褪黑素对低硒饲料大鼠肝脏损伤的影响

目的　研究褪黑素对克山病病区低硒粮喂养的大鼠肝脏损伤的影响及其可能机制。方法　将SD大鼠分为3组 ,分别用低硒饲料、低硒饲料加硒、低硒饲料加褪黑素灌胃饲养 ,观察大鼠体质量增加情况。 12周时检测血Se、血GSH Px活性、肝组织MDA水平及肝组织病理损伤情况。结果　 12周时低硒组大鼠的体质量增加明显低于其他两组 ,血Se、血GSH Px活性较加硒组 (对照组 )显著降低 ,肝组织MDA及光镜下肝脏病变检出率均明显高于其他两组。加硒组与褪黑素组MDA无显著差异 ,光镜下两组均未见肝坏死。结论　褪黑素可预防克山病病区低硒粮引起的大鼠肝脏损伤 ,其保护作用可能与抗氧化机制有关。

Effects of melatonin on liver lesions in rats fed with low-selenium diet

Objective To study the effects of melatonin on liver lesions in Sprague-Dawley rats caused by low-selenium diet of Keshan disease areas and discuss the possible mechanism. Methods The rats were divided into three groups, which were fed with selenium-deficient diet of Keshan disease areas, diet rich in selenium and selenium-deficient diet with melatonin administered intragastrically, respectively, for twelve weeks. Then weight gain, selenium, GSH-Px activity, MDA level and liver lesions were examined in the rats. Results Weight gain of rats in low-selenium group was significantly lower than that of control group and melatonin group (P< 0.01). Blood selenium and GSH-Px activity of rats in low-selenium group were significantly lower those that of control group (P< 0.01). The content of lipid peroxidation product MDA of rats in low-selenium group was significantly higher than the other two groups (P< 0.01). Liver lesion occurred more frequently in low-selenium group than in the other two groups. Conclusion Melatonin can prevent rat liver from damage caused by low-selenium diet of Keshan disease areas because of antioxidative effect.