Effect of Busulphan on the Developing Ovary in the Rat

Summary. Female rats were exposed to Busulphan on selected days between the 5th day of foetal life and Day 15 post partum, inclusive. The drug apparently had no effect on the foetal sex cells when administered to the pregnant female between Days 5 and 7 post coitum. Later in pregnancy a destructive action became rapidly more powerful. So far as the developing ovary is concerned it would seem that the action of Busulphan at this dose level, i.e. 10 mg/kg intraperitoneally, is confined to the precursor of the oocyte, namely the oogonium and that when these cells enter meiotic prophase on about the 17th day of foetal life there is a marked decrease in their sensitivity to the action of the drug. The effect of the treatment on fertility has also been studied.