摘要
目的 研究燃煤污染型氟中毒对大鼠睾丸B细胞淋巴瘤/白细胞-2 (B-cell lymphoma/leukemia-2,Bcl-2)、B细胞淋巴瘤/白细胞基因伴随蛋白x(Bcl-associated x protein,Bax)蛋白表达的影响,探讨氟中毒所致睾丸生殖毒害的机制.方法 将40只雄性SD大鼠按照体质量,采用随机数字表法分为4组:对照组,低、中、高氟组,每组10只.低、中、高氟组分别喂饲含氟20、40、60 mg/kg的饲料,对照组喂饲常规大鼠饲料(含氟1.3 mg/kg).每组大鼠在120、180d时股动脉放血法各处死5只,在处死前,观察氟斑牙的发生率及程度,收集大鼠24 h尿液,用氟离子选择电极法检测大鼠尿氟;取大鼠睾丸组织,用脱氧核糖核苷酸末端转移酶介导的缺口末端标记法(TUNEL)法检测大鼠睾丸生精细胞凋亡情况并计算凋亡指数(AI);采用免疫组化SP法检测Bcl-2、Bax蛋白表达水平.结果 在120、180 d,低、中、高氟组所有大鼠均出现不同程度的氟斑牙,而对照组未检出.在120、180 d,对照组、低、中、高氟组大鼠尿氟[(1.69±0.03)、(3.56±0.10)、(12.09±0.38)、(23.55±0.33)mg/L; (1.71±0.09)、(4.07±0.25)、(16.23±0.28)、(28.44±0.50)mg/L]均依次增高(P均<0.05);低、中、高氟组大鼠在180 d尿氟均高于120 d(P均<0.05).在120、180 d,对照组、低、中、高氟组大鼠睾丸生精细胞凋亡指数[(0.46±0.11)%、(8.83±1.64)%、(17.24±3.96)%、(44.21±7.85)%;(0.54±0.11)%、(10.41±2.70)%、(22.23±3.96)%、(49.62±4.77)%]依次增加(P均<0.05);低、中、高氟组,大鼠睾丸组织生精细胞凋亡指数在180 d均高于120 d(P均<0.05).在120、180 d,对照组、低、中、高氟组大鼠睾丸组织Bcl-2蛋白表达的平均光密度值(0.183±0.007、0.165±0.007、0.152±0.003、0.143±0.007;0.184±0.006、0.159±0.011、0.151±0.005、0.135±0.005)均依次降低(P均<0.05).在120 d,中、高氟组大鼠睾丸组织Bax蛋白表达水平(0.194±0.018、0.209±0.012)均高于对照组和低氟组(0.145±0.007、0.161±0.012,P均<0.05);在180 d,对照组、低、中、高氟组大鼠睾丸组织Bax蛋白表达水平(0.145±0.009、0.185±0.013、0.207±0.011、0.230±0.014)依次增多(P均<0.05).在120 d,对照组、低、中、高氟组大鼠睾丸组织Bcl-2/bax蛋白表达比值(1.264±0.044、1.028±0.096、0.788±0.060、0.688±0.064)依次降低(P均<0.05);在180 d,对照组、低、中氟组大鼠睾丸组织Bcl-2/bax比值(1.277±0.100、0.865±0.066、0.731±0.045)均高于高氟组(0.592±0.031,P均< 0.05),对照组高于中氟组(P<0.05).结论 燃煤污染型氟中毒可导致睾丸生精细胞凋亡指数升高、Bcl-2表达降低、Bax表达增强、Bcl-2/Bax比值降低;燃煤污染型氟中毒可能通过对凋亡相关基因调控参与雄性大鼠睾丸生殖损害机制.
Objective To study the effect of fluorine on expression of B-cell lymphoma/leukemia-2 (Bcl-2) and Bcl-associated x (Bax) protein in rat testis,and to reveal the mechanism of impaired male reproduction caused by endemic fluorosis of coal burning.Methods Forty male SD rats were randomly divided into 4 groups according to body weight with the method of random digits table:control group,low,moderate and high fluorosis groups.Low,moderate and high fluoride groups were fed with fluorinated food (20.0,40.0,60.0 mg/kg),and control group was fed conventional rat chow (fluorinated 1.3 mg/kg).After 120 and 180 days,the rats were sacrificed.Dental fluorosis was determined by observation and urinary fluoride was detected by fluorine ion-selective electrode.The apoptotic index of spermatogenic cell was measured by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL).The expression of Bcl-2 and Bax were measured by immuohistochemistry.Results At 120 and 180 days,low,moderate and high fluorosis groups were suffered from different degrees of dental fluorosis,the teeth of the control group was normal.At 120 and 180 days,the content of urinary fluoride was increased in turn in the control group,low,moderate and high fluorosis group [(1.69 ± 0.03),(3.56 ± 0.10),(12.09 ± 0.38),(23.55 ± 0.33) mg/L; (1.71 ± 0.09),(4.07 ± 0.25),(16.23 ± 0.28),(8.44 ± 0.50)mag/L; all P 〈 0.05].Urinary fluoride of low,moderate and high fluorosis groups at 180 days was higher than that of each corresponding groups at 120 days (all P 〈 0.05).At 120 and 180 days,the apoptotic indexes were increased in turn in the control group,low,moderate and high fluorosis groups [(0.46 ± 0.11)%,(8.83 ± 1.64%),(17.24 ± 3.96)%,(44.21 ± 7.85)%; (0.54 ± 0.11)%,(10.41 ± 2.70)%,(22.23 ± 3.96)%,(49.62 ± 4.77)%; all P 〈 0.05].At 180 days,the apoptotic indexes of low,moderate and high fluorosis groups were higher than those of each corresponding groups at 120 days (all P 〈 0.05).At 120 and 180 days,the expression of Bcl-2 were descended in turn in the control,low,moderate and high fluorosis groups (0.183 ± 0.007,0.165 ± 0.007,0.152 ± 0.003,0.143 ± 0.007,0.184 ± 0.006,0.159 ± 0.011,0.151 ± 0.005,0.135 ± 0.005,all P 〈 0.05).The expression of Bax of moderate and high fluoride groups (0.194 ± 0.018,0.209 ± 0.012) were significantly higher than that of the control and low fluorosis group (0.145 ± 0.007,0.161 ± 0.012) at 120 days (all P 〈 0.05).The expression of Bax were increased in turn in the control,low,moderate and high fluorosis groups (0.145 ± 0.009,0.185 ± 0.013,0.207 ± 0.011,0.230 ± 0.014,all P 〈 0.05).At 120 days,the Bcl-2/ Bax ratios were descended in turn in the control,low,moderate and high fluorosis groups (1.264 ± 0.044,1.028 ± 0.096,0.788 ± 0.060,0.688 ± 0.064,all P 〈 0.05).At 180 days,the Bcl-2/Bax ratio of control,low,moderate fluorosis groups (1.277 ± 0.100,0.865 ± 0.066,0.731 ± 0.045) was significantly higher than that of high fluorosis group (0.592 ± 0.031,all P 〈 0.05),and that of control group was significant higher than that of moderate fluorosis group (P 〈 0.05).Conclusions Endemic fluorosis of coal burning may leads to increased apoptotic index of rats' spermatogenic cell,increased Bax expression and decreased Bcl-2/Bax ratio.The mechanism of impaired male reproduction is possibly caused by regulation of the related apoptosis gene in the testis.
出处
《中华地方病学杂志》
CAS
CSCD
北大核心
2015年第4期254-259,共6页
Chinese Journal of Endemiology
基金
国家自然科学基金(81360097)
国际合作项目(2010DFB30530)
贵州省高层次人才基金(TZJF-2011年-27号)
贵州省省长基金(黔省专合字[2010181)
贵州省科技厅基金(黔科合LH字[2014]7126)