摘要：

[目的]对比观察常温和低温饲养条件下肉鸡肺动脉压、血液脂质过氧化水平和肺阻力血管显微结构的变化,以探讨肺血管重构的机理及其在肉鸡肺动脉高压综合征（PHS）形成中的病理意义.[方法]商品代艾维茵肉鸡180羽,14日龄时随机分为两组, 一组为常温对照组,按常规饲养;一组为低温诱病组.试验过程中连续测定肉鸡平均肺动脉压（mPAP）、右心/全心比（RV/TV）;测定血浆超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）活性和丙二醛（MDA）水平;采集肺组织进行弹力纤维染色,应用计算机图像分析系统测定肺小动脉平均中膜厚度（mMTPA）和相对中膜面积（WA/TA）.[结果]低温组mPAP, RV/TV值和血浆MDA浓度比常温组显著升高;低温组肉鸡肺小动脉mMTPA和WA/TA显著高于常温组;回归分析表明,血浆MDA值与mMTPA,WA/TA显著正相关, mPAP与mMTPA,WA/TA亦呈显著正相关.[结论]低温条件下肉鸡体内脂质过氧化作用增强、肺动脉压升高,导致肺血管重构并进一步升高肺动脉压,这一改变是低温诱导肉鸡PHS形成的重要病理基础之一.

英文摘要：

[Objective] The changes of pulmonary pressure, lipid peroxidation and microstructure of pulmonary resistance vessel of low or normal temperature treated broilers were investigated to study the mechanism of pulmonary vascular remodeling and its role in the pathogenesis of pulmonary hypertension syndrome （PHS）. [Method] 180 Avian commercial broilers were randomly allocated to two groups at 14-day-old age. The group reared under normal ambient temperature served as control group. Another group was exposed to low ambient temperature to induce PHS. The ratio of right ventricular weight to total ventricular weight （RV/TV） and mean pulmonary artery pressure （mPAP） were continuously surveyed. Blood samples were taken to measure the plasma malonilaldehyde （MDA）, superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px） levels. Lung samples were taken and stained for elastin. The vessel wall area to vessel total area ratio （WA/TA） and mean media thickness in pulmonary arterioles （mMTPA） were measured by using microscopic image analysis software. [Result] The mPAP, RV/TV ratio and MDA concentration were significantly higher in low temperature treatment group compared with control group. The WA/TA and mMTPA in pulmonary arterioles were significantly increased in low temperature treatment group. Correlation analysis showed that the plasma MDA concentration and mPAP were significantly correlated with WA/TA and mMTPA. [Conclusion] The results indicated that the promoted lipid peroxidation and pulmonary hypertension in low temperature treated broiler had led to pulmonary vascular remodeling and in turn higher pulmonary artery pressure. These changes seem to be possessed of great importance in the pathologenesis of PHS in broilers induced by low ambient temperature.