摘要
目的观察燃煤型氟中毒对大鼠脑组织NO含量及NOS mRNA和蛋白表达的影响。方法健康SD大鼠24只,体质量100～120 g,按体质量随机分为3组,每组8只。对照组饲以常规饲料,低氟组和高氟组以氟病区燃煤烘烤的玉米为主要饲料(含氟量分别为11.30、104.20 mg/kg),来复制氟中毒大鼠模型,染氟时间为3个月。用氟离子选择电极法检测动物尿氟、骨氟、脑氟含量,观察大鼠海马CA1区神经元病理变化,用Biomias 2000图像分析系统测试大鼠海马CA1区神经元胞体平均面积、周长及平均灰度值,比色法测定脑组织NOS活性,硝酸还原酶法测定脑组织NO含量,蛋白印迹方法测定NOS蛋白水平;实时荧光定量PCR方法测定NOS mRNA水平。结果低、高氟组大鼠尿氟为(2.61±0.11)(4.39±0.13) mg/L,骨氟(2 734±137)(4 323±203) mg/kg,脑氟(1.00±0.08)(1.14±0.02) mg/kg;与对照组尿氟(1.59±0.10) mg/L、骨氟(1 399±152) mg/kg、脑氟(0.41±0.06) mg/kg比较,差异有统计学意义(P<0.05或P<0.01);尼氏染色显示,与对照组大鼠神经元平均灰度值(119.0±9.7)比较,染氟组大鼠均明显增加[低氟(153.0±8.9),高氟(159.4±2.9)];低氟组、高氟组大鼠脑组织总NOS活性[(8.57±2.40)、(11.49±3.10) kU/g]较对照组(16.80±3.20) kU/g显著性下降(P<0.05),高氟组大鼠脑组织NO含量(2.05±0.25)μmol/L较对照组(4.68±1.78)μmol/L显著性降低(P<0.05)。低氟组、高氟组大鼠脑组织NOS蛋白表达水平[(0.53±0.24),(0.82±0.28)]较对照组(0.17±0.02)显著增加(P<0.05/0.01),低氟组、高氟组大鼠脑组织NOS mRNA水平[(1.37±0.07),(1.38±0.08)]均较对照组(1.53±0.17)显著下降(P<0.05)。结论低剂量氟具有一定神经毒性,表现为食用燃煤型氟中毒病区燃煤烘烤的粮食低剂量、早期可导致动物脑氟含量增高,使大鼠海马CA1区神经元蛋白合成功能下降,脑组织NOS活性、NO含量、NOS蛋白及mRNA表达改变。
Objective To investigate the effect of coal-burning type fluorosis on the contents of NO and the expression of NOS at both mRNA and protein levels in rat brains.Methods Twenty-four healthy SD rats,weighting from 100 to 120 g,were randomly divided into three groups(8 in each).Control group was fed with normal diet,and low-and high-does fluoride groups were fed with corn polluted with high fluoride(fluoride was 11.30,14.20 mg/kg,respectively)during drying processes with local burning-coal from the areas of endemic fluorosis to established rat model of chronic fluorosis.During the third month experiment,fluoride contents in urine,bone and brain of the rats were detected with fluorine ion selective electrode,and neuro-pathological changes of the hippocampal CA1 area of the rats were examined with hematoxylin-eosin and Nissl’s staining and analyzed by Biomias 2000 Imaging Analysis System.The activities of NOS were examined with photometric method and contents of NO were examined with nitrate reductase method.The NOS at mRNA and protein levels were analyzed by real-time PCR and Western blotting,respectively.Results Compared with those of the control group(1.59±0.10)mg/L、(1399±152)mg/kg、(0.41±0.06)mg/kg of fluoride contents in urine,bone and brain tissue),the fluoride contents in urine(2.61±0.11)(4.39±0.13)mg/L),bone(2734±137)(4323±203)mg/kg),and brain tissue(1.00±0.08)(1.14±0.02)mg/kg)of the rats with fluorosis were increased markedly with significant differences(P<0.05 or 0.01 for all).The average grey values of neurons in the hippocampalCA1 of the rats were significantly increased in low-fluoride(153.0±8.9)and high-fluoride(159.4±2.9)exposed groups compared to those of the control(119.0±9.7).The activities of tN OS(8.57±2.40,11.49±3.10 kU/g)in brain tissues of the rats with fluorosis and contents of NO in brain tissues(2.05±0.25μmol/L)of the rats with high-fluoride group were significantly decreased as compared as controls(16.80±3.20 kU/g,4.68±1.78μmol/L).The protein of NOS in rat brains of l
作者
桂传枝
冉龙艳
官志忠
GUI Chuan-zhi;RAN Long-yan;GUAN Zhi-zhong(Department of Pathology and Molecular Biology,Guizhou Medical University,Guizhou Guiyang 550004,China)
出处
《中国地方病防治》
CAS
2019年第1期4-7,共4页
Chinese Journal of Control of Endemic Diseases
基金
国家自然科学基金(81460482)
高等学校博士学科点专项科研基金(新教师类联合基金
20115215120003)
