A Comparative Study Of The Protective Role Of Pre-treated Or Treated After Ischemia Onset With Calcium Channel Blocker On Rat Cerebral Ischemia Models

Part One The Protective Role of Pre-treated or Treated after Ischemia Onset with Calcium Channel Blocker on Rat Cerebral Ischemia ModelsObjective: To study the differences between the protective role of pre-treated and treated after ischemia onset with Nimodipine on the neurons in cerebral ischemia areas.Methods: The cerebral ischemic model of rat was made by occluding left middle cerebral artery according to Nagasawy and Zea Longa improvement method. The rats were pre-treated, treaded after ischemia onset or pre-treated plus treaded after ischemia with Nimodipine. The percentage of the infarction volume was calculated by TTC pigmentation. Results: The percentage of the cerebral infarction volume of pre-treated, treated after ischemia and pre-treated plus treaded after ischemia with calcium channel blocker Nimodipine was significant lower than that of control, and in the above three groups, the infarction percentage of the last group was lower than the anterior two. However, there was no significant difference between the percentage of pre-treated group and the one of treated after ischemia.Conclusion: There is stronger protective effect of pre-treated plus treated after ischemia with calcium channel blocker than pre-treated or treated after ischemia.Part Two The effects of Pre-treated and Treated after Ischemia Onset with Calcium Channel Blocker on Neuron Apoptosis of Rat Cerebral Ischemia ModelsObjective: To identify the potential mechanisms involved in the difference between the protective role of pre-treated and treated after ischemia onset with Nimodipine, their effects on neuron apoptosis of cerebral ischemia areas were studied.Methods: The cerebral ischemic model of rats was made by occluding left middle cerebral artery according to Nagasawy and Zea Longa improvement method. The rats were pre-treated, treaded after ischemia onset or pre-treated plus treaded after ischemia with Nimodipine. The level of Caspase-3 and Bcl-2 mRNA were measured by RT-PCR method.Results: The level of Caspase-3 mRNA was the highest in control group, and the expression was lower in treated after ischemia group, pre-treated group and pre-treated plus treated after ischemia group in turn. The level of Bcl-2 mRNA was reversed in the four groups.Conclusion: The anti-apoptosis effects take part in the protecitve role of nimodipine on cerebral ischemia, and pre-treated plus treated after ischemia brings the best results.