Lorenzoni A G, Anthony N B, Wideman R F
Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA.
Poult Sci. 2008 Jan;87(1):125-32. doi: 10.3382/ps.2007-00178.
Previous hemodynamic evaluations demonstrated that pulmonary arterial pressure (PAP) is higher in broilers that are susceptible to pulmonary hypertension syndrome (PHS, ascites) than in broilers that are resistant to PHS. We compared key pulmonary hemodynamic parameters in broilers from PHS-susceptible and PHS-resistant lines (selected for 12 generations under hypobaric hypoxia) and in broilers from a relaxed (control) line. In experiment 1 the PAP was measured in male broilers in which a flow probe positioned on one pulmonary artery permitted the determination of cardiac output and pulmonary vascular resistance (PVR). The PAP and relative PVR were higher in susceptible broilers than in relaxed and resistant broilers, whereas absolute and relative cardiac output did not differ between lines. In experiment 2 male and female broilers from the 3 lines were catheterized to measure pressures in the wing vein, right atrium, right ventricle, pulmonary artery, and pulmonary veins (WP, wedge pressure). The transpulmonary pressure gradient (TPG) was calculated as (PAP-WP), with PAP quantifying precapillary pressure and WP approximating postcapillary pulmonary venous pressure. When compared with resistant and relaxed broilers, PAP values in susceptible broilers were > or =10 mmHg higher, TPG values were > or =8 mmHg higher, and WP values were < or =2 mmHg higher, regardless of sex. The combined hemodynamic criteria (elevated PAP and PVR combined with a proportionally elevated TPG) demonstrate that susceptibility to PHS can be attributed primarily to pulmonary arterial hypertension associated with increased precapillary (arteriole) resistance rather than to pulmonary venous hypertension caused by elevated postcapillary (venous and left atrial) resistance.
先前的血流动力学评估表明，易患肺动脉高压综合征（PHS，腹水症）的肉鸡的肺动脉压（PAP）高于对PHS有抗性的肉鸡。我们比较了来自易患PHS品系和抗PHS品系（在低压缺氧条件下选育了12代）的肉鸡以及来自宽松（对照）品系的肉鸡的关键肺血流动力学参数。在实验1中，对雄性肉鸡测量PAP，其中放置在一条肺动脉上的流量探头可用于测定心输出量和肺血管阻力（PVR）。易患PHS的肉鸡的PAP和相对PVR高于宽松品系和抗性品系的肉鸡，而品系间的绝对和相对心输出量没有差异。在实验2中，对来自这3个品系的雄性和雌性肉鸡进行插管，以测量翼静脉、右心房、右心室、肺动脉和肺静脉的压力（WP，楔压）。经肺压力梯度（TPG）计算为（PAP - WP），其中PAP代表毛细血管前压力，WP近似于毛细血管后肺静脉压力。与抗性和宽松品系的肉鸡相比，无论性别如何，易患PHS的肉鸡的PAP值高≥10 mmHg，TPG值高≥8 mmHg，WP值高≤2 mmHg。综合血流动力学标准（升高的PAP和PVR以及成比例升高的TPG）表明，对PHS的易感性主要可归因于与毛细血管前（小动脉）阻力增加相关的肺动脉高压，而非由毛细血管后（静脉和左心房）阻力升高引起的肺静脉高压。
