Murray P A, Stuart R S, Fraser C D, Fehr D M, Chen B B, Rock P, Desai P M, Nyhan D P
Department of Anesthesiology/Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205.
J Appl Physiol (1985). 1992 Aug;73(2):603-9. doi: 10.1152/jappl.1992.73.2.603.
We investigated the acute and chronic effects of left lung autotransplantation (LLA) on the left pulmonary vascular pressure-flow (LP/Q) relationship in conscious dogs. Continuous LP/Q plots were generated in chronically instrumented conscious dogs 2 days, 2 wk, 1 mo, and 2 mo after LLA. Identically instrumented normal conscious dogs were studied at equal time points post-surgery. LLA had little or no effect on baseline systemic hemodynamics or blood gases. In contrast, compared with normal conscious dogs, striking active flow-independent pulmonary vasoconstriction was observed 2 days post-LLA. The slope of the LP/Q relationship was increased from a normal value of 0.275 +/- 0.021 to 0.699 +/- 0.137 mmHg.ml-1.min-1.kg-1 2 days post-LLA. Pulmonary vasoconstriction of similar magnitude was also observed on a chronic basis at 2 wk, 1 mo, and even 2 mo post-LLA. Pulmonary vasoconstriction post-LLA was not due to fixed resistance at the left pulmonary arterial or venous anastomotic sites. Finally, systemic arterial blood gases were unchanged when total pulmonary blood flow was directed to exclusively perfuse the transplanted left lung. Thus, LLA results in both acute and chronic pulmonary vasoconstriction in conscious dogs. LLA should serve as a useful stable experimental model to assess the specific effects of surgical transplantation on pulmonary vascular regulation.
我们研究了左肺自体移植（LLA）对清醒犬左肺血管压力-流量（LP/Q）关系的急性和慢性影响。在LLA术后2天、2周、1个月和2个月，对长期植入仪器的清醒犬进行连续的LP/Q绘图。在相同时间点对同样植入仪器的正常清醒犬进行研究。LLA对基线全身血流动力学或血气几乎没有影响。相比之下，与正常清醒犬相比，LLA术后2天观察到明显的非流量依赖性肺血管收缩。LLA术后2天，LP/Q关系的斜率从正常值0.275±0.021 mmHg·ml-1·min-1·kg-1增加到0.699±0.137 mmHg·ml-1·min-1·kg-1。在LLA术后2周、1个月甚至2个月的慢性期也观察到了类似程度的肺血管收缩。LLA术后的肺血管收缩并非由于左肺动脉或静脉吻合部位的固定阻力。最后，当全部肺血流专门灌注移植的左肺时，全身动脉血气没有变化。因此，LLA导致清醒犬出现急性和慢性肺血管收缩。LLA应作为一个有用的稳定实验模型，以评估手术移植对肺血管调节的特定影响。
