Study Of The Effect Of Taurine With Magnesium On Sd Rats Following With Acute Severe Traumatic Brain Injury

Object To investigate the changes of cell apoptosis rate and mRNA expression of genes related with apoptosis of neuroglia, to observe the alterations of ultrastructure of neuron and neuroglia, activity of mitochondrial respiration chain enzymes, cerebral blood flow and hemodynamics of SD rats after acute severe traumatic brain injury, and explore the effects of Taurine with Magnesium Sulfate on SD rats following with traumatic brain injury.Method This study includes two experimental parts, one is in vitro, the other is in vivo. Six hours hypoxia was performed for cultured neuroglia to make anoxic model, Tau with Magnesium and Tau-Mg were added immediately when hypoxia finished, then neuroglia was kept on culturing until 24h and 48h. Apoptosis rate of glia was detected by flow cytometry, mRNA expression level was measured by real-time PCR. Fifty Sprague-Dawley rats were randomly divided into five groups: sham group, TBI group, Tau group, Tau with Magnesium group and Magnesium group. All animals were subjected to severe injury (1.7-2.0atm) of left brain by lateral fluid percussion device except sham group, Tau and Magnesium were used for cure at once for seven days.Then all animals were killed. The ultrastructure of neuron and neuroglia were observed by electro-microscope, activity of mitochondrial respiration chain enzymes was measured by ultraviolet radiation(UV) spectrophotometer., cerebral blood flow and hemodynamics were tested with Laser Doppler and TEG Analyzer respectively.Result 1.Compared with normal group, cell apoptosis rate of hypoxia group markedly increased, early apoptosis rate of glia was remarkably minimized after treated with Tau and Magnesium for 48h. The Bax mRNA expression of hypoxia group for two time point was higher than normal group, and its expression level decreased for Tau and Magnesium group; there is no evidently statistical difference among groups for 24h Bcl-2 mRNA expression, but its level markedly increased after treated with Tau and Magnesium for 48h; the HIF-1αmRNA expression level of cure group was remarkably higher than hypoxia group. 2. The ultrastructure of neuron and glia were severe destroyed after TBI, including cell shrinkage and denaturalization, mitochondrion swelling and so on. Among the groups, Tau and Magnesium treatment shows the most effective function.3. Compared with sham group, activity of SDH decreased for all TBI groups, while compared with TBI group, Tau and Magnesium treatment improves SDH activity; but Tau and Magnesium had no effect on CCO activity;4. For hemodynamics change, Tau and Magnesium can postpone R and TMA, but minimize Angle, while Tau can make CI increase. Compared with sham group, cerebral blood flow of injured ipsilateral(left brain) observably descend, while CBF of right brain enhance, Tau and Magnesium is helpful to improve CBF, which is significantly increased than TBI group after treatment for 7d.Conclusion Hypoxia could initiate all kinds of cell apoptosis pathways, such as activating apoptosis gene Bax mRNA expression, but inhibiting Bcl-2 mRNA expression. The first part of our study about neuroglia suggested that Tau and Magnesium treatment is useful for keeping the balance between Bax and Bcl-2, which help to reduce early apoptosis rate, also it can promote HIF-1αmRNA expression, which is helpful for the adaptation to hypoxia. The second part of our study is about animals, which demonstrated the effect of Tau and Magnesium on TBI from different aspects. Ultrastructure of neuron and glia is the base of brain function, which is severe destroyed when suffering from TBI. Tau and Magnesium treatment can help neuron and glia keep almost normal. Mitochondrial respiration chain is the origin of source that is quite important for energy supply. Our study result showed that Tau and Magnesium may exert positive effect to protect from TBI. And cerebral blood flow and hemodynamics change also can't be ignored. Our study suggested that Tau and Magnesium treatment is beneficial to resume cerebral blood flow. Although it's not obvious for Tau and Magnesium to improve hemodynamics state, we could think it's a negative result. So it's necessary to do more work.