SERUM LEVELS OF FOLLICLE-STIMULATING-HORMONE AND LUTEINIZING-HORMONE AFTER SUBCUTANEOUS ADMINISTRATION OF HUMAN MENOPAUSAL GONADOTROPIN DURING PITUITARY SUPPRESSION

Objective - The present study investigated the pharmacokinetics of a s ingle subcutaneous dose of human menopausal gonadotropin (hMG) on seru m follicle-stimulating hormone (FSH) and luteinizing hormone (LH) conc entrations. Subjects and Methods - Six healthy female volunteers, aged 20-40 years, with regular lar menstrual cycles and normal endocrine p rofiles, who were not receiving any hormonal medication, were treated with the gonadotropin-releasing-hormone agonist buserelin to suppress endogenous gonadotropin release. One volunteer dropped out during trea tment. When the serum estradiol concentration had fallen to below 500 pmol/L, an injection of 150 IU hMG (Humegon(R)) was given subcutaneous ly. Immediately before injection and 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 15 , 20, 24, 48 and 96 hours after, blood samples were drawn for determin ation of FSH and LH concentrations. Results - The baseline FSH level w as 2.8 IU/L, and peak concentration (6.8 IU/L) was reached 12 hours af ter hMG injection (median values). Exogenous LH could not be measured because of the presence of endogenous LH. Discussion - The pattern of serum FSH concentrations after a single injection of hMG was found to resemble that seen after intramuscular hMG administration, although th e peak FSH value was reached somewhat later.