| Objective: To observe the effect of propofol on Schwann cell proliferation and nerve function recovery after sciatic nerve injury in rats.Methods :One hundred healthy male SD rats aged 6-8 weeks were randomly divided into 4groups: sham operation group(S group),model group(M group),propofol group(P group)and fat emulsion group(F group),with 25 rats in each group.In group S,only the sciatic nerve was dissociated,and the incision was sutured.The model of right sciatic nerve injury was established in group M,group P and group F.Group P received continuous intraperitoneal injection of propofol 25 mg / kg for 7 days,once a day.Group M and Group F were injected with the same volume of normal saline and fat emulsion at the same time point as Group P.The general state,water intake,walking gait,toe amalgamation and the occurrence and recovery of heel ulcer were observed and recorded after operation at 1W,2W,4W and 8W.On the 7th day after the establishment of the model,5 rats in each group were randomly selected and killed,and about 1cm of the distal stump of the sciatic nerve was taken at the suture site of the injury.The proliferation and expression of Schwann cells was detected by immunofluorescence staining of Schwann cell specific markers S-100 and GFAP and the expression level of BDNF secreted by Schwann cells by Western Blot.Behavioral tests were performed at 1W,2W,4W and 8W after modeling,and the footprints of rats in each group were collected.According to the formula,the sciatic nerve functional index(SFI)and the wet weight recovery rate of gastrocnemius muscle were calculated to evaluate the repair of sciatic nerve injury.Results:1.General situation:All rats were successfully modeled without infection or death.The observation indexes of rats in S group had no significant change compared with those before operation.In the other three groups,the right lower limbs were paralyzed at 1W,the hind limbs could not be lifted,the joints could not be flexion,the toes could not be extended,and ulcers appeared in the heel;The rats in group P gradually recovered their claws and split toes at 3W～4W,and the ulcers began to heal.At 7-8 weeks,the toes converged slightly,which was obviously improved.The joint flexion disorder improved obviously,and the ulcer healed completely;However,the condition of lower limbs of rats in group M and group F did not improve at 2W,but gradually recovered at 5W-6W,ulcer began to heal,while some ulcers did not heal completely at 8W.2.SFI:There was no significant change in S group at about-10;Compared with S group,SFI in M group,P group and F group decreased significantly at 1W,2W,4W and 8W(P<0.05);At 4W and 8W,SFI in P group was significantly higher than that in M group and F group(P<0.05).3.S-100 and GFAP expression results:Compared with S group,the expression of S100 and GFAP protein increased in M group,F group and P group,The expression of S100 and GFAP in P group was significantly higher than that in M group(P<0.05);There was no significant difference between group F and group M(P>0.05).4.Western Blot:The expression of BDNF in S group was at a low level during the whole experiment;Compared with S group,the expression of BDNF in M group,P group and F group increased(P<0.05);Compared with M group and F group,the expression of BDNF in P group increased more significantly;There was no significant difference between group F and group M.5.Recovery rate of wet weight of gastrocnemius muscle:There was no significant change in group S,which was close to 1 in the whole course of the experiment;At 1W,2W,4W and 8W,compared with S group,the wet weight recovery rate of M group,P group and F group decreased,and the decrease of P group was the slightest;At 4W and 8W,the wet weight recovery rate of gastrocnemius muscle in P group was significantly higher than that in M group and F group(P<0.05).Conclusion: Propofol can promote the proliferation of Schwann cells and the recovery of nerve function after peripheral nerve injury. |
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