Effects of 2-hydroxyoestradiol-17β on plasma luteinizing hormone, follicle-stimulating hormone and prolactin, and nuclear translocation of pituitary oestrogen receptors in ovariectomized ewes

Abstract

The ability of oestradiol-17β (OE2) and 2-hydroxyoestradiol (2OH-OE2) to translocate pituitary oestrogen receptors to the nuclear compartment and to affect plasma concentrations of LH, FSH and prolactin was studied in ovariectomized ewes. Mean (± S.E.M.) nuclear oestrogen receptor levels (% of total pituitary oestrogen receptors) after intracarotid injections of 1.25 μg OE2, 400 μg 2OH-OE2 or vehicle were 8.7 ± 2.3, 16.9 ± 3.2 and 0.8 ± 0.1% respectively. Whereas 1.25 or 12.5 μg OE2 significantly lowered plasma LH and FSH, 400 μg 2OH-OE2 did not affect plasma LH or FSH levels. Injection of 4000 μg 2OH-OE2, however, significantly affected plasma LH and FSH. Plasma prolactin levels were not si..