title: The gonadotropin secretion pattern in normal women of advanced reproductive age in relation to the monotropic FSH rise.
abstract: OBJECTIVE
  Women of advanced reproductive age are known to demonstrate subtle FSH elevations (monotropic FSH rise) while still retaining ovulatory function. The purpose of this study was to investigate the hypothesis that the physiologic basis for the monotropic FSH rise is an alteration in the secretion pattern of the GnRH pulse generator.
  
  
  METHODS
  The subjects were 11 normal women age 40-45 years who underwent 24 hours of frequent blood sampling in the follicular (EF) and/or midluteal (ML) phases of spontaneous menstrual cycles. The controls were 11 normal women age 20-25 years. The respective gonadotropin secretion patterns were analyzed for LH pulse frequency, mean LH and FSH levels, and LH pulse amplitude.
  
  
  RESULTS
  There were no differences between the groups for estradiol (E2) and progesterone when the respective cycle phases were compared. The 24-hour mean FSH level was significantly increased in the older women in both the EF and ML phases. There were no differences between the groups in either cycle phase for LH pulse frequency, LH pulse amplitude, and mean LH levels.
  
  
  CONCLUSIONS
  The results lend no support to the hypothesis that a slowing or other alteration of the GnRH pulse generator is the basis for the monotropic FSH rise in older ovulatory women. Other possibilities include the dynamics of E2 secretion or changes in FSH-modulating peptides (i.e., inhibin) in these women.
authors.affiliation: Department of Obstetrics and Gynecology, University of Washington School of Medicine, Seattle 98105, USA.
authors.forename: N A
authors.initials: NA
authors.lastname: Klein
authors.forename: D E
authors.initials: DE
authors.lastname: Battaglia
authors.forename: D K
authors.initials: DK
authors.lastname: Clifton
authors.forename: W J
authors.initials: WJ
authors.lastname: Bremner
authors.forename: M R
authors.initials: MR
authors.lastname: Soules
mesh_terms: D000328:Adult; D000367:Age Factors; D000375:Aging / Q000502:physiology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000378:metabolism*; D005498:Follicular Phase; D006801:Humans; D008183:Luteal Phase; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D008597:Menstrual Cycle / Q000097:blood*; D008875:Middle Aged; D010060:Ovulation; D012044:Regression Analysis
chemical_list: D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone