论文部分内容阅读
目的研究苯并[a]芘(B[a]P)对大鼠海马形态学和突触的影响。方法初断乳雄性Wistar大鼠40只,随机分为空白对照组、溶剂对照组和3个染毒组(分别为6.25、2.5和1mg/kg体重),连续腹腔染毒13周(90d)。在染毒结束后,用电镜和光镜观察海马形态学改变。结果 HE染色对照组和B[a]P暴露各组大鼠海马神经元形态结构未见明显异常,电镜仅高剂量组偶有线粒体肿胀和核浓缩现象出现。高剂量组神经元突触PSD厚度和突触活性区长度均明显小于对照组和低剂量组(P﹤0.05),突触界面半径明显大于对照组和低剂量组(P﹤0.05)。结论低剂量B[a]P暴露对海马神经元形态和超微结构无明显影响,但B[a]P可能引起突触形态学的改变,降低突触的传递效率,因而影响学习记忆能力。
Objective To study the effects of benzo [a] pyrene (B [a] P) on the morphology and synapse of hippocampus in rats. Methods Forty weaned male Wistar rats were randomly divided into blank control group, solvent control group and three exposure groups (6.25, 2.5 and 1 mg / kg body weight respectively) for 13 weeks (90 days). At the end of exposure, the morphological changes of hippocampus were observed with electron microscope and light microscope. Results There were no obvious abnormalities in morphology and morphology of hippocampal neurons in HE staining control group and B [a] P exposure group. The phenomenon of occasional mitochondria swelling and nuclear condensation appeared only in high dose group by electron microscopy. The thickness of synaptic PSD and the length of synaptic active region of neurons in high dose group were significantly lower than those in control group and low dose group (P <0.05). The radius of synaptic interface was significantly larger than that in control group and low dose group (P <0.05). Conclusion Low dose B [a] P exposure has no effect on the morphology and ultrastructure of hippocampal neurons. However, B [a] P may induce the change of synaptic morphology and decrease the synaptic transmission efficiency, thus affecting learning and memory ability.