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).