ABSTRACT
Objective:To evaluate the effect of sufentanil on activation of Schwann cells after peripheral nerve injury in mice.Methods:Eighty healthy pathogen-free male Balb/c mice, aged 6-8 weeks, weighing 18-22 g, were divided into 4 groups ( n=20 each) using a random number table method: peripheral nerve injury group (group PNI), high dose sufentanil group (group H), medium dose sufentanil group (group M) and low dose sufentanil group (group L). The model of unilateral sciatic nerve transaction was established in ketamine-anesthetized mice.Immediately after establishment of the model, sufentanil 10, 5 and 2.5 μg/kg was injected intraperitoneally once a day for 3 consecutive days in H, M and L groups, respectively, while the equal volume of normal saline was given instead in group PNI.Sciatic function index (SFI) was calculated at 4, 8 and 12 weeks after establishment of the model.At 2, 4, 8 and 12 weeks, 5 mice in each group were sacrificed, and segments of the injuried ipsilateral sciatic nerve were removed for examination of the ultrastructure of the sciatic nerve (with a transmission electron microscope) and for detection of the expression of glial fibrillary acidic protein (GFAP) of sciatic nerve (by immunohistochemistry). Results:Compared with group PNI, SFI was significantly increased, and the expression of GFAP was up-regluated at each time point after establishment of the model in H and M groups ( P<0.05) and no significant change was found in SFI and GFAP expression after establishment of the model in group L ( P>0.05). Compared with group L, SFI was significantly increased, and GFAP expression was up-regluated in H and M groups ( P<0.05). There was no significant difference in SFI and GFAP expression between group H and group M ( P>0.05). The thickness of myelin lamellae was dense, and the proliferation of Schwann cells was not marked in H and M groups.The thickness of myelin lamellae was thin, and the proliferation of Schwann cells was marked in L and MO groups. Conclusion:The mechanism by which sufentanil improves repair after peripheral nerve injury may be related to promoting activation of Schwann cells in mice.