OBJECTIVETo investigate the mechanism of how vacuum sealing drainage (VSD) ameliorating ischemia reperfusion (I/R) injury in skeletal muscle I/R model.

METHODSThirty New Zealand white rabbits were divided into three groups: control (sham operation) group, I/R group, VSD+ I/R group.The ischemia of the left hind limb of the animal was induced by clamping the common femoral artery and vein. After 4 hours of ischemia, the clamp was removed and the hind limp underwent 6 hours reperfusion. VSD treated animals received the treatment at the beginning of reperfusion. The concentrations of myeloperoxidase (MPO), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) in muscular tissues were assayed. HE stained pathological section was used to evaluate the degree of edema of muscular tissues, and the immunohistochemistry was used to detect the percentage of positive cells expressing high mobility group protein B1 (HMGB1). Q-RT-PCR and Western Blot were used to detect the mRNA levels and protein expression of HMGB1 in myocyte respectively. The experimental data was tested using variance analysis.

RESULTSThe levels of inflammatory factors and antioxidant factors in muscular tissues were significantly different in the I/R group compared to the VSD group and control group (the levels of MPO in I/R group, I/R+ VSD group and control group were 0.91±0.22, 0.53±0.08, 0.31±0.10, respectively, F=26.48, P=0.000; MDA were 2.04±0.92, 1.65±1.02, 1.01±0.12, F=4.250, P=0.040; SOD were 35.97±9.23, 55.99±18.97, 61.83±14.91, F=5.240, P=0.020; CAT were 31.42±16.27, 48.50±17.86, 75.95±13.09, F=9.720, P=0.002; GSH were 1.48±0.90, 3.54±1.88, 3.84±2.08, F=5.240, P=0.020). HE staining showed an increased intercellular space ratio in the I/R group (F=16.47, P<0.05). Immunohistochemistry staining showed that percentage of HMGB1 positive myocytes in control, I/R and I/R+ VSD group are 1.94%, 18.63% and 61.36%, respectively. There was significant difference among groups (F=853.886, P<0.01). A significantly inhibited HMGB1 expression by VSD therapy was also validated by the results of Q-RT-PCR (F=50.653, P<0.01) and Western blot (F=963.489, P<0.01).

CONCLUSIONThe results from the present research suggest that VSD may attenuate skeletal muscles I/R injury by increasing the cellular antioxidative stress reaction and inhibiting the reactive oxygen species as well as the inflammatory mediators.