Department of Thoracic and Cardiovascular Surgery, University Hospital of Saarland, Homburg/Saar, Germany.
J Thorac Cardiovasc Surg. 2013 Feb;145(2):539-47. doi: 10.1016/j.jtcvs.2012.03.014. Epub 2012 Apr 30.
Gastrointestinal blood flow can be compromised during and after cardiopulmonary bypass. Endothelin has been shown to be involved in the intestinal microcirculatory disturbance of sepsis. The aim of the present study was to analyze the involvement of the endothelin system on intestinal blood flow regulation during cardiopulmonary bypass and the effect of vasopressin given during cardiopulmonary bypass.
A total of 24 pigs were studied in 4 groups (n = 6): group I, sham; group II, ischemia/reperfusion with 1 hour of superior mesenteric artery occlusion; group III, cardiopulmonary bypass for 1 hour; and group IV, 1 hour of cardiopulmonary bypass plus vasopressin administration, maintaining the baseline arterial pressure. All the pigs were reperfused for 90 minutes. During the experiment, the hemodynamics and jejunal microcirculation were measured continuously. The jejunal mucosal expression of endothelin-1 and its receptor subtypes A and B were determined using polymerase chain reaction.
During cardiopulmonary bypass, superior mesenteric artery flow was preserved but marked jejunal microvascular impairment occurred compared with baseline (mucosal capillary density, 192.2 ± 5.4 vs 150.8 ± 5.1 cm/cm(2); P = .005; tissue blood flow, 501.7 ± 39.3 vs 332.3 ± 27.9 AU; P = .025). The expression of endothelin-1 after cardiopulmonary bypass (3.2 ± 0.4 vs 12.2 ± 0.8 RQ, P = .006) and endothelin subtype A (0.7 ± 0.2 vs 2.4 ± 0.6 RQ; P = .01) was significantly increased compared to the sham group. Vasopressin administration during cardiopulmonary bypass led to normal capillary density (189.9 ± 3.9 vs 178.0 ± 6.3; P = .1) and tissue blood flow (501.7 ± 39.3 vs 494.7 ± 44.4 AU; P = .4) compared with baseline. The expression of endothelin-1 (3.2 ± 0.4 vs 1.8 ± 0.3 RQ; P = .3) and endothelin subtype A (0.7 ± 0.2 vs 0.9 ± 0.2 RQ; P = .5) was not different from the sham group.
Cardiopulmonary bypass leads to microvascular impairment of jejunal microcirculation, which is associated with the upregulation of endothelin-1 and endothelin subtype A. The administration of vasopressin minimizes these cardiopulmonary bypass-associated alterations.
心肺转流术期间和之后，胃肠道血流可能会受到影响。已有研究表明，内皮素参与了脓毒症时肠道微循环障碍。本研究旨在分析内皮素系统在心肺转流术期间对肠道血流调节的作用，以及心肺转流术期间给予血管加压素的效果。
将 24 头猪分为 4 组（每组 6 头）进行研究：I 组，假手术；II 组，肠系膜上动脉阻断 1 小时再灌注；III 组，心肺转流 1 小时；IV 组，心肺转流 1 小时并给予血管加压素，维持基础动脉压。所有猪均再灌注 90 分钟。实验过程中，连续测量血流动力学和空肠微循环。采用聚合酶链反应测定空肠黏膜内皮素-1及其受体亚型 A 和 B 的表达。
与基线相比，心肺转流术期间肠系膜上动脉血流得到保留，但空肠微血管明显受损（黏膜毛细血管密度，192.2±5.4 比 150.8±5.1cm/cm2；P=0.005；组织血流，501.7±39.3 比 332.3±27.9AU；P=0.025）。心肺转流术后内皮素-1（3.2±0.4 比 12.2±0.8RQ，P=0.006）和内皮素 A 亚型（0.7±0.2 比 2.4±0.6RQ；P=0.01）的表达显著增加。心肺转流期间给予血管加压素可使毛细血管密度（189.9±3.9 比 178.0±6.3；P=0.1）和组织血流（501.7±39.3 比 494.7±44.4AU；P=0.4）恢复正常。内皮素-1（3.2±0.4 比 1.8±0.3RQ；P=0.3）和内皮素 A 亚型（0.7±0.2 比 0.9±0.2RQ；P=0.5）的表达与假手术组无差异。
心肺转流术导致空肠微循环微血管损伤，与内皮素-1和内皮素 A 亚型的上调有关。血管加压素的应用可最大程度减少心肺转流相关的改变。
