N-乙酰半胱氨酸对大鼠亚硒酸钠性白内障防治作用的实验研究

发布时间：2018-06-14 19:02

本文选题：N-乙酰半胱氨酸 + 亚硒酸钠　；参考：《郑州大学》2010年硕士论文

【摘要】： 研究目的观察N-乙酰半胱氨酸(N-acetylcysteine, NAC)对亚硒酸钠诱导的大鼠白内障的预防和治疗作用,为白内障的药物防治提供实验依据。对象与方法 (一)预防作用实验 10天龄SD大鼠30只随机分3组：正常对照组-1(Al组)：每日腹腔注射0.1ml/10g体重剂量的生理盐水,1次／日,共注射6天。亚硒酸钠组(B1组)：按3.46mg/kg(即20μmol/kg体重)颈部皮下注射亚硒酸钠,隔日一次,共注射3次。注射亚硒酸钠30分钟内,按0.1ml/10g体重腹腔注射生理盐水,共注射6天。 NAC预防组(C1组)：给10天龄SD大鼠按3.46mg/kg(即20μmol/kg体重)颈部皮下注射亚硒酸钠,隔日一次,共注射3次。注射亚硒酸钠30分钟内,按0.1ml／10g体重的剂量腹腔注射浓度为2mmol/L的试剂NAC,1次／日。共注射6天。 (二)治疗作用实验白内障模型制备：10天龄SD大鼠30只,按3.46mg/kg(即20μmol/kg体重)颈部皮下注射亚硒酸钠,隔日一次,共注射3次。将造模成功的大鼠随机分为病理对照组(15只)和NAC治疗组(15只) 病理对照组(B2组)：每日腹腔注射0.1ml/10g体重的生理盐水,共注射1月。 NAC治疗组(C2组)：按0.1ml/10g体重的剂量腹腔注射浓度为2mmol/L的试剂NAC,1次／日。共注射1月。正常对照组-2(A2组)：选预防实验中5只正常对照组大鼠,继续按0.1ml／l0g体重的剂量腹腔注射生理盐水,1次／日。共注射30天。大鼠睁眼后裂隙灯下定期观察大鼠晶状体的浑浊情况并拍照；最后一次注药后,分批处死大鼠,取出眼球,分离晶状体。光镜和扫描电镜下观察晶状体上皮组织学和超微结构的改变；免疫组化观察亚硒酸钠对晶状体上皮细胞中caspase-3的影响。生化方法测定亚硒酸钠对大鼠晶状体组织中超氧化物歧化酶(SOD)、丙二醛(MDA)含量的影响。结果小剂量隔日颈部皮下注射20μmol/kg亚硒酸钠溶液均可安全地诱导出大鼠白内障动物模型。 1.裂隙灯观察：亚硒酸钠组和病理对照组大鼠晶状体混浊情况持续性加重,在注药后第3天大部分晶状体核出现环状或尘埃状混浊,七天均形成典型的核性白内障,正常对照组晶状体均保持透明,未见混浊；预防组晶状体混浊程度低于亚硒酸钠组,而高于正常对照组；治疗组大鼠晶状体混浊程度与相应的病理对照组无明显差异。 2.光镜和扫描电镜观察：正常对照组晶状体组织结构基本正常,其他各组晶状体超微组织结构有不同程度的改变。其中预防实验中,亚硒酸钠组损伤最重,NAC预防组次之,正常对照组最轻,三组差别显著。治疗试验中,病理对照组和NAC治疗组无明显差异。 3.免疫组化观察：晶状体上皮细胞caspase-3在正常对照组呈阴性表达,平均光密度为250.319±2.347；NAC预防组呈弱阳性表达,平均光密度值为180.942±4.379,在亚硒酸钠组呈强阳性表达,平均光密度值为70.312±14.216,三组比较差异均有有显著性意义(P0.05)；在NAC治疗组和病理对照组均呈强阳性表达,平均光密度值分别为100.467±4.477,71.437±11.329,两组比较,差异无统计学意义(P0.05),但两组分别与正常对照组相比差异具有统计学意义(P0.05) 4.生化指标分析：NAC预防组晶状体中的SOD的活性高于亚硒酸钠组(P0.05),而低于正常对照组(P0.05)；NAC治疗组晶状体中的SOD的活性明显低于正常对照组,差异具有统计学意义(P0.05),而与相应的病理对照组比较无明显差异(P0.05)。NAC预防组晶状体中的MDA含量低于亚硒酸钠组(P0.05),而高于正常对照组(P0.05)。NAC治疗组晶状体中的MDA含量与相应的病理对照组比较无明显差异(P0.05)。结论 1.对SD大鼠皮下小剂量多次注射亚硒酸钠可成功制备硒性白内障模型。 2.亚硒酸钠可引起LECs凋亡 3.NAC可以通过提高晶状体组织中SOD的活性,减少MDA生成,降低caspase-3的活性来减轻亚硒酸钠引起的晶状体损伤。 4.NAC对早期白内障的发生、发展有一定的延缓和预防作用。 5.试剂NAC对于已经形成的硒性白内障无明显的治疗作用。
[Abstract]:Purpose of study

Objective To observe the preventive and therapeutic effects of N - acetyl cysteine ( NAC ) on sodium selenite - induced cataract in rats .

( 1 ) Preventive Effect Experiment

30 - day - old SD rats were randomly divided into 3 groups :

Normal control group - 1 ( Al group ) : 0.1 ml / 10 g body weight of physiological saline was injected intraperitoneally once daily for 6 days .

Sodium selenite group ( group B1 ) : The sodium selenite was subcutaneously injected at 3.46mg / kg ( that is , 20 渭mol / kg body weight ) in the neck of the neck , once daily for 3 times . After 30 minutes of sodium selenite injection , the saline was injected intraperitoneally with 0.1 ml / 10g body weight for 6 days .

NAC prevention group ( C1 group ) : 10 - day - old SD rats were given subcutaneous injection of sodium selenite at 3.46mg / kg ( that is , 20 渭mol / kg body weight ) , once daily for 3 times . After injection of sodium selenite for 30 minutes , a dose of 2 mmol / L of reagent NAC was injected intraperitoneally at a dose of 0.1 ml / 10 g body weight for 6 days .

( II ) Treatment effect experiment

The rats were randomly divided into pathological control group ( 15 rats ) and NAC treatment group ( 15 rats ) .

Pathological control group ( B2 group ) : 0.1 ml / 10g of normal saline was injected into the abdominal cavity every day for a total of 1 month .

NAC treatment group ( C2 group ) : A dose of 2 mmol / L reagent NAC was injected intraperitoneally at a dose of 0.1 ml / 10 g body weight for 1 time / day . A total of 1 month was injected .

Normal control group - 2 ( group A2 ) : 5 rats in normal control group were injected with normal saline at a dose of 0.1 ml / kg body weight for 30 days .

The opacity of the rat lens was observed and photographed under the slit lamp after open eyes .
After the last injection , the rats were sacrificed in batches , the eyeball was taken out , the lens was separated , and the changes of the epithelium and ultrastructure of the lens were observed under the light microscope and scanning electron microscope .
The effect of sodium selenite on caspase - 3 in lens epithelial cells was observed by immunohistochemistry . The effects of sodium selenite on superoxide dismutase ( SOD ) , malondialdehyde ( MDA ) content in lens tissue of rat lens were determined by biochemical method .

Results

The rat model of cataract was induced safely by subcutaneous injection of 20 渭mol / kg sodium selenite solution at low dose .

1 . Observation of slit lamp : The lens opacity in the sodium selenite group and the pathological control group was aggravated continuously . After the injection , most of the lens nuclei appeared cyclic or dust - like cloudiness , and typical nuclear cataract was formed on the seventh day , and the lens in the normal control group remained transparent , and the opacity was not seen ;
The degree of opacity in the prevention group was lower than that of the sodium selenite group , which was higher than that of the normal control group .
There was no significant difference between the degree of lens opacity and the corresponding pathological control group in the treatment group .

2 . Light microscope and scanning electron microscope observation : The structure of lens tissue of normal control group was basically normal , and the structure of the other groups had different degree of change . Among them , the injury of sodium selenite group was the most serious , NAC prevention group was the second , the normal control group was the lightest , and the three groups had significant difference . In the treatment trial , there was no significant difference between the pathological control group and NAC treatment group .

3 . Immunohistochemical observation showed that caspase - 3 was negative in normal control group , and the average optical density was 250.319 卤 2.347 ;
The average optical density was 180.942 卤 4.379 , and the mean optical density was 70.312 卤 14.216 . There was significant difference between the three groups ( P0.05 ) .
The mean optical density was 100.467 卤 4.477 , 71.437 卤 11.329 , and the difference was not statistically significant ( P0.05 ) .

4 . Analysis of biochemical indexes : The activity of SOD in the lens of NAC prevention group was higher than that of sodium selenite group ( P0.05 ) , but lower than that of control group ( P0.05 ) .
The activity of SOD in the lens of NAC treatment group was significantly lower than that of the control group ( P0.05 ) . The content of MDA in the lens of NAC prevention group was lower than that of the normal control group ( P0.05 ) . The content of MDA in the lens of NAC treatment group was lower than that of the normal control group ( P0.05 ) .

Conclusion

1 . The selenium - induced cataract model was successfully prepared by multiple injections of sodium selenite into SD rats .

2 . Sodium selenite can cause apoptosis of LECs

3 . NAC can reduce the lens damage caused by sodium selenite by increasing the activity of SOD in lens tissue , reducing MDA formation and decreasing the activity of caspase - 3 .

4 . NAC has a certain delay and preventive effect on the occurrence and development of early cataract .

5 . NAC has no obvious therapeutic effect on the selenium - induced cataract already formed .
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R776.1

【参考文献】