CAJ | 학술논문

目的：研究在小鼠妊娠早期（前植入）体内暴露雌激素样甲氧滴滴涕（ MXC）或雌二醇的长期效应。方法妊娠1～3天孕鼠给予皮下注射1μg的雌二醇和5.0 mg的MXC（出现阴道栓为第0天）。妊娠对照组小鼠仅用载体芝麻油处理。检测胎仔数，出生后的生存率，出生时的性别比率和两种性别子代的肛门与生殖器间距离（ AGD），同时检测雌性子代阴道开放时间。采用放射免疫法检测雄性子代血清黄体生成素（ LH）、卵泡刺激素（ FSH）和睾丸酮（ T）含量。结果由于MXC暴露的子代可记录高的死亡率。暴露雌二醇或MXC不能改变出生时的性别比率，但是胎仔数减少。出生后21天雄性仔鼠AGD比对照组短，此变化在MXC处理组最为明显。在MXC暴露后雌性子代的AGD没有受到影响，但是雌二醇处理组雌性小鼠的AGD比对照组更长。植入前暴露雌二醇或MXC使更多的雌性小鼠在断奶时明显出现早熟阴道开放。 MXC处理组的雄性小鼠可降低血LH和FSH但是不改变睾丸酮水平。结论在前植入阶段暴露MXC或雌二醇造成在两性子代断乳后长期的性发育改变。 MXC处理也阻滞两性子代的发育和体重。
목적：연구재소서임신조기（전식입）체내폭로자격소양갑양적적체（ MXC）혹자이순적장기효응。방법임신1～3천잉서급여피하주사1μg적자이순화5.0 mg적MXC（출현음도전위제0천）。임신대조조소서부용재체지마유처리。검측태자수，출생후적생존솔，출생시적성별비솔화량충성별자대적항문여생식기간거리（ AGD），동시검측자성자대음도개방시간。채용방사면역법검측웅성자대혈청황체생성소（ LH）、란포자격소（ FSH）화고환동（ T）함량。결과유우MXC폭로적자대가기록고적사망솔。폭로자이순혹MXC불능개변출생시적성별비솔，단시태자수감소。출생후21천웅성자서AGD비대조조단，차변화재MXC처리조최위명현。재MXC폭로후자성자대적AGD몰유수도영향，단시자이순처리조자성소서적AGD비대조조경장。식입전폭로자이순혹MXC사경다적자성소서재단내시명현출현조숙음도개방。 MXC처리조적웅성소서가강저혈LH화FSH단시불개변고환동수평。결론재전식입계단폭로MXC혹자이순조성재량성자대단유후장기적성발육개변。 MXC처리야조체량성자대적발육화체중。
Objective To study the long-term effects of in vivo exposures to proestrogen meth-oxychlor ( MXC) or estradiol during early pregnancy ( preimplantation ) in mice.Methods Pregnant dams received either subcutaneous injections of 1μg of estradiol ( E2 ) and 5.0 mg of MXC on Days 1~3 of pregnancy ( vaginal plug=Day 0 ) .Pregnant control mice were treated with the vehicle only.Litter size, postnatal survival, sex ratio at birth, and anogenital distance ( AGD) in offspring of both sexes were examined , as well as vaginal opening in female off-spring .The concentrations of LH , FSH and testosterone ( T) in sera of the pregnant mice were determined using radioimmunoassay .Results High mortality rate was recorded in MXC-exposed offspring due to infanticide .Exposures to either E 2 or MXC did not change sex ratio at birth, but the litter size was smaller in the former group .On postnatal Day 21, male pups ex-posed to either E 2 or MXC at preimplantation stage exhibited shorter AGD than the controls , with the change most pronounced after MXC treatments .AGD in female offspring was unaffect-ed after MXC exposures, but E2 treatments produced longer AGD in the females than that recor-ded in the controls.Preimplantation exposures to E 2 or MXC also accelerated sexual maturation as significantly more females exhibited precocious vaginal opening at weaning .In males, MXC exposure during early pregnancy decreased serum LH and FSH , but not testosterone levels . Conclusion Exposures to MXC or E 2 at preimplantation stages cause long term alteration of sexual development during weaning in offspring of both sexes .Also, MXC treatments retarded both growth and weight of both sexes of offspring .