The Study Of The Effect Of Traumatic Brain Injury And Calcium Antagonist Nimodipine On Relative Changes Of Regional Cerebral Energy Metabolism In Rats

Objective 1. To study the acute changes of cerebral energy metabolism after traumatic brain injury in rats. 2. To explore the effect of nimodipine on regional cerebral energy metabolism in three different ways.Methods 40 female Wistar rats were randomly divided into control group(ct), sham group(sham), saline treatment group(saline), nimodipine treatment group injected peritoneally (0.2mg/kg)(np), nimodipine treatment group injected femarolly(2 g/kg)(nf), nimodipine treatment groups through microdialysis probe in three different doses , 0.1 g/kg (nml), 0.2 g/kg (nm2), 0.4ng/kg(nm3), respectively. The microdialysate concentration of glucose, lactae , pyruvate and L/P ratio were monitored continuously from 30min before , until 3h after a left parietal cortical contusion injury produced by the weight-drop technique. Saline and nimodipine were injected immediately in different ways , sham group was operated without treatment. Microdialysates were analysed on CMA600 Microdialysis Analyzer.Results 1. The concentrations of glucose adjacent to the brain contusion decreased immediately 15min posttrauma while lactate, pyruvate and L/P ratio increased. 45min after trauma, glucose decreased to the minimum level (0.052 0.001 mmol/L) but lactate and pyruvate elevated to 7.393 and 2.478 times , respectively. L/P ratio increased to 48.706 6.865 120min posttrauma. 2. The concentrations of glucose were not improved in np and nf groups, there were not significant difference between np, nf and ct groups. The concentrations of lactate and pyruvate as well as L/P ratio still above the sham group's level 3h posttrauma. 3. In nml and nm2 groups, the concentrations of lactate and L/P ratio decreased 30min posttrauma , which still above the sham group's level 3h posttrauma; glucose inmicrodialysate increased 30min after trauma , but still below the sham group's level 3h posttrauma. 4. In nm2 group, the concentrations of lactate and pyruvate as well as L/P ratio attenuated 15min posttrauma while glucose increased ; 45min after brain injury, the concentration of lactate was 2.514 times of pretrauma's. the concentration of pyruvate decreased to 1.894 times of pretrauma's 60min after trauma; the concentrations of glucose , lactate, pyruvate and L/P ratio 3h posttrauma were 0.094 0.005 mmol/L, 0.109 0.009 mmol/L, 10.610 0.192nmol/L, 10.300 0.843, respectively. There were not significant difference compared to sham group.Conclusions 1. The concentrations of lactate , pyruvate and L/P ratio elevated 15 minutes posttrauma while glucose decreased. 2. Nimodipine given through microdialysis probe can attenuate the concentrations of lactate , pyruvate and L/P ratio and increase interstitial glucose. 0.2|jg/kg may be the optimal dose.