Gardaz J P, McFarlane P A, Sykes M K
J Appl Physiol (1985). 1986 Mar;60(3):959-64. doi: 10.1152/jappl.1986.60.3.959.
Dopamine increases blood flow to a hypoxic left lower lobe in dogs. To elucidate possible mechanisms, left lower lobe collapse was induced in anesthetized dogs, and lobar (QLLL) and total (QT) pulmonary blood flow was measured by electromagnetic flow probes. Dopamine infusion increased mean pulmonary arterial pressure (Ppa), QT, and QLLL. However, the increase in QLLL was double that produced by a similar increase in Ppa without increase in QT (inflation of a Swan-Ganz balloon in right pulmonary artery) or by a similar increase in QT with smaller increase in Ppa (opening of arteriovenous fistulas). QLLL/QT was not changed by opening arteriovenous fistulas, but was increased by Swan-Ganz balloon inflation, and by infusion of dopamine. It is concluded that the increase in QLLL/QT produced by dopamine was due to a decrease in hypoxic vasoconstriction in the lobe secondary to an increase in mixed venous PO2 and to vasoconstriction in the oxygenated lung.
多巴胺可增加犬缺氧左下叶的血流量。为阐明可能的机制，在麻醉犬中诱发左下叶萎陷，并用电磁血流探头测量叶部（QLLL）和总肺血流量（QT）。输注多巴胺可增加平均肺动脉压（Ppa）、QT和QLLL。然而，QLLL的增加量是在Ppa相似增加而QT无增加（右肺动脉内充胀Swan-Ganz球囊）或QT相似增加而Ppa增加较小（开放动静脉瘘）时产生增加量的两倍。开放动静脉瘘不会改变QLLL/QT，但Swan-Ganz球囊充胀以及输注多巴胺会使其增加。得出的结论是，多巴胺导致的QLLL/QT增加是由于混合静脉血氧分压升高继发叶部缺氧性血管收缩减弱以及氧合肺血管收缩所致。
