The Effect Of Taurine On Train Metabolism And Mitochondrial Respiratory Function In Rats Following With Severe Traumatic Brain Injury

Object The purpose of this research is to observe the effect of taurine on energy metabolism, mitochondrial respiratory function, mitochondrial reactive oxygen species (ROS), and mitochondrial ATP synthetical rate in rats following with traumatic brain injury. Methods:48rats were randomly divided into sham group, traumatic brain injury group (TBI) and taurine treating group,8rats in each group. The groups of TBI and taurine were subjected to severe traumatic injury of left brain by lateral fluid pressure device (4.5mm to anterior fontanelle,2.5mm to sagittal suture,in left brain). Then taurine group were injected traurin (200mg/kg) and the other groups were given saline through caudal vein immediately. Intercellular fluid in each group(each group contain3time points,1-3h,22-24h, and7d) in brain tissue were collected by using the method of microdialysis(4.5mm to anterior fontanelle,2.5mm to sagittal suture,3.5mm depth, in left brain), glucose, lactate, glycerol, pyruvate in the samples were measured using CMA600auto biochemistry analyzer, and calculate the ratio of lactate and pyruvate. Mitochondrial respiratory functions were detected by the method of Clark oxygen electrode. Mitochondria were extracted from lefe and right brain tissues respectively. Respiratory state III(R3) and respiratory state Ⅳ (R4) were detected, then calculate respiratory control rate(RCR) and the P/O ratio. Detected ROS by using the fluorometric method, and the rate of ATP synthesis by chemoluminescence method. Results:1-. Energy metabolism:(1) The level of glucose in hippocampus had no statistic differences in the three groups after traumatic brain injury; But the level of glucose were increasing significantly in TBT group with time goes.(2)The level of lactate was all higher in TBI group at the three time than those in sham group, and the differences had statistic significance, whereas,the level of lactate decreased in TBI group with time goes. Taurine could markedly decrease the content of lactate in24h, which had no significant difference to sham group.(3) After traumatic brain injury, the level of glycerol in damaged hippocampus had no statistic differences to sham group, but it decreased markedly in taurine group.(4)The level of L/P were all higher in TBI group at the3time point than those in sham group, and decreased with time goes. The level of L/P in taurine group were all lower than that in TBI group at3time point, but it was still markedly higher than that in sham group.2Respiratory function:(1) The level of R3. RCR, and P/O were lower and R4higher in TBI group in24h than those in sham group, the differences had statistic significance:The level of RCR increased and R4decreased markedly in taurine group in24h. The level of each vaule in right brain tissue had no statististic difference among three groups.(2) The level of R3, R4, RCR, P/O had recovered in TBI group in7d, but RCR was still lower than that in sham group.The level of RCR in taurine group increased in7d. Compared to sham group, each value in taurine all had no statistic difference.The level of each vaule in right brain tissue had no statististic difference among three groups.(3)ROS in Brain:In left brain mitochondria, ROS in TBI group increased in24h, and decreased in7d, but still higher than that in sham group; ROS in taurine group decreased with time gose. In right brain mitochondria, ROS in TBI group increased in24h, and decreased in7d; ROS in taurine group decreased with time gose.(4) ATP synthetical rate in brain mitochondria:In left brain mitochondria, ATP synthetical rate was lower in24h and7d in TBI group than that in sham group; ATP synthetical rate increased with time gose. In right brain mitochondria, ATP synthetical rate was lower in24h and7d in TBI group than that in sham group; taurine could increase ATP synthetical rate.Conclution:1、It may appear metabolism function disorder and taurine can adjust metabolism disorder after traumatic brain injury. Taurine can protect traumatic brain tissue.2、The mitochondrial respiratory function were impaired after traumatic brain(left brain) injury, but the right brain mitochondrial respiratory function didn’t change; Taurine could improve the state of mitochondrial respiratory function after traumatic brain injury.3、ROS in left brain mitochondria increased and influenced right brain after traumatic brain injury; Taurine can reduced the content of ROS in both left and right brain after trauma.4、ATP synthetical rate decreased in left brain mitochondria after trauma and influenced right brain mitochondria; Taurine could boost ATP synthetical rate, and could maintain nomal brain energy metabolism.