Oestradiol-17β in testis and jugular venous plasma of intact and hemi-castrated prepubertal lambs and in jugular venous plasma of castrated prepubertal lambs

Abstract

An assay procedure comprising plasma oestrogen extraction into ether, separation of phenolic steroids (oestrogens) from non-phenolic matter, separation of oestrogens by chromatography on Sephadex LH20 and their radioimmunoassay (RIA), using oestrogen-specific antiserum, has shown sub-capsular, testis venous plasma, pooled from intact and hemi-castrated, prepubertal lambs to contain concentrations of oestradiol-17β in the range 80–120 pg/ml. By this same procedure, jugular plasma of these lambs contained significant ( P < 0.05) concentrations of oestradiol-17β ranging up to 4.2 pg/ml. Jugular venous plasma of castrated lambs collected at 4 and 9.6 weeks of age also contained significant concentrations of oestradiol-17β (0.46 pg/ml and 1.03 pg/ml respectively). It is concluded that the testis is an important source of the oestradiol-17β present in the systemic plasma of prepubertal lambs but that another source may also exist. The Sephadex LH20 chromatography and RIA revealed the presence in plasma, both testis and jugular venous, of significant concentrations of RIA- reactive material which had greater chromatographic mobility than oestrone (and oestradiol-17β).