OESTROGEN METABOLISM IN SHEEP MYOMETRIUM

Summary. Ovine myometrium obtained at 127 and 119 days of gesta-tion was incubated in vitro with [4-14C]oestrone and [6,7-3H2]oestradiol\x=req-\ 17\g=a\, and [4-14C]oestrone and [6,7-3H2]oestrone-3-sulphate, respectively. It was considered significant that oestrone was converted mainly to the much more potent oestradiol-17\g=b \ with very little transformation to the 17\g=a\-epimer. A high level of sulphatase activity was demonstrated by the formation ofoestrone and oestradiol-17\g=b \ from oestrone sulphate whereas the isolation of small amounts of oestrogen-3-sulphates also provided evidence of sulphotransferase enzyme activity in this tissue. These findings are discussed in connection with steroid metabolism by the sheep fetus and placenta and the possible significance of the meta-bolites isolated with regard to hormonal action in the myometrium