Inhibin A-subunit gene expression in the ovaries of immature female rats is stimulated by pregnant mare serum gonadotrophin.

We have used a bovine cDNA probe for the A-subunit of inhibin to demonstrate the presence of inhibin in the ovaries of immature female rats: the levels of mRNA were increased following treatment of the rats with pregnant mare serum gonadotrophin (PMSG), suggesting modulation by PMSG of ovarian inhibin synthesis at least at the level of transcription. Furthermore, we report the unexpected finding of significant levels of inhibin mRNA in the corpora lutea of mature female rats. No inhibin mRNA was demonstrable in the uterus or placenta.