McFalls E O, Pantely G A, Anselone C G, Bristow D J
Department of Medicine, Oregon Health Sciences University.
Cardiovasc Res. 1990 Oct;24(10):813-20. doi: 10.1093/cvr/24.10.813.
The aim was to test the hypothesis that the release of vascular tone with adenosine during constant flow ischaemia alters both transmural function and regional metabolism in a detrimental way.
In one group of anaesthetised swine, the effects of graded reductions of flow on segmental left ventricular function, myocardial oxygen consumption (MVO2), and lactate production in the distribution of the left anterior descending coronary artery (LAD) were determined. In a second group, a model of constant flow ischaemia was induced to test how altering vascular tone with adenosine changed the relationship of flow, function, and metabolism.
The experiments were performed in 20 open chest, anaesthetised swine. Protocol A consisted of 11 animals and protocol B of nine animals.
In protocol A, during graded ischaemia, reductions in flow, % systolic wall thickening (WTh), normalised MVO2 and % lactate extraction (%LE) correlated well with reductions in coronary perfusion pressure when fitted with 3rd order polynominal curves (r = 0.78, 0.87, 0.85 and 0.81 respectively; p less than 0.00001). In protocol B, during constant flow ischaemia, at control, % WTh was 33 (SD 11)%, mean coronary artery pressure was 72(10) mm Hg, mean LAD transmural flow was 0.99(0.43) ml.min-1.g-1, and % LE was +14(9)%. With inflation of a hydraulic occluder on the LAD, perfusion pressure was lowered to 38(5) mm Hg and transmural flow dropped to 0.76(0.31) ml.min-1.g-1 (intact vasomotion). During an infusion of intracoronary adenosine with flow held constant (absent vasomotion), %WTh was further reduced from 27(9) to 13(10) (p less than 0.001), and %LE from -18(42) to -70(61) (p less than 0.05). MVO2 with and without vasomotion did not differ significantly at 3.14(0.75) and 3.18(0.86) ml.min-1.g-1 respectively.
In swine coronary circulation, reductions in regional function, MVO2 and lactate production correlate well with reductions in flow and perfusion pressure during ischaemia with vasomotor tone intact. The effect of adenosine on vascular tone during constant flow ischaemia caused dramatic reductions in function and lactate extraction without altering MVO2. This emphasises the important role of vascular tone in protecting both transmural function and regional metabolism during moderate ischaemia.
旨在验证以下假设，即在恒流缺血期间，腺苷引起的血管张力变化会以有害的方式改变透壁功能和局部代谢。
在一组麻醉猪中，测定左前降支冠状动脉（LAD）分布区域内血流逐渐减少对节段性左心室功能、心肌耗氧量（MVO2）和乳酸生成的影响。在另一组中，诱导建立恒流缺血模型，以测试腺苷改变血管张力如何改变血流、功能和代谢之间的关系。
实验在20只开胸麻醉猪身上进行。方案A包括11只动物，方案B包括9只动物。
在方案A中，在逐渐缺血期间，当用三次多项式曲线拟合时，血流减少、收缩期壁增厚百分比（WTh）、标准化MVO2和乳酸提取百分比（%LE）与冠状动脉灌注压降低密切相关（r分别为0.78、0.87、0.85和0.81；p小于0.00001）。在方案B中，在恒流缺血期间，对照组时，%WTh为33（标准差11）%，平均冠状动脉压为72（10）mmHg，平均LAD透壁血流为0.99（0.43）ml·min-1·g-1，%LE为+14（9）%。在LAD上充水封堵器后，灌注压降至38（5）mmHg，透壁血流降至0.76（0.31）ml·min-1·g-1（血管运动完整）。在冠状动脉内输注腺苷且血流保持恒定（无血管运动）期间，%WTh从27（9）进一步降至13（10）（p小于0.001），%LE从-18（42）降至-70（61）（p小于0.05）。有血管运动和无血管运动时的MVO2分别为3.14（0.75）和3.18（0.86）ml·min-1·g-1，差异无统计学意义。
在猪冠状动脉循环中，在血管运动张力完整的缺血期间，局部功能、MVO2和乳酸生成的减少与血流和灌注压的降低密切相关。恒流缺血期间腺苷对血管张力的影响导致功能和乳酸提取显著降低，而不改变MVO2。这强调了血管张力在中度缺血期间保护透壁功能和局部代谢方面的重要作用。
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