Objective:To investigate the effects of Tripterygium glycoside(TG) on Schwann’s cell apoptosis and major histocompatibility complex (MHC) of cold preserved sciatic nerve in rats. Methods:At 4℃

Wistar rat sciatic nerve segments were preserved in 0

200

400

800 mg/L TG solution(groups A

B

C

D)for 24 hours

3 days and 7 days. The sciatic nerves were observed by HE staining

the expression of Bcl- 2 was detected by immunohistochemical staining

and the apoptosis of Schwann’s cell by TUNEL. The Wistar rat sciatic nerve segments preserved for 24 hours were transplanted to the corresponding SD rats (groups A’

B’

C’

D’)

and group E’ received fresh nerve allograft. After allograft

the gross appearance and the pathology were observed at 1

2 and 4 weeks

and the expression of MHC-I

II of the allografts were detected by immunohistochemical staining. Results:The microstructure of sciatic nerves cold preserved were normal. The apoptosis of cold preserved sciatic nerves had no significant difference among the groups after preserved for 24 hours (P>0.05). After preserved for 3 days or 7 days

the expression of Bcl-2 in groups B and C were significantly higher than those in groups A and D P<0.05)

but there was no significant difference between group B and group C

between group A and group D (P>0.05);the apoptosis index in group A was significantly higher than those in groups B

C and D

higher in groups B and D than in group C(P<0.05)

but there was no significant differences between group B and group D(P>0.05). The adhesions between allografts and connective tissue

and the inflammatory cell infiltration in groups B’

C’and D’were better than those in groups A’and E’.The expression ofMHC-I

II ofthe allografts reached the peak at the first week. At the same time

the expression ofMHC-Ⅰ、Ⅱin groups B’

C’and D’were significantly lower than those in groups A’and E’

lower in groups C’and D’than in group B’

but there was no significant differences between group A’and group E’

between group C’and group D’(P>0.05). Conclusion:Certain concentration of TG can inhibit the apoptosis of Schwann’s cell and the expression of major histocompatibility antigen of cold preserved sciatic nerve in rats

and decrease rejection after nerve allograft.