Scheel K W, Mass H, Williams S E
Department of Physiology, Texas College of Osteopathic Medicine, Fort Worth 76107.
Am J Physiol. 1989 Feb;256(2 Pt 2):H441-5. doi: 10.1152/ajpheart.1989.256.2.H441.
In this study we utilized two methods to investigate the pressure-flow, P-F, relationship of the coronary collateral vessels in a beating, blood-perfused, isolated heart preparation. In the first method (free-flow method), 12 dog hearts were perfused at pressures ranging from 100 to 0 mmHg, whereas the retrograde flow (index of collateral flow) was measured on the circumflex coronary artery, LCA, against atmospheric pressure, first during autoregulation and then after maximum vasodilation. In the second method (back-pressure method), the back pressure to retrograde flow was varied from 0 to 100 mmHg, whereas the perfusion pressure to the remaining vessels was maintained constant at 100 mmHg. This procedure was performed on four hearts with and without embolization of the LCA by 25-microns spheres. The free-flow method demonstrated a linear P-F relationship with an average correlation coefficient, r, of 0.98. The pressure intercept was 1.7 +/- 1.2 mmHg. The back-pressure method yielded a relationship that was more curvilinear with an average pressure intercept of 13 mmHg without embolization and 38 mmHg with embolization. An analog of the coronary and collateral circulation was used to illustrate that, in the back-pressure method, changes in the coronary resistance at low pressures contributed to the nonlinearity of the collateral P-F characteristics and that the network formed between the collateral and coronary resistances was responsible for the higher pressure intercept value.
在本研究中，我们采用两种方法研究了在跳动、血液灌注的离体心脏标本中冠状动脉侧支血管的压力-流量（P-F）关系。第一种方法（自由流量法），对12只犬心脏在100至0 mmHg的压力范围内进行灌注，同时在冠状动脉左旋支（LCA）上测量相对于大气压的逆向血流（侧支血流指标），先是在自动调节期间，然后是在最大血管舒张后。第二种方法（背压法），逆向血流的背压从0变化至100 mmHg，而其余血管的灌注压力保持恒定在100 mmHg。该操作在4只心脏上进行，其中2只LCA用25微米的球体进行栓塞，另外2只未栓塞。自由流量法显示出线性的P-F关系，平均相关系数r为0.98。压力截距为1.7±1.2 mmHg。背压法得出的关系更呈曲线状，未栓塞时平均压力截距为13 mmHg，栓塞时为38 mmHg。用一个冠状动脉和侧支循环的模型来说明，在背压法中，低压时冠状动脉阻力的变化导致了侧支P-F特性的非线性，并且侧支和冠状动脉阻力之间形成的网络导致了更高的压力截距值。
