The experimental groups were injected(s.c.) with different doses of DES(dissolved in corn oil) during prepuberty [from postnatal day(PND) 22 to PND 35] and the control group with medium only.

• 于青春期前[出生后第22 d(postnatal day 22,PND22)至35 d(PND35)],实验组每日皮下注射相应剂量的DES,对照组仅注射溶媒。