Moderate Hypothermia Provides Better Protection of the Intestinal Barrier than Deep Hypothermia during Circulatory Arrest in a Piglet Model: A Microdialysis Study

IntroductionThis study aimed to assess the effects of different temperature settings of hypothermic circulatory arrest (HCA) on intestinal barrier function in a piglet model.MethodsTwenty Wuzhishan piglets were randomly assigned to 40 min of HCA at 18°C (DHCA group, n = 5), 40 min of HCA at 24°C (MHCA group, n = 5), normothermic cardiopulmonary bypass (CPB group, n = 5) or sham operation (SO group, n = 5). Serum D-lactate (SDL) and lipopolysaccharide (LPS) levels were determined. Microdialysis parameters (glucose, lactate, pyruvate and glycerol) in the intestinal dialysate were measured. After 180 min of reperfusion, intestinal samples were harvested for real-time polymerase chain reaction and western blotting measurements for E-cadherin and Claudin-1.ResultsHigher levels of SDL and LPS were detected in the DHCA group than in the MHCA group (P ConclusionHCA altered the energy metabolism and expression of epithelial junctions in the intestine. Moderate hypothermia (24°C) was less detrimental to the markers of normal functioning of the intestinal barrier than deep hypothermia (18°C).引言：本研究旨在评估低温停循环（hypothermic circulatory arrest, HCA）不同温度设置对仔猪模型肠道屏障功能的影响。 方法：将20头五指山仔猪随机分为4组，分别接受18℃低温停循环40分钟（深低温停循环组，DHCA组，n=5）、24℃低温停循环40分钟（中低温停循环组，MHCA组，n=5）、常温体外循环（cardiopulmonary bypass, CPB）组（n=5）以及假手术组（SO组，n=5）。检测各组血清D-乳酸（serum D-lactate, SDL）与脂多糖（lipopolysaccharide, LPS）水平；测定肠道透析液的微透析参数，包括葡萄糖、乳酸、丙酮酸及甘油。再灌注180分钟后，采集肠道样本，采用实时聚合酶链式反应与蛋白质印迹法检测上皮钙黏蛋白（E-cadherin）和紧密连接蛋白-1（Claudin-1）的表达水平。 结果：深低温停循环组的血清D-乳酸与脂多糖水平均高于中低温停循环组（P 结论：低温停循环会改变肠道的能量代谢与上皮连接蛋白的表达。相较于深低温（18℃），中低温（24℃）对肠道屏障正常功能标志物的损害程度更低。