Abstract: Objective To investigate the effect of taurine transporter in the process of protection of brain edema in rats with severe traumatic head injury. Methods A total of 24 Male Sprague-Dawley rats were randomly divided into 4 groups.Except the control rats (Group Sham), all other three groups were subjected to lateral fluid percussion head injury. The TBI(Traumatic brain injury) models (Group TBI) and surgical control rats (Group Sham) were injected with saline through caudal
vein after surgery, while the Taurine prevention and Taurine treatment models (Group Pre Tau and Group Tau) were injected with 120 g/L taurine solution before or after surgeries respectively. Water content in each brain, mRNA and protein expression of aquaporin 4 and taurine transporter in the injured rat brain hemispheres were all evaluated over the time course of the study (7 d) in each group. Results Compared with rats in Group Sham, water content in each brain increase, mRNA transcription and protein expression of AQP4 were both up regulated but the mRNA transcription and protein expression of TauT
were both down-regulated in rats in TBI group. Compared with rats in TBI group, brain water content, mRNA transcriptionand protein expression of AQP4 all decrease while mRNA transcription and protein expression of TauT all increase in rats in Pre tau and Tau groups. There is no statistical difference of TauT expression between rats in pre-tau group and Tau group.Conclusion Taurine exert its neuron protection role through draining water content from brain and down regulating expression of AQP4 but rising expression of TauT after TBI.

Key words: Taurine, brain injuries, membrane transport proteins, brain edema, aquaporin 4, rats, Sprague-Dawley, taurinetransporter transporter