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目的探讨锰对大鼠海马损伤及性别差异。方法 64只SD大鼠随机分为对照组和3个Mn Cl2染毒组,雌雄各半,腹腔注射分别给予生理盐水(对照组)及7.5、15和30 mg/kg的Mn Cl21次/d,每周连续5 d,染毒4周,末次染毒后取脑组织及海马,每周测定动物体重,电感耦合等离子体质谱仪测定海马中锰含量,脑组织切片分别用苏木素-伊红(HE)染色及TUNEL法检测海马神经元损伤及凋亡。结果染毒1~4周后,雄性大鼠体重较对照组显著降低(P<0.05);而雌性与对照组比较差异无统计学意义(P>0.05),染毒4周后,雌、雄大鼠海马中锰含量呈剂量依赖性增长,均显著高于各自对照组(P<0.01),而性别间差异无统计学意义;HE染色及凋亡检测发现Mn Cl2剂量依赖性地引起海马神经元嗜酸性变及凋亡,且各剂量组,雄性神经元嗜酸性变及TUNEL阳性细胞数显著高于雌性(P<0.05)。结论锰可蓄积于大鼠脑海马组织,且性别间差异无统计学意义;锰可引起海马神经元变性及凋亡,且雄性较雌性更敏感,这与锰在海马的蓄积能力无关,可能存在其他毒效学因素。
Objective To investigate the damage and gender differences of manganese in hippocampus of rats. Methods Sixty-four SD rats were randomly divided into control group and three MnCl 2 -treated groups. The male and female rats were injected intraperitoneally with normal saline (control group) and MnCl 21 (7.5, 15 and 30 mg / kg) The rats were sacrificed for 4 weeks every week for 4 weeks. The brain and hippocampus were harvested after the last exposure. The body weight was measured weekly. The contents of manganese in the hippocampus were determined by inductively coupled plasma mass spectrometry. The brain sections were stained with hematoxylin and eosin (HE) ) Staining and TUNEL method were used to detect neuronal damage and apoptosis in hippocampus. Results After 1 to 4 weeks of exposure, the body weight of male rats was significantly lower than that of the control group (P <0.05), while there was no significant difference between female and control groups (P> 0.05). After 4 weeks of exposure, Mn in hippocampus increased in a dose-dependent manner, which were significantly higher than those in control group (P <0.01), but no significant difference was found between the sexes. HE staining and apoptosis assay showed that MnCl2 induced a dose-dependent increase in hippocampal neurons Eosinophilic changes and apoptosis, and the eosinophilic changes and the number of TUNEL positive cells in male neurons were significantly higher than those in females (P <0.05). Conclusion Manganese accumulates in the hippocampus of rats, and there is no significant difference between the sexes. Manganese can induce degeneration and apoptosis of hippocampal neurons, and the males are more sensitive than the females, which may not exist in manganese accumulation in the hippocampus Other toxicological factors.