Preoperative exercise therapy protects the liver from ischemia-reperfusion injury

Abstract

Abstract Introduction Surgical stress such as hepatic ischemia/reperfusion (I/R) injury results in an increased risk of postoperative morbidity and mortality, including liver transplantation. Preoperative exercise therapy has been shown to enhance physical capacity at the moment of hospital admission and may facilitate better recovery after surgery. However, the mechanisms behind this protection remain to be elucidated. Here we hypothesize that preoperative aerobic exercise therapy has protective effects as a result of inhibiting sterile inflammatory processes after liver I/R injury. Methods Eight-week-old male C57BL/6 mice were randomly divided into exercise (n=15) or sedentary (n=15) groups. The exercise group ran on a motorized treadmill for 60 min/day, 5 days/week at a speed of 12.5m/min for 4 weeks. 70% partial liver warm I/R was performed in both groups of mice at 72 hours after the final exercise session. Results After 4 weeks,60% exercised mice showed a 3%–6% weight loss whereas the weight of all sedentary mice were increased. The sALT levels was significantly reduced in the exercise mice than the sedentary mice after liver I/R. Significantly increased Natural Killer (NK) cells were observed, whereas less neutrophil infiltration was seen in exercise mice after I/R, suggesting a link between hepatic immune modulation and exercise. Moreover, the lactate dehydrogenase (LDH), apoptosis, reactive oxygen species (ROS) in hepatocyte were all decreased in exercise mice. Conclusions These data show beneficial effects of preoperative exercise therapy on the experimental model of liver I/R injury, which offer a rationale for encouraging predisposed patients of HCC or other end-stage liver diseases that need liver surgery.