Acute and subacute effects of naturally occurring estrogens on luteinizing hormone secretion in the ovariectomized rat: Part 1.

Journal Article (Journal Article)

Acute pretreatment of ovariectomized rats with genistein (G) alters gonadotropin-releasing hormone-(GnRH)-induced LH secretion in a fashion comparable to estradiol (E2). In the present studies we wished to (A) determine whether G can acutely inhibit tonic LH secretion by oral (po) or intravenous (iv) routes, (B) compare GnRH-induced LH responses following higher iv dose pretreatments with G or E2, and (C) determine effects of G or E2 pretreatments on progesterone (P)-induced secretion of LH. Mature Charles River CD rats were ovariectomized, and 2 to 5 weeks later intraatrial cannulae were placed. Serial blood samples were drawn and LH was measured by RIA. In experiments 1 and 2, G or E2 was administered acutely by gavage or iv, while in experiment 3, G and E2 were given subcutaneously (sc) oil 3 days prior to cannulation and sampling. Acute po administration of vehicle or G (0.1, 1.0, and 10 mg/kg BW) had no effect on tonic LH, while E2 suppressed LH at all doses (0.1, 1.0, and 10 mg/kg BW). Acute iv administration of vehicle and higher doses of G (1 and 10 mg/kg BW) had no effect on tonic LH, while the lowest dose G (0.1 mg/kg BW) and all doses of E2 (0.1, 1, and 10 mg/kg BW) suppressed tonic LH. In the iv-treated rats, GnRH-induced LH secretion was more profoundly suppressed by G at all doses than by E2.(ABSTRACT TRUNCATED AT 250 WORDS)

Full Text

Duke Authors

Cited Authors

  • Hughes, CL; Kaldas, RS; Weisinger, AS; McCants, CE; Basham, KB

Published Date

  • 1991

Published In

Volume / Issue

  • 5 / 2

Start / End Page

  • 127 - 132

PubMed ID

  • 1807543

International Standard Serial Number (ISSN)

  • 0890-6238

Digital Object Identifier (DOI)

  • 10.1016/0890-6238(91)90040-m


  • eng

Conference Location

  • United States