HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Am J Physiol Endocrinol Metab 292: E900-E906, 2007. First published November 22, 2006; doi:10.1152/ajpendo.00371.2006
0193-1849/07 $8.00

This Article Free upon publication Full Text Full Text (PDF) All Versions of this Article: 292/3/E900    most recent 00371.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by McCartney, C. R. Articles by Marshall, J. C. Search for Related Content PubMed PubMed Citation Articles by McCartney, C. R. Articles by Marshall, J. C.

Progesterone acutely increases LH pulse amplitude but does not acutely influence nocturnal LH pulse frequency slowing during the late follicular phase in women

The Center for Research in Reproduction; and Division of Endocrinology, Department of Internal Medicine, University of Virginia Health System, Charlottesville, Virginia

Submitted 26 July 2006 ; accepted in final form 19 November 2006

Progesterone (P) is the primary effector of LH (and by inference gonadotropin-releasing hormone) pulse frequency slowing in cycling women, but the time course of this action is unclear. We hypothesized that P administration to estradiol (E₂)-pretreated women would slow LH pulse frequency within 12 h. We studied eight normally cycling women in two separate cycles (follicular phase, cycle days 7–11). After 3 days of E₂ pretreatment (0.2 mg/day via transdermal patches), a 25-h blood sampling protocol (starting at 0800) was performed to define LH pulsatility. Oral micronized P (100 mg) or placebo (PBO) was administered at 1800 in a randomized, double-blind fashion, with treatment crossover occurring during a subsequent cycle. The 10-h mean P concentration increased from 0.6 ± 0.1 ng/ml before P (0800–1800) to 3.9 ± 0.3 ng/ml after P administration (2200–0800, P < 0.01). Ten-hour mean LH interpulse interval increased significantly after both P and PBO administration, with no significant difference between P and PBO. In contrast, mean LH, LH amplitude, and mean FSH increased significantly within 4 h of P administration, but not after PBO. We conclude that, in E₂-pretreated women in the late follicular phase, 1) nocturnal LH pulse frequency is not acutely (within 12 h) influenced by P administration; 2) an acute increase in P causes pronounced augmentation of gonadotropin pulse amplitude within 4 h; and 3) LH pulse frequency slows overnight during the second half of the follicular phase.

luteinizing hormone; gonadotropin-releasing hormone; follicle-stimulating hormone; estradiol; diurnal; circadian