Effects Of Water-borne Bisphenol A On The Oxidative Stress,Metabolism,Sex Hormone And Histology Of Cyprinus Carpio

With the wide application of plastics and the rapid rise of related industries,Bisphenol A?BPA?is everywhere from drinking bottles,food packaging to medical devices.However,BPA may cause damage to the endocrine system,nervous system,and reproductive system of the organism.In this article,the experiment with C.carpio exposed to waterborne BPA were conducted,at the constant water temperature?25±1??,ethanol solubilization.Two series of experiments were carried out in this study:?:Acute exposure experiment:the tested fish were exposed to six BPA concentrations,i.e Cyprinus carpio at 0?control?,8.5 mg/L,9 mg/L,9.5 mg/L,10 mg/L,respectively to estimate the median lethal concentrations in 96 hours(96 h LC₅₀).?:Based on the result of 96 h LC₅₀,the BPA exposure concentraion in subacute toxicity experiment was designed as 0.5 mg/L,0.9 mg/L,1.8 mg/L,3.6 mg/L,7.2 mg/L,separate blank control group and ethanol control group.And then,the effects of different water-borne BPA concentrations on growth index,organ index,oxidative stress,resting metabolic rate,metabolic enzyme,and histology of C.carpio were studied.The main results were shown as follows:Experiment?:With the increase of BPA concentration in water,the mortality of C.carpio increased gradually,and mortality had a significant linear positive correlation with BPA concentration in water.Using the method of a straight line interpolation the values of 96 h LC₅₀0 of this C.carpio were estimated as 9.07 mg/L.Experiment?:1.With the increase of water exposure concentration,the BPA accumulation in the liver of C.carpio increased significantly,showing a dose-effect dependence.2.The effect of water-borne BPA on growth index of C.carpioThe male body length and body weight of the high-concentration BPA exposed group was significantly lower than that of the control group?p<0.05?.The body weight of the female C.carpio of the high-concentration BPA-exposed group was lower than that of the control group,but there was no significant difference.3.The effect of water-borne BPA on viscera index of C.carpioWith the increase of BPA exposure,the liver index of male C.carpio showed a downward trend.The 7.2 mg/L concentration group was significantly lower than that of the control group?p<0.05?.The female C.carpio liver index increased first and then decreased.Concentrations of 3.6 mg/L and 7.2 mg/L were significantly lower than those of control group?p<0.05?.After exposure to BPA in water,the kidney index of the female and male C.carpio of 7.2 mg/L was significantly higher than that of the control group?p<0.05?.After exposure to BPA in water,the male gonads index of 3.6 mg/L and 7.2 mg/L concentrations were significantly lower than those in the control group?p<0.05?.The female gonad index of 7.2 mg/L concentration was significantly higher than that of the control group.4.The effect of water-borne BPA on Sexual Hormones of C.carpioWith the increase of BPA concentration,the serum E₂ content of male C.carpio also gradually increased,serum E₂ content of 0.5 mg/L,0.9 mg/L,1.8 mg/L,3.6 mg/L,7.2 mg/L concentration group were significantly higher than the control group?p<0.05?;The serum T content gradually decreased.The serum T levels in the 0.9 mg/L,1.8 mg/L,3.6 mg/L,and 7.2 mg/L concentrations groups were significantly lower than those in the control group?p<0.05?.With the increase of BPA concentration,the serum E₂ content of female C.carpio gradually increased,and the serum E₂ content of the 3.6 mg/L and 7.2 mg/L concentrations groups were significantly higher than the control group?p<0.05?;The T content gradually decreased,and the serum T levels of the 0.5 mg/L,0.9 mg/L,1.8mg/L,3.6 mg/L,and 7.2 mg/L concentrations groups were significantly lower than the control group?p<0.05?.5.The effect of water-borne BPA on AKP activity of C.carpioWith the increase of BPA concentration,the AKP activity of the testis and ovary increased first and then decreased.The AKP activity of the testes at concentrations of0.9 mg/L,1.8 mg/L,3.6 mg/L,and 7.2 mg/L was significantly lower than that in the control group,the AKP activity of the ovarian at concentrations of 1.8 mg/L group was significantly higher than that in the control group?P<0.05?.6.The effect of water-borne BPA on the histology of C.carpioThe exposure of BPA in water induce alterations in the testis structure,with the increase of BPA exposure concentration,the number of spermatozoa decreased,and the structural damage of the testis was severer;The low concentration group compared to the control group,no significant change occurred,but the ovarian development rate was faster in the medium and high-concentration treatment group than in the control group.7.The effect of water-borne BPA on oxidative stress of C.carpioThe MDA content in the liver increased with the exposure concentration of BPA.The 1.8 mg/L,3.6 mg/L and 7.2 mg/L groups were significantly higher than the control group?p<0.05?.The activity of CAT enzyme in liver increased first and then decreased with the increase of BPA exposure concentration,3.6 mg/L,7.2 mg/L group were significantly lower than the control group?p<0.05?.The content of MDA in kidney increased with the increase of BPA exposure concentration,and it was significantly higher in the 3.6 mg/L and 7.2 mg/L groups than in the control group?p<0.05?.The activity of CAT enzyme in kidney increased first and then decreased with the increase of BPA exposure concentration.The 1.8 mg/L,3.6 mg/L,and 7.2 mg/L groups were significantly lower than the control group?p<0.05?.8.The effect of water-borne BPA on resting metabolic rate of C.carpioWith the increase of BPA exposure concentration,the resting metabolic rate of C.carpio increased first and then decreased.The resting metabolic rate of 7.2 mg/L group was significantly lower than that of other concentration groups and control groups?p<0.05?.The main conclusions suggested in this study were shown as follows:1.BPA can accumulate in the liver of C.carpio through the water body,showing a concentration-effect relationship.Therefore,the accumulation of BPA in the exposed liver of C.carpio can also be used as an index to evaluate the toxic effects of these substances in aquatic environments.2.The BPA has a certain inhibitory effect on the growth and development of C.carpio.Among them,the body length and body weight of male C.carpio have a significant decrease,and males are more sensitive to BPA than females.3.The liver,kidneys and gonads of C.carpio are damaged when exposed to waterborn BPA.The low concentration of BPA may cause stress to the liver of C.carpio.High concentrations of BPA may cause damage to the liver.Under the influenc;e of BPA,the C.carpio's kidney is affected,causing some damage;High concentration of BPA promotes ovarian development in females,but it can lead to atrophy of the male C.carpio,which may further damage the reproductive function of male C.carpio.4.BPA can interfere with the normal synthesis and metabolism of E₂ and T,causes abnormal levels of E₂ and T concentrations in C.carpio,and males are more sensitive than females.5.The AKP activity of male gonads in the high-concentration group was significantly lower than that in the control group,which may be the damage of the vas deferens membrane,indicating that the structure of the sperm membrane was damaged and affected the function of the reproductive organs.6.With the increase of BPA exposure concentration,the germ cells were inhibited and the testis structure was destroyed.However,the exposure of high concentrations of BPA accelerated the ovarian development.7.Exposure of water to BPA resulted in a large number of lipid peroxidation reactions in the liver and kidneys of C.carpio.Due to BPA stress,the lipid peroxidation reaction could not be properly coordinated,and the oxidation system was interfered by BPA and the oxidation process was inhibited.8.BPA exposure interferes with the metabolism of the C.carpio body.It may be that the tissue repair and poison purification activities of the C.carpio increase the metabolic energy consumption level;but the high BPA concentration causes tissue damage to the body.