The Effects Of In-utero Exposure To The Organophosphate Insecticide Dichlorvos On Leydig Cells In SD Rat

Objective The pregnant SD rats in this study were administered corn oiland dichlorvos by oral gavage from gestation day(GD) 12 to 17,its aim is toinvestigate probable mechanism of organophosphate insecticide dichlorvosinduced hypospadias by researching the influence of the organophosphateinsecticide dichlorvos on count ,immunohistochemistry stanning andultrastructure of leydig cells in male offsprings and detecting serumtestosterone level of adult male offsprings.Methods 21 conceived SD rats were divided into 7 groups at random:3in corn oil control group,3 in dichlorvos 1,4,8,16,20 and 24mg/kg/daygroup.Conceived rats were gavaged with 1 ml corn oil ,1,4,8,16,20 and 24mg/kg/day dichlorvos respectively from GD 12 to 17.After birth,the neonaterats were counted,examined for the penis appearance and meaeured bodyweight and anogenital distance(AGD).In addition,part testes were assayed byHE staining,immunochemistry staining and electron microscope.Remnantmale offsprings were bred until 90-day old,then serum specimens werecollected to measured testosterone level by radioimmunity and testes wereassayed by HE staining,immunochemistry staining and electron microscope.Results (1) Corn oil group had no hypospadias in male offsprings,while dichlorvos groups had 3,1 in dichlorvos 20mg/kg/day group and 2 indichlorvos 24mg/kg/day group.Dichlorvos can reduce the weight and shortenthe AGD of newborn rat,and this effect is dose-dependent.(2) There wasstatistic difference in count of leydig cell in male newborn rats between cornoil group and dichlorvos groups,dichlorvos cut down the count of leydig celland the severity is dose-dependent.But there was no statistic difference incount of leydig cell in adult male rats between corn oil group and dichlorvosgroups.(3) There was no statistic difference in testosterone level betweencorn oil group and dichlorvos groups.(4) Compared to corn oil group, smoothendoplasmic reticulum of leydig cell reduced in dichlorvos groups.Conclusion (1) Dichlorvos can induce hypospadias,reduce the weightand shorten the AGD of newborn rats.(2) Dichlorvos can cut down the countof leydig cell in male newborn rats,but there was no obvious influence onadult male rats.(3) Dichlorvos can reduce smooth endoplasmic reticulum andprobably degrade androgenic synthesis. (4) Dichlorvos had no obviousinfluence on testosterone level in adult male rats.