Time course of superoxide anion radicals generation in two ischaemia-reperfusion models: comparison between hindlimb replant model and isolated rectus femoris muscle model.

We examined differences in superoxide radical (O(2)(-)) production between a hindlimb replant model and isolated rectus femoris muscle model using rabbits. Using Japanese white rabbit hindlimbs, we made limb replant models (LR group: n = 10) and isolated rectus femoris muscle models (IM group: n = 8) by temporary 4-h clampings of femoral vessels and nutrient vessels, respectively. For sham control subjects, the same surgical procedures with no clampings in both models were done (Control-LR: n = 7, Control-IM: n = 6). The measurement of O(2)(-)was performed by our chemiluminescence (CLN) method. In both models, reperfused blood samples were collected before reperfusion, and 5, 15, 30 and 60 min after reperfusion, and CLN was measured. We defined the superoxide index (SI) in each individual specimen as post-reperfusion CLN/pre-reperfusion CLN. The time course of SI in the Control-LR group was significantly higher than that of SI in the Control-IM group (P< 0.05). There was no significant difference between the time course of SI in the LR group and that of SI in the IM group. Both the limb replant model and isolated muscle model are applicable for the evaluation of radical formation in the reperfused stage though there are potential differences between the two models caused by the surgical procedures themselves.