【摘要】 目的　探讨在硝酸镧的长期作用下 ,大鼠肝脏的形态变化、沉积肝脏中镧的后续效应及其作用机制。方法　给大鼠分别用硝酸镧 0 1、0 2、2 0、10 0、和 2 0 0mg/kg染毒 6个月 ,观察染毒6个月及停药 1个月大鼠肝体比变化 ,用常规组织学及透射电镜技术观察不同剂量的硝酸镧对大鼠肝脏形态结构的影响 ,运用电感耦合等离子体质谱法检测肝脏中镧含量。结果　染毒 6个月后 ,2 0 0mg/kg组雄鼠的肝体比明显高于对照组 ,染毒 6个月停药 1个月后 ,2 0 0mg/kg组大鼠肝体比恢复正常 ;染毒 6个月后 ,2 0 0mg/kg组大鼠肝脏门管区有炎细胞浸润 ,有些肝细胞胞质内有少量的脂滴 ,线粒体基质密度增高 ,有电子密度高的致密体及含致密颗粒的溶酶体 ,肝细胞核形态正常或轻度变形 ,雌鼠和雄鼠的肝糖原面积分别为 (2 6 1± 1 5 ) %和 (4 1± 1 4 ) % ,明显低于对照组的 (31 3±1 4 ) %和 (39 4± 0 9) % ,差异有显著性和非常显著性。染毒 6个月后停药 1个月 ,2 0 0mg/kg组大鼠肝脏门管区有少量炎细胞浸润 ,致密体数量少于染毒 6个月组大鼠。染毒 6个月后停药 1个月 ,各实验组大鼠肝脏中镧含量少于染毒 6个月相对应剂量组的大鼠。结论　 2 0 0mg/kg硝酸镧长期作用 ,对大鼠肝脏的结构有一定损害 ,但沉积于肝脏的镧可逐渐更多还原

【Abstract】 Objective To probe the effects of long-term oral administration of lanthanum nitrate [La （NO₃）₃] on morphological change in the liver, aftereffect of deposited La in the liver and their mechanism in rats. Methods Young Wistar rats were divided into two groups, one fed with 0.1, 0.2, 2.0, 10.0 and 20.0 mg/kg of La （NO₃）₃ for six months and the other for the control. Changes in ratio of liver to body weight were observed after exposure to La （NO₃）₃ at varied doses for six months and one month after six-month exposure, as well as morphology of the liver in the rats with routine histochemistry and transmission electron microscopy （TEM） technique. Content of La in the liver was measured with inductively coupled plasma-mass spectrometry （ICP-MS）. Results Ratio of liver to body weight was significantly higher in the male rats exposed to 20.0 mg/kg of lanthanum for six months than that in the control group. Ratio of liver to body weight restored to normal in the rats exposed to 20.0 mg/kg of La one month after six-month exposure. Infiltration of inflammatory cells in the portal region of the liver, small amount of fat drops in hepatocytic cytoplasm, increased density of mitochondria stroma, lysosome containing highly-electronic-density bodies and dense granules, normal nucleus and slightly deformed nucleus of hepatocytes could be found in the rats exposed to 20.0 mg/kg. Areas of the liver deposited with glycogen after six-month exposure to 20.0 mg/kg of La accounted for （26.1±1.5）% and （4.1±1.4）%, respectively for male and female rats, significantly lower than those in the control group [（31.3±1.4）% and （39.4±0.9）%, respectively] , with a statistical significance and very statistical significance, respectively. There was a little infiltration of inflammatory cells in the portal region of the liver one month after six-month exposure to 20.0 mg/kg of La, and amount of the dense bodies was lower in the rats exposed to La for six months. Liver contents of La in the rats of all experimental groups were lower one month after six-month exposure than those in the rats exposed for six months. Conclusions Exposure to a dose of 20.0 mg/kg La（NO₃）₃ for a long term could damage the liver structure to certain extent, but lanthanum deposited in the liver could be eliminated from the body gradually.更多还原