Study On Changes And Treatments Of Cold-induced Cerebral Edema And Neuronal Apoptosis In Rats

Objective: Taking the model of cerebral edema caused by frozen injury, this experiment greatly deals with measuring the alternation of brain water content, observing rules of neuronal apoptosis, studying the role of apoptosis in the brain injury, and applying tetramethyl-pyrazine to the treatment of frozen brain injury to have a further study on brain injury.Methods: Freezing the left parietal bone to -196 to cause a frozen injury, injected % Evans Blue (2ml/kg) into the tail vein 10 minutes later. Took swelling and shrinkage method to measure brain water content of in 2 hours, 6 hours, and 12 hours. Meanwhile, took TUNEL to observe neuronal apopstosis of the cortex and hippocampus in situ in 2 hours and 6 hours. Six hours after the frozen injury was done, tetramethyl-pyrazine was used to treat it. Then compared its effect to water content with the one treated with Dimethyl-Sulfoxide(0. 4g/kg), and observed its effect to apoptosis. Results:(1): The normal group and the sham-operated controls did not turn blue, but the frozen-injured groups did in different levels. (2): Compared with the controls, Water content of the frozen-injured brain increased obviously (p<0. 05) and had a tendency of increasing within 12 hours. There was no obvious difference between the 6-hour-injured group and 12-hour-injured group( P>0.05) .(3): Compared with the controls, neuronal apopstosis of injured brain tissue increased (p<0. 05). The apopstosis of 2-hour-injured group mainly appeared in the periphery of cortex surrounding the cold lesion and inside the cold lesion, while the apopstosis of 6-hour-injured group mainly appeared in the periphery of cortex surrounding the cold lesion and hippocampus.(4):Compared with the untreated group, the water content of the Tetramethy-pyrazine-treated and dimethyl-sulfoxide-treated groups decreased significantly(p<0.01), and dimethyl sulfoxide shows more ob6vious effect (p<0. 01). Compared with the untreated group, the neuronal apopstosis of dimethyl-sulfoxide-treated group decreased greatly (p<0.01)Conclus2ion:(1) : The making of the frozen-injured rat brain edema model succeeded. Vasogenic brain edema appeared at the early time.(2) : Neuronal Apoptosis appeared early after the frozen injury in the periphery of cortex surrounding the cold lesion, while necrosis simultaneously appeared in the central lesion.(3) : Tetramethy pyrazine has a significant effect on inhibiting apoptosis and relieving brain edema, but compared with dimethyl sulfoxide, the effect on relieving brain edema is slighter.(4): According to the clinic experience and this experiment, it can be concluded that except dehydrant pressure-releasing treatment in the early stage of the brain injury, anti-apoptosis medicine treatment should also be taken as early as possible. As an optional anti-apoptosis medicine, tetramethy pyrazine shows good effect. It is worth clinic trying and further studying.