Abstract:

Abstract:Objective
To explore the effects of SB203580 on the expression of Homer1a and nerve cell apoptosis in hippocampus of rats after diffuse brain

injury（DBI）,and to clarify the mechanism of p38MAPK and Homer1a after DBI and the protective effect of SB203580.Methods 96 male

Sprague-Dawlley rats were divided into control group（n=24，only anesthesia without injury）,DBI group （n=40，Marmarou’s method

was used to establish DBI rat models）and SB203580 group(n=32,the rats were peritoneally injected with SB203580，0.01  μg•
kg^-1).The morphological changes of nerve cells of the rats  were observed under electron microscope;the positive cell rates of Homer1a

and phosphorylated p38MAPK in hippocampus CA1 of the rats were detected by immunohistochemistry and the apoptotic index(AI) of 

nerve cells of the rats was measured by TUNEL method.Results Compared with control group,the positive cell  rates of phosphorylated

p38MAPK and Homer1a in DBI group were increased at each time point (6，24，48,and 72 h after DBI)(P<0.05) and reached the peak at

24 h；the AI of nerve cells was  increased obviously （P<0.05） and reached the peak at 72 h. Compared with DBI group,the positive

cell rate of phosphorylated p38MAPK was decreased while that of Homer1a was increased and the AI of nerve  cells  was  decreased

obviously in SB203580 group（P<0.05）.Conclusion SB203580 can attenuate nerve cell apoptosis in hippocampus of the rats after DBI，

and the mechanism is related to the inhibition of p38MAPK activation and increasing the expression of Homer1a.

Key words: diffuse brain injury, mitogen-activated protein kinases, Homer1a, apoptosis