锰对不同月龄大鼠脑纹状体细胞线粒体功能的影响

The Effects of Manganese on Mitochondrial Function of Brain in Rats at Different Age

[目的 ]观测不同价态的锰化合物 (包括二价锰和三价锰 )对大鼠脑组织纹状体部位细胞线粒体功能的影响及不同年龄的大鼠对锰化合物毒性的易感性差异。 [方法 ]分别选用 4个月和 1 8个月龄的Wistar大鼠作为研究对象 ,将大鼠分成不同的月龄组 ,每组又分成对照组和两个锰化合物组 ,腹腔注射染毒 (剂量按 6mg/kg)一个月后宰杀 ,提取动物脑组织纹状体部位细胞线粒体 ,测定线粒体复酶复合体 [complexⅡ及complex (Ⅰ +Ⅲ ) ]活性作为判断线粒体功能的指标 ,并同时观察染毒期间动物体重的变化。 [结果 ]不同鼠龄组中 ,锰化合物组线粒体功能均低于正常组。 1 8月龄和 4月龄大鼠complex (Ⅰ +Ⅲ )活性分别为 :正常组 (2 35± 1 0 3)、(2 66±0 1 1 )nmol/ (min·μg) ;二价锰组 (1 86± 1 0 8)、(2 0 4±0 1 2 )nmol/ (min·μg) ;三价锰组 (1 99± 1 0 1 )、(2 0 9± 0 1 6)nmol/ (min·μg) ;1 8月龄和 4月龄大鼠complexⅡ活性分别为 :正常组(2 58 70± 9 86)、(30 4 64± 2 0 1 8)nmol/ (min·μg) ;二价锰组 (2 0 8 45± 1 2 71 )、(2 4 7 0 0± 1 9 52 )nmol/ (min·μg) ;三价锰组(2 2 5 1 7±7 67)、(2 57 87±1 6 2 8)nmol/ (min·μg) ,且随着年龄的增高 ,对毒物的易感性也增加 ;

To examine differential toxic effects of Mn 2+ and Mn 3+ on mitochondrial function of neurons in striatum,we chose 4 and 18 months old Wistar rats as subjects,the different sensitivity of the two age groups was studied. The different age rats were divided into three groups as control,Mn 2+ and Mn 3+ treated groups. The last two groups received intraperitoneal injections of 6 mg/(kg·d) with different valent manganese for 30 days,respectively. The control group animals received the daily injections of the equivalent volume of sterile saline. Then rats striatum was removed and mitochondrial fractions extracted. Enzyme activities of the mitochondrial preparations were determined and animals weight changes were observed. The mitochondrial functions of the two manganese treated groups were both decreased compared with the control group (18 months old rats and 4 months old rats complex Ⅰ+Ⅲ activities are that respectively in nmol/min·μg:control group 2 35±1 03,2 66±0 11;MnCl 2 group 1 86±1 08,2 04±0 12;C 6H 10 O 6Mn·2H 2O group 1 99±1 01,2 09±0 16;18 months old rats and 4 months old rats complex Ⅱ activities are that respectively in nmol/min·μg:control group 258 70±9 86,304 64±20 18;MnCl 2 group 208 45±12 71,247 00±19 52;C 6H 10 O 6Mn·2H 2O group 225 17±7 67;257 87±16 28),and animal sensitivity to the manganese increased as their ages increased. The manganese also affected animals in weights (during this on month,18 months old rats weights had decreased in many grams as:control group 6 87±1 51,MnCl 2 group 28 75±4 55,C 6H 10 O 6·2H 2O group 37 5±10 58;4 months old rats weights had decreased in many grams as:control group 108 33±6 8,MnCl 2 group 62 35±11 74,C 6H 10 O 6Mn·2H 2O group 75 29±11 76). [Conclusion] Overdose manganese is harmful to mitochondrial function of striatum and this might be a potential cause of Parkinsons disease.