In:
Acta Endocrinologica, Oxford University Press (OUP), Vol. 112, No. 1 ( 1986-05), p. 64-70
Kurzfassung:
Abstract. The administration of glucocorticoids has been shown to be effective for the induction of ovulation in patients with anovulation. In the present study, we investigated the effects of a glucocorticoid on oestrogen-induced changes in the pituitary gland. A single ip injection of 10 μg oestradiol-17β (E 2 ) in ovariectomized and adrenalectomized rats resulted in a significant increase in pituitary weight and progesterone receptor (PgR) concentration. In these animals, serum LH level was initially suppressed and restored to control level 24 h after E 2 injection. However, 1 mg of dexamethasone (Dex) injected before E 2 , but not after E 2 administration, completely inhibited both the increases in pituitary weight and PgR concentration. The restoration of serum LH level 24 h after E 2 was also prevented. These antioestrogenic effects of Dex were blocked by ip administration of the synthetic antiglucocorticoid, RU486. Dex treatment alone did not have any effect on E 2 -induced changes in the dynamics of pituitary oestrogen receptor. Finally, E 2 -pellet implanted sc in ovariectomized and adrenalectomized rats for 7 days caused marked increases in pituitary weight and PgR concentration. A single ip injection of 250 μg clomiphene citrate (clomiphene) significantly reduced both the pituitary weight and PgR concentration in these animals, but 1 mg of Dex failed to have a similar effect. These results suggest that glucocorticoids antagonize E 2 effects on the pituitary by a mechanism different from antioestrogens such as clomiphene. These antioestrogenic effects of glucocorticoid may be involved in induction of ovulation in anovulatory women.
Materialart:
Online-Ressource
ISSN:
0804-4643
,
1479-683X
DOI:
10.1530/acta.0.1120064
Sprache:
Unbekannt
Verlag:
Oxford University Press (OUP)
Publikationsdatum:
1986
ZDB Id:
1485160-X
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