Maggiorini M, Brimioulle S, De Canniere D, Delcroix M, Naeije R
Laboratory of Cardiovascular and Respiratory Physiology, Erasme University Hospital, B-1070 Brussels, Belgium.
J Appl Physiol (1985). 1998 Mar;84(3):815-21. doi: 10.1152/jappl.1998.84.3.815.
Pigs have been reported to present with a stronger pulmonary vascular reactivity than many other species, including dogs. We investigated the pulmonary vascular impedance response to autologous blood clot embolic pulmonary hypertension in anesthetized and ventilated minipigs (n = 6) and dogs (n = 6). Before embolization, minipigs, compared with dogs, presented with higher mean pulmonary arterial pressure (Ppa; by an average of 9 mmHg), a steeper slope of Ppa-flow (Q) relationships, and higher 0-Hz impedance (Z0) and first-harmonic impedance (Z1), without significant differences in characteristic impedance (Zc), and a lower ratio of pulsatile hydraulic power to total hydraulic power. Embolic pulmonary hypertension (mean Ppa: 40-55 mmHg) was associated with increased Z0 and Z1 in both species, but the minipigs had a steeper slope of Ppa/Q plots and an increased Zc. At identical Q and Ppa, minipigs still presented with higher Z1 and Zc and a lower ratio of pulsatile hydraulic power to total hydraulic power. The energy transmission ratio, defined as the hydraulic power in the measured waves divided by the hydraulic power in the forward waves, was better preserved after embolism in minipigs. No differences in wave reflection indexes were found before and after embolism. We conclude that minipigs, compared with dogs, present with a higher pulmonary vascular resistance and reactivity and adapt to embolic pulmonary hypertension by an increased Zc without earlier wave reflection. These differences allow for a reduced pulsatile component of hydraulic power and, therefore, a better energy transfer from the right ventricle to the pulmonary circulation.
据报道，猪的肺血管反应性比包括狗在内的许多其他物种更强。我们研究了麻醉通气状态下的小型猪（n = 6）和狗（n = 6）对自体血凝块栓塞性肺动脉高压的肺血管阻抗反应。在栓塞前，与狗相比，小型猪的平均肺动脉压（Ppa）更高（平均高9 mmHg），Ppa-血流（Q）关系的斜率更陡，0 Hz阻抗（Z0）和一次谐波阻抗（Z1）更高，特征阻抗（Zc）无显著差异，搏动性水力功率与总水力功率之比更低。栓塞性肺动脉高压（平均Ppa：40 - 55 mmHg）在两个物种中均与Z0和Z1增加有关，但小型猪的Ppa/Q图斜率更陡且Zc增加。在相同的Q和Ppa下，小型猪的Z1和Zc仍然更高，搏动性水力功率与总水力功率之比更低。能量传输比定义为测量波中的水力功率除以前向波中的水力功率，在小型猪栓塞后得到更好的保留。栓塞前后波反射指数无差异。我们得出结论，与狗相比，小型猪具有更高的肺血管阻力和反应性，并通过增加Zc来适应栓塞性肺动脉高压，且没有更早的波反射。这些差异使得水力功率的搏动成分减少，因此从右心室到肺循环的能量传递更好。
