Objective:Toexplore the changes and mechanismofErythrocyte ImmunityFunction(EIF)in rats with Traumatic Brain Injury(TBI).Methods:HealthyWistar rat(sn=70)were divided intocontrol group(n=10)and TBI group(n=60)

model ofTBI were prepared and divided into mild group(n=30)and moderate to severe group(n=30).Red Blood Cell-C3b Receptor Rate(RBC-C3bRR)and Red Blood Cell-Immune Complex Rate(RBC-ICR)of rats with TBI were measured by methed of yeast fungus and the content of serum β-endophin(β-EP)was tested by radioimmunoassay.Results:Compared with the control group

RBC-C3bRR of rats with TBI decreased significantly while RBC-ICR andβ-EP increased significantly(P<0.05).Moreover

the moderate to severe group had more manifest difference than the mild group(P<0.05).β-endorphin was negatively correlated with RBC-C3bRR(r=0.698

P<0.05)and positively with RBC-ICR(r=0.744

P<0.05)in mild group;and negatively correlated with RBC-C3bRR(r=-0.835

P<0.05)and positively with RBC-ICR(r=0.729

P<0.05)in moderate to severd group.Conclusion:EIF in rats with TBI decreased significantly which demonstrated erythrocyte immune dysfunction was related with increasing of theβ-EP.