Laughlin M H, Overholser K A, Bhatte M J
Department of Veterinary Biomedical Sciences, University of Missouri, Columbia 65211.
J Appl Physiol (1985). 1989 Sep;67(3):1140-9. doi: 10.1152/jappl.1989.67.3.1140.
Female yucatan miniature swine were trained on a treadmill (ET) or were cage confined (C) for 16-22 wk. The ET pigs had increased exercise tolerance, heart weight-to-body weight ratio, and skeletal muscle oxidative capacity. After anesthesia the left anterior descending coronary artery was cannulated and pump perfused with blood while aortic, central venous, and coronary perfusion pressures, electrocardiogram, heart rate, and coronary blood flow were monitored. Capillary permeability-surface area product (PS) for EDTA was determined with the single-injection indicator-diffusion method by use of an organ model based on the Sangren-Sheppard equations for capillary transport. Coronary blood flow (CBF) and PS were compared before and during maximal adenosine vasodilation with coronary perfusion pressures at 120 mmHg. Results indicate that there were no differences in base-line CBF or PS between C and ET groups. alpha-Receptor blockade with phentolamine and/or prazosin, before adenosine vasodilation, produced increases in PS in C pigs but had little effect in ET pigs. During maximal vasodilation with adenosine, ET pigs had greater CBF (447 +/- 24 vs. 366 +/- 27 ml.min-1.100 g-1) and greater PS (83 +/- 9 vs. 55 +/- 7 ml.min-1.100 g-1) than the C group. It is concluded that ET induces an increased coronary transport capacity in miniature swine that includes a 22% increase in blood flow capacity and a 51% increase in capillary exchange capacity.
雌性尤卡坦小型猪在跑步机上训练（ET组）或关在笼中（C组）16 - 22周。ET组猪的运动耐力、心脏重量与体重比以及骨骼肌氧化能力均有所提高。麻醉后，将左前降支冠状动脉插管并用血液进行泵灌注，同时监测主动脉、中心静脉和冠状动脉灌注压、心电图、心率及冠状动脉血流量。采用基于Sangren - Sheppard毛细血管转运方程的器官模型，通过单次注射指示剂扩散法测定EDTA的毛细血管通透性 - 表面积乘积（PS）。在冠状动脉灌注压为120 mmHg时，比较最大腺苷血管舒张前后的冠状动脉血流量（CBF）和PS。结果表明，C组和ET组的基线CBF或PS无差异。在腺苷血管舒张前，用酚妥拉明和/或哌唑嗪阻断α受体，可使C组猪的PS增加，但对ET组猪影响不大。在腺苷最大血管舒张期间，ET组猪的CBF（447±24 vs. 366±27 ml·min⁻¹·100 g⁻¹）和PS（83±9 vs. 55±7 ml·min⁻¹·100 g⁻¹）均高于C组。结论是，ET可诱导小型猪冠状动脉转运能力增强，包括血流量能力增加22%和毛细血管交换能力增加51%。
