Effects of lactational bisphenol A exposure on the structure of testis and the expression of estrogen receptor α of weanling male mice

Objective To study the effects of lactational bisphenol A(BPA) exposure on the structure of testis and the expression of estrogen receptor α(ERα) of weanling male mice.Methods A total of 18 pregnant ICR healthy mice were randomly divided into six groups,high,moderate and low dose BPA groups(exposure doses were 50,5 and 0.01 mg/kg body weight),estrogen(E2) positive control group(exposure dose was 0.1 mg/kg body weight),corn oil negative control group and blank group(without treatment).The treatment was conducted after delivery,by gavage to maternal mice during postnatal days(PND) 2-21.The morphology changes of testis and the diameter of rat testis seminiferous tubular in different regions were determined,and immunohistochemistry and western blot were used to determine the expression of ERα.Results The seminiferous tubule showed regional aggregation and seminiferous tubules lumen increased significantly(P0.05) in the outer area of testis transverse of the high-dose,low-dose BPA groups.The average diameter of seminiferous tubules in the regional aggregation arrangement was longer than that of all seminiferous tubules from some testis transverse in negative group(P0.05).The expressions of ERα were decreased(P0.01,P0.05) in the testes of all BPA-treated groups,which were negatively correlated with BPA doses.Conclusion During lactational stage,exposure to a certain dose of BPA can influence the normal development of testicular cells,interfere with the arrangement and maturity of the seminiferous tubules and decrease the expression of ERα in the testicular tissue of male mice.