Cell apoptosis and the expression of bcl-2and bax genes in neurons after traumatic brain injury in rats

Objective To investigate the relationship between the expression of bcl-2,bax genes and posttraumatic cellular apoptosis in various degrees of head injury in rats.Methods In the study the improved Feeney's free falling body injury model was adopted in100rats.The cell apoptosis was examined with TUNEL(terminal-deoxynucleotidyl transferase mediated nick end labeling)method and the bcl-2and bax gene exˉpression was detected with Immunohistochemisty method.Results The apoptosis Labeling Index(LI)was sigˉnificantly higher in injured groups than that in controls(P0.05)and the expression rate of bcl-2and Bax was also higher in the injured rats(P0.05).And in injured groups the ratio of bax/bcl-2was higher than that in control group(P0.05).These parameters in mild and moderate groups presented significant differences compared with the severe group.Conclusion The expression of bcl-2and bax may play an important role in posttraumatic cellular apoptosis of brain and the levels of bcl-2and bax were proportional to the degree of head injury.