摘要
目的观察弓形虫感染对大鼠海马超微结构、海马组织超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量以及空间学习记忆能力的影响。方法将20只成年雄性SD大鼠随机分成2组:弓形虫感染组和健康对照组。弓形虫感染组每只大鼠腹腔注射纯化弓形虫速殖子107/ml×2 ml;健康对照组大鼠每只腹腔注射2 ml灭菌生理盐水。弓形虫感染9周后Morris水迷宫法测试各组大鼠空间学习记忆能力;应用黄嘌呤氧化酶法测定SOD活性;硫代巴比妥酸比色法测定MDA含量;透射电镜观察大鼠海马线粒体和突触结构的改变。结果 Morris水迷宫平均潜伏期弓形虫感染组大鼠(26.07±10.08)s,较对照组(13.46±5.43)s明显延长(P<0.05);弓形虫感染组大鼠海马SOD活性(49.74±4.44)NUI/mgprot,较对照组(58.19±6.83)NUI/mgprot降低(P<0.05);海马MDA含量感染组(4.48±0.65)nmol/mg-prot,较对照组(3.51±0.53)nmol/mgprot升高(P<0.05)。透射电镜观察弓形虫感染组大鼠海马细胞线粒体稍有扩张,粗面内质网、核糖体依然可见,但稍欠丰富;核膜基本清晰,无染色质聚集;线粒体膜尚基本完整,髓鞘轻度崩解,游离核蛋白体多。结论弓形虫感染可使大鼠海马自由基清除能力下降,氧化应激反应增强。
Objective To observe the impact of Toxoplasma gondii infection on the ultrastructure,superoxide dismutase（SOD） activity,and malondialdehyde（MDA） content in the hippocampus and spatial learning and memory.Methods Twenty adult male SD rats were randomly divided into 2 groups,a group infected with Toxoplasma and a control group.Each rat infected with T.gondii was intraperitoneally injected with 107/ml × 2 ml purified tachyzoites,and each rat in the control group was injected with 2 ml sterile saline.After 9 weeks,the learning and memory ability of rats was determined with the Morris water maze,SOD activity was determined with xanthine oxidase,MDA content was determined with thiobarbituric acid,and hippocampus mitochondria and changes in synaptic structure were observed with TEM.Results The average latent period in the Morris water maze was significantly longer（P0.05） for rats infected with T.gondii（26.07±10.08 seconds） compared to the control group（13.46 ± 5.43 seconds）.SOD activity in the hippocampus of rats infected with T.gondii（49.74 ± 4.44 NUI/mg prot.） was lower than in the control group（58.19 ± 6.83 NUI/mg prot.）（P0.05）.MDA content in the hippocampus of infected rats increased（4.48±0.65 nmol/mg prot.） compared to the control group（3.51±0.53 nmol/mg prot.）（P0.05）.TEM results showed that rats infected with T.gondii had morphologically normal hippocampal cells,slight expansion of mitochondria,rough endoplasmic reticulum,and visible ribosomes,albeit in smaller numbers.The nuclear membrane was clear and there was no chromatin aggregation.The mitochondrial membrane was basically intact.There was a mild breakdown of myelin and many free ribosomes.Conclusion T.gondii infection can decrease hippocampal scavenging and increase oxidative stress.
出处
《中国病原生物学杂志》
CSCD
2010年第12期908-911,共4页
Journal of Pathogen Biology
基金
江苏省卫生厅基金项目(No.X200739)
