低蛋白摄入对燃煤型氟中毒雌性大鼠血清性激素及抑制素影响的动态观察

Dynamic variation of serum sex hormone and inhibin in rats with coal-burning fluorosis and low protein intake

目的动态观察低蛋白摄入对燃煤型氟中毒雌性大鼠血清性激素及抑制素浓度的影响。方法将120只断乳2周清洁级SD雌性大鼠随机分为4组,分别为对照(5.2 mg/kg氟+18 g/kg大豆蛋白质)组、低蛋白(5.2 mg/kg氟+9 mg/kg大豆蛋白质)组、氟中毒(96 mg/kg氟+18 g/kg大豆蛋白质)组、低蛋白氟中毒(96 mg/kg氟+9 mg/kg大豆蛋白质)组,每组30只。采用自由食用方式进行暴露,连续暴露180 d。分别于暴露60、120、180 d检测处于动情期雌性大鼠血清雌二醇(E_2)、孕酮(P)、睾丸酮(T)及抑制素(INH)浓度。结果单独低蛋白摄入60、120、180 d对雌性大鼠血清P浓度均无影响(P>0.05);单独氟染毒60 d对雌性大鼠血清P浓度无影响(P>0.05),染毒120、180 d可降低雌性大鼠血清P浓度(P<0.05);低蛋白和氟联合处理60、120、180 d对雌性大鼠P浓度的影响无交互作用(P>0.05)。单纯低蛋白摄入120 d可降低雌性大鼠血清E_2浓度(P<0.05),摄入60、180 d对雌性大鼠血清E_2浓度无影响(P>0.05);单纯氟染毒60 d可升高雌性大鼠血清E_2浓度(P<0.05),染毒120、180 d对雌性大鼠血清E_2浓度无影响(P>0.05);低蛋白和氟联合处理60、120、180 d对雌性大鼠血清E_2浓度的影响无交互作用(P>0.05)。单纯低蛋白摄入60、120、180 d对雌性大鼠血清T浓度无影响(P均>0.05);单纯氟染毒60、120、180 d可升高雌性大鼠血清T浓度(P<0.05);低蛋白和氟联合处理60 d对雌性大鼠T浓度的影响无交互作用(P>0.05),处理120、180 d对雌性大鼠T浓度的升高有交互作用,表现为协同作用(P<0.05)。单纯低蛋白摄入60、120、180 d可降低雌性大鼠血清INH浓度(P<0.05),单独氟染毒60、120、180 d可升高雌性大鼠血清INH浓度(P<0.05),低蛋白和氟联合处理60 d对雌性大鼠血清INH浓度无交互作用(P>0.05),处理120、180 d对雌性大鼠血清INH浓度的降低有交互作用,表现为协同作用(P<0.05)。病理学观察显示低蛋白和氟联合处理组卵巢组织损伤较严重。结论低蛋白和氟联合暴露可能通过降低血清中P、E_2、INH浓度和升高血清T浓度,从而促进雌性大鼠卵巢组织损伤。

Objective To observe the effect of low protein intake on serum sex hormone and inhibin content in rats with coalburning fluorosis. Methods A total of 120 weaned SD female rats were randomly divided into four groups,30 in each,control(5.2 mg/kg fluoride+18 g/kg soy protein) group,low protein(5.2 mg/kg fluoride+9 mg/kg soy protein) group,fluorosis(96 mg/kg fluoride+18 g/kg soy protein) group and low protein+fluorosis(96 mg/kg fluoride+9 mg/kg soy protein) group. Fluride expoxure was conducted through feeding fluoride-containing corn collected from coal-burning fluorosis area,for consecutive 180 days.Serum estradiol(E2),progesterone(P),testosterone(T) and inhibin(INH) concentrations were determined in estrus female rats at the 60 th,120 th and 180 th day of treatment,respectively. Results Alone low protein treatment for 60,120 and 180 d had no adverse effect on serum P concentration in female rats(P>0.05);The serum P showed significantly lower levels in female rats alone exposed to fluoride for 20 d and 180 d(P<0.05),and revealed no significant difference in female rats exposed for 60 d,compared with the control(P>0.05);There was no interaction between the low protein intake and fluoride exposure on serum P in female rats exposed for 60 d,120 d and 180 d(P>0.05). The serum E2 showed significantly lower levels in female rats alone exposed to low protein intake for 120 d(P<0.05),and revealed no significant difference in female rats exposed for 60 d and 180 d,compared with the control(P>0.05);The serum E2 also showed significantly higher levels in female rats alone exposed to fluoride for 60 d(P<0.05),and revealed no significant difference in female rats exposed for 120 d and 180 d,compared with the control(P>0.05);There was no interaction between the low protein intake and fluoride exposure on serum E2 in female rats exposed for60 d,120 d and 180 d(P >0.05). Alone low protein treatment for 60,120 and 180 d had no adverse effect on serum T concentration in female rats(P>0.05);The serum T showed significantly higher levels in female rats alone exposed to fluoride for60 d,120 d and 180 d respectively compared with the contorl(P<0.05);Synergistic interactions between low protein and fluoride on incresing serum T was found in female rats exposed for 120 d and 180 d respectively(P<0.05),no interaction was found in female rats jointly exposed for 60 d(P>0.05).The serum INH decreased in female rats alone exposed to low protein intake for60 d,120 d and 180 d,and increased in female rats alone exposed to fluoride,compared with the control(P<0.05);Synergistic interactions between low protein and fluoride on decreasing serum INH was found in female rats exposed for 120 d and 180 d respectively(P<0.05),no interaction was found in female rats jointly exposed for 60 d(P>0.05). More serious pathological damage was observed in ovary of rats in low protein+fluorosis group. Conclusion Combined exposure of low protein intake and fluoride may promote ovarian tissue damage in rats by decreasing serum P,E2,INH concentrations and increasing serum T concentrations.