Necroptosis was found in a rat ischemia/reperfusion injury flap model

Background: Necroptosis is a new form of cell death that has been identified as a third pathway causing cell death. In this study, necrostatin-1 (Nec-1) was used to determine whether necroptosis exists in a rat ischaemia/reperfusion injury flap model. Methods: In this study, twenty male Sprague-Dawley rats were divided randomly into two groups: a control group (CTL group) and a Nec-1 group. Each abdominal skin flap underwent 3 h of ischaemia and then reperfusion. Fifteen minutes before and after reperfusion, phosphate buffer saline (PBS) was administered intraperitoneally to the CTL group, while Nec-1 was administered intraperitoneally to the Nec-1 group. Twenty-four hours after reperfusion, the whole flap was divided equally into S4 sections. Flap blood perfusion was measured. One sample was taken randomly from each row. Morphological changes, apoptosis, receptor-interacting protein-1 (RIP-1) expression and caspase-3 activity were observed and detected. The measurements between the two groups were compared with the independent t-test, and a P value of <0.05 was considered statistically significant. Results: Compared to flaps in the CTL group, flaps in the Nec-1 group showed longer survival rates, better blood perfusion and less inflammatory infiltration. The total flap area considered to have survived was 70.88 +/- 10.28% in the CTL group, whereas 80.56 +/- 5.40% of the area was found to he living in the Nec-I group (Nec-1 vs. cm, t=-2.624, P< 0.05). For some rows, there were significant differences in cell apoptosis between the two groups, the apoptosis index (AI) in rows 9 cm, 7 cm, 6 cm and 5 cm was significantly lower in the Nec-1 group than that in the CTL group (Nec-1 vs. CTL, P < 0.05). RIP-1 expression was much lower in the Nec-1 group than that in the CTL group in rows 5 cm to 9 cm (Nec-1 vs. CM, P< 0.05). No significant differences in caspase-3 activity were found. Conclusion: According to the results, necroptosis was present in a rat abdominal ischaemia/reperfusion injury flap model.