Onohara T, Okadome K, Ishii T, Yamamura S, Komori K, Sugimachi K
Second Department of Surgery, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
J Surg Res. 1993 Sep;55(3):344-50. doi: 10.1006/jsre.1993.1152.
The effects of changes in shear stress (shear stress variation) on production of prostacyclin (PGI2) were examined in canine autologous vein grafts, which were implanted in the poor or normal distal runoff limbs. Four weeks after grafting, the vein grafts were perfused ex vivo and PGI2 was assayed as 6-ketoprostaglandin F1 alpha. The vein grafts were perfused under constant flow for the first 30 min and then under pulsatile flow simulating an abnormal flow with a low shear stress variation or a normal flow with a high shear stress variation for the next 30 min. Basal production rates (30-min cumulative PGI2 production) of vein grafts implanted in the poor runoff and normal runoff limbs were 1.97 +/- 0.71 and 2.19 +/- 0.40 ng/cm2, respectively, with no significant difference. Pulsatile flow effects (increased PGI2 production between 30 and 60 min) of simulated abnormal versus normal flow were 0.50 +/- 0.50 ng/cm2 versus 2.31 +/- 1.87 ng/cm2 in vein grafts implanted in poor runoff limbs (P < 0.05) and 0.48 +/- 0.41 ng/cm2 versus 3.48 +/- 1.08 ng/cm2 in vein grafts implanted in normal runoff limbs (P < 0.01), respectively. There were no significant differences in simulated normal flow effects between poor runoff limbs and normal runoff limbs. The results indicate that the release of PGI2 in vein grafts may decrease in the presence of an abnormal blood flow with a low shear stress variation. In addition, it is suggested that even vein grafts implanted in the poor runoff could increase PGI2 production once the grafts were placed into normal arterial circulation.
在植入到远端血流不佳或正常的犬自体静脉移植物中，研究了剪切应力变化（剪切应力变异）对前列环素（PGI2）生成的影响。移植后四周，对静脉移植物进行体外灌注，并将PGI2测定为6-酮前列腺素F1α。静脉移植物在最初30分钟内以恒定流量灌注，然后在接下来的30分钟内以模拟低剪切应力变异的异常血流或高剪切应力变异的正常血流进行搏动性灌注。植入到血流不佳和正常血流肢体的静脉移植物的基础生成率（30分钟累积PGI2生成量）分别为1.97±0.71和2.19±0.40 ng/cm2，无显著差异。在植入到血流不佳肢体的静脉移植物中，模拟异常血流与正常血流的搏动性血流效应（30至60分钟之间PGI2生成增加）分别为0.50±0.50 ng/cm2和2.31±1.87 ng/cm2（P<0.05），在植入到正常血流肢体的静脉移植物中分别为0.48±0.41 ng/cm2和3.48±1.08 ng/cm2（P<0.01）。血流不佳肢体和正常血流肢体之间的模拟正常血流效应无显著差异。结果表明，在剪切应力变异低的异常血流情况下，静脉移植物中PGI2的释放可能会减少。此外，还表明，即使是植入到血流不佳部位的静脉移植物，一旦置于正常动脉循环中，也可以增加PGI2的生成。
