Expression Of Bax, Bcl-2 And Caspase-3 In Spared Dorsal RootGanglion After Partial Dorsal Root Rhizotomy And Acupuncture

Objective: To explore the expression of Bax, Bcl-2 and Caspase-3 in spared dorsal root ganglion after partial dorsal root rhizotomy and acupuncture of adult cats.Methods: 20 adult cats were divided into 4 groups: normal control group; bilateral partial dorsal root rhizotomy and acupuncture 3^rd, 7^th and 14^th day groups (bilateral L1-L5, L7-S2 DRGs were transected, but L₆ DRG was spared, electro-needle stimulation was performed following bilateral partial root rhizotomy at the right side) . Animals survived for 3, 7 and 14 days after operation respectively. Bilateral L₆ dorsal root ganglia were made into frozen sections(20μm). Then sections were stained under the same condition using specific Bax (1:500), Bcl-2 (1:500) and Caspase-3(1:500) antibody by the immunohistochemistry ABC method. The distribution and the number of Bax. Bcl-2 and Caspase-3 positive neurons in bilateral spared DRG(L₆) were observed and counted. All data were analyzed30 by One-Way ANOVA. SNK-q test and paired-t test.Results: 1. The expression of Bax after partial dorsal rhizotomy and acupuncture in spared L₆ DRGIn normal adult cats, Bax immunoreactants were observed in partial large and medium-small sized neurons of L6 DRG The number of Bax positive total and medium-small sized neurons in spared DRG of the 3 day group increased apparently as compared with that of the normal control group (PO.05) but decreased apparently in the 14 day group and showed no significant difference when compared versus control (P >0.05 ) . Three days after acupuncture, the number of Bax positive total and medium-small sized neurons in acupuncture side had no significant change as compared with that of unacupuncture sidefT* >0.05). In 7 day group, Bax expression in neurons of DRG in acupuncture side decreased apparently as compared with that of unacupuncture side and returned to reference level and continued to 14 day.2. The expression of Bcl-2 after partial dorsal rhizotomy and acupuncture in spared I^DRGBcl-2 immunoreactants were observed in partial large and medium-small sized neurons of L& DRG. Bcl-2 expression among three operation groups in spared DRG had no difference compared with that of reference group (,P>0.05). Three days after acupuncture, the number of Bcl-2 positive total and medium-small sized neurons in acupuncture side had no significant change compared with that of unacupuncture side and reference group. In 7 day group, the number of Bcl-2 positive total and medium-small sized neurons in acupuncture side increased compared with that of unacupuncture side and continued to 14 day group.3. The expression of Caspase-3 after partial dorsal rhizotomy and acupuncture in spared L6 DRGCaspase-3 immunoreactivity was observed in partial large andmedium-small sized neurons of L6 DRG. The number of Caspase-3 positive total and medium-small sized neurons in spared DRG of all three operation groups increased apparently as compared with that of reference group (P<0.05) . The number of Caspase-3 positive total and medium-small sized neurons in acupuncture side of all three operation groups decreased significantly as compared with that of unacupuncrure side. The number of Caspase-3 positive total and medium-small sized neurons in acupuncture side of both 3 day and 7 day groups had no significant difference compared with reference group(f>0.05) and that of 14 day group decreased apparently as compared with reference group(P<0.05).4. The influence of partial dorsal rhizotomy and acupuncture on the expression of BaxN BcI-2^ Caspase-3 of different subpopulation neurons in spared DRGPartial dorsal rhizotomy and acupuncture on the expression of Bax^ Bc1-2n Caspase-3 of medium-small sized neurons in spared DRG had been mentioned, but had no significant influence on that of large neurons. Conclusion: Partial dorsal root rhizotomy mainly had an effect on the expression of Bax, Bcl-2 and Caspase-3 in medium-small sized neurons of spared DRG, especially from 3 day to 7day after the operation. The expression of Bax> Bcl-2 and Caspase-3 in spared DRG neurons were affected differently after acupuncture. Acupuncture mainly inhibited the expression of Bax and Caspase-3 but accelerated Bcl-2 expression in themedium-small neurons of spared DRG.