ABSTRACT
Objective To investigate the alterations and molecular mechanism of neural cell apoptosis after frontal lobe sharp injury in infant rats.Methods Brain damage was induced by frontal lobe sharp injury.dUTP nick end labeling(TUNEL) method was used to detect cell apoptosis after brain injury,and immunohistochemistry was used to detect the expression of Bax,Bcl-2 proteins in and around the area of injury,respectively.Results The apoptosis cells were found as early as 1 hour and reached a peak at 24 hours post-injury,then gradually diminished until 120 hours when only few apoptosis cells presented.The expression of Bax and Bcl-2 proteins increased significantly 1 hour after frontal lobe injury.Bax protein reached its peak at 12 hours while Bcl-2 protein reached its peak at 1 hour post-injury.The ratio of Bax to Bcl-2 increased after lesion with peak at 24 hours,and then decreased thereafter.At 120 hours,very weak expression of Bax and Bcl-2 protein detected.There were few Bax and Bcl-2 positive cells in frontal lobe cortex in blank control and sham operation group.Conclusions Cell apoptosis exists after frontal lobe sharp injury in infant rats and the change of the number of apoptotic cells is correlated with time course of post-injury.The ratio of Bax to Bcl-2 may play a vital role in cell apoptosis.