弥漫性颅脑损伤对大鼠海马一氧化氮合成酶活性及表达的影响

目的 :研究大鼠弥漫性颅脑损伤后海马结构一氧化氮合成酶 (NOS)活力及表达 ,分析海马不同亚区NOS活力变化与时间的关系。方法 :制作Wistar大鼠弥漫性脑损伤模型 ,并分对照组、假手术组及伤后6、12、24、48h组 ,于不同时间点获取脑组织 ;用NADPH 黄递酶 (NADPH d)组织化学法和免疫组化法检测NOS的活性及表达情况。结果 :NADPH d组织化学法显示 ,弥漫性脑损伤后 ,海马结构NOS阳性神经元数量在伤后6h最多 ,以后逐渐减少 ,伤后24、48h组明显低于假手术组 (P<0 05) ;免疫组化结果显示 ,在CA1、CA3区和齿状回 (DG) ,伤后24、48h组阳性细胞数均低于假手术组 (P<0 01)。结论 :大鼠弥漫性脑损伤后 ,可引起海马各区NOS的变化 ,该变化可能是造成脑组织继发性损害机制之一。

Effects of Diffuse Brain Injury on Activity and Expression of Nitric Oxide Synthase in Hippocampus of Rats

To investigate the effects of diffuse brain injury on activity an d expression of nitric oxide synthase(NOS) in hippocampus of rats and the rela tionship between the activity of NOS in subfields of hippocampus and time points Methods:All Wistar rat models with diffuse brain injury were randomly divided into 6 groups:a control group,a sham operated group and 4 other groups kille d at 6,12,24 and 48 hours after injury respectively NADPH d histochemistry a nd ABC immunohistochemistry were used to measure the activity and expression of NOS Results:With NADPH d histochemistry,the number of neuronal NOS positive cells in hippocampal formation was the highest at 6 hours after injury,then it gradually decreased The number in the group killed at 24 or 48 hours after inj ury was lower than that in the sham operated group (P<0 05) With ABC immuno histochemistry,the numbers in CA1,CA3 subfields and dentate gyrus in the group s killed at 24 and 48 hours after injury were lower than that in the sham opera ted group(P<0 01) Conclusion:After diffuse brain injury in rats,the activi ty of NOS changes in the subfields of hippocampus,which might be related to sec ondary brain injury