酵母源金属硫蛋白对慢性汞中毒小鼠排汞及肝脏损伤修复作用

目的:探讨两种具自主知识产权酵母源金属硫蛋白(metallothionein,MT)(MT-1、MT-2)对慢性汞中毒小鼠排汞及汞致肝脏损伤的修复作用。方法:慢性汞中毒模型通过实验小鼠自由饮用氯化汞去离子水溶液构建,经连续灌胃给予二巯基丙磺酸钠及不同剂量酵母源MT(0.16、0.40、0.80 mg/(kg·d))28 d后,测定实验小鼠体质量、肝脏脏器系数、血液及肝脏汞含量、4项血常规(白细胞计数、红细胞计数、血小板计数、血红蛋白含量)、肝功能指示指标并观察慢性汞中毒小鼠肝脏组织病变程度。结果:与模型对照组比较,各灌胃给药组小鼠体质量均不同程度提高,肝脏脏器系数显著下降(P0.05),血液及肝脏汞含量显著下降(P0.05),白细胞、红细胞、血红蛋白含量及血小板计数均有不同程度恢复,其恢复效果与剂量呈正相关。与模型对照组比较,各酵母源MT灌胃给药组小鼠血清谷丙转氨酶及谷草转氨酶含量均有所下降,且综合肝脏组织病理学染色切片结果,酵母源MT可修复汞中毒小鼠肝脏组织,使水肿肝脏细胞恢复其正常形态,减少细胞间炎性浸润现象,且两种酵母源MT修复受损肝脏的能力与剂量呈正相关,高剂量酵母源MT对受损肝脏的修复效果更佳。结论:综合各项检测结果,两种酵母源MT对慢性汞中毒小鼠具有良好的排汞及修复汞致肝脏损伤效果,且酵母源MT-1对慢性汞中毒小鼠排汞及修复受损肝脏组织的效果好于酵母源MT-2及二巯基丙磺酸钠。

Effect of Metallothionein from Yeast on Mercury Elimination and Liver Protection in Mice with Chronic Mercury Poisoning

Purpose: To evaluate the effect of two metallothioneins from yeast (MT-1 and MT-2) with self-owned intellectual property right on mercury elimination and liver damage repair in mice with chronic mercury poisoning. Methods: A mouse model of chronic mercury poisoning was established by giving the mice free access to deionized water containing mercuric chloride, and then the mice were orally administered with MT or dimercaptopropansulfonate sodium (DMPS) for 28 days. Body weight, liver index, blood and liver mercury levels, blood physiological and biochemical indicators and liver function were measured after the last administration. Results: Compared with the model group, the body weights of mice administered with MT were increased, the liver indexes and blood mercury and liver mercury levels were decreased significantly (P < 0.05), and white blood cell (WBC), red blood cell (RBC), platelet (PLT) and hemoglobin (HGB) levels were restored to different extents in a dose-dependent manner. Compared with the model group, the levels of serum ALT and AST in mice administered with MT were decreased. Based on these findings together with pathological examination, we found that MT could repair damaged liver tissues of mice with chronic mercury poisoning, restore liver cell edema to normal morphology, and reduce intercellular inflammatory infiltration and the effect was dose-dependent. Conclusions: Both metallothioneins from yeast have good efficacy in eliminating mercury and repairing damaged liver tissues in mice with chronic mercury poisoning, and MT-1 was superior to MT-2 and DMPS.