The effect of pulsed electromagnetic fields on the expression of transforming growth factor beta-1 after sciatic nerve injury / 中华物理医学与康复杂志

ABSTRACT

Objective To observe any effects of pulsed electromagnetic fields (PEMFs) on the expression of transforming growth factor beta-1 (TGF-β1) after sciatic nerve injury and to investigate the possible mechanism of any regeneration of the injured sciatic nerve.MethodsForty-eight SD rats were randomly divided into a PEMF treatment group,a model group and a normal control group with 16 rats in each group.The three groups were then sub-divided into 1 day,3 day,7 day and 14 day subgroups.The rats of the model and treatment groups were clamped to produce a sciatic nerve injury model.The treatment sub groups were exposed to a 9 mT PEMF at 14 Hz for 2 hours once daily for 1,3,7 and 14 days,respectively.The model group was given sham exposure and the normal control group was reared conventionally and not given any special treatment.The histological changes in the rats' sciatic nerves were observed under a light microscope after hematoxylin-eosin staining.Expression of TGF-β1 was detected by immunohistochemical methods.ResultsAfter 7 and 14 days of treatment,Wallerian degeneration of the sciatic nerve in the treatment group was more obvious than in the model group.The expression of TGF-β1 increased during the treatment process and reached a maximum at the 14th day after nerve injury.The expression of TGF-β1 had increased significantly in the model and treatment groups compared with the control group at all observation time points.At the 3rd,7th and 14th day after the operation,the expression of TGF-β1 in the treatment group was significantly higher than that in the model group. Conclusion PEMFs can accelerate Wallerian degeneration of peripheral nerves and can up-regulate the expression of TGF-β1 after sciatic nerve injury,at least in rats.