[Effects of transforming growth factor-beta 1 on the peripheral nerve regeneration of rats].

OBJECTIVE

To explore the effects of exogenous transforming growth factor-beta 1 (TGFbeta1) on peripheral nerve regeneration after the peripheral nerve injury and if TGFbeta1 regulates the expression of basic fibroblast growth factor (bFGF) in the anterior horn motoneurons of spinal cord during regeneration.

METHODS

Forty-eight rats were crushed on the right sciatic nerve and then randomly divided into 2 groups: TGFbeta1 group and NS group. In TGFbeta1 group, TGFbeta1 50 microL (0.1 microg/mL) was injected into the proximal nerve near to the crushed nerve and after the operation the injured leg was injected with equal TGFbeta1 whereas the NS was replaced in the NS group. The rats of each group survived for 3, 7, 14 and 21 days after the lesion. The bFGF expression in the anterior horn motoneurons of spinal cord was detected by immunohistochemistry (IHC). Semi-thin section and Fast Blue retrograde tracing were also performed with the rats surviving for 21 days to observe the regeneration of distal end in the injured right sciatic nerve.

RESULTS

The number of bFGF immunoreactive positive motoneurons in TGFbeta1 group was obviously higher than that of the NS group (P < 0.05). In the distal sciatic nerve of the rats treated with TGFbeta1, the number and diameter of regenerating myelinated axons and the thickness of myelinated sheath were more than those of the NS group (P < 0.05). The number of motoneurons in spinal cord and neurons in dorsol root ganglia (DRG) labelled with Fast Blue in the NS group was obviously lower than in the TGFbeta1 group (P < 0.01).

CONCLUSION

Exogenous TGFbeta1 plays an important role in promoting the peripheral nerve regeneration; TGFbeta1 up-regulates the bFGF expression in the anterior horn motoneurons of spinal cord during the peripheral nerve regeneration.