RESUMO
Objective:To investigate the expression of GDNF mRNA on proximal end of sciatic nerve and T 12 L 1 spinal cord after sciatic nerve was cut in rats. Methods:The sciatic nerve of proximal end and spinal cord paralleling T 12 L 1 nerve root was taken respectively before and after sciatic nerve were severed. The level of GDNF mRNA on proximal end of sciatic nerve and spinal cord was observed and compared before and after sciatic nerve cut. Semi quantitative RT PCR method with ? actin as an inner consult was used to detect the expression of GDNF mRNA. Results:GDNF mRNA expression decreased by 10% 24 h after sciatic nerve was cut, 38% 7 d later, 45% 14 d and 52% 28 d in proximal end, while it decreased by 20%, 68%,80% and 85% on 1, 7, 14 and 28 d respectively in the spinal cord. Conclusion:The reduction of GDNF mRNA level on proximal end and homologous segmental spinal cord may be caused by losing the support of GDNF mRNA from the target tissue after sciatic nerve cut. This study provides a foundation for foreign GDNF to be used in treating SCI.