The effect of danazol on pulsatile gonadotropin secretion in women with endometriosis.
OBJECTIVE
To determine whether the effect of danazol on gonadotropin pulsatility was due to a direct effect of the drug or the suppression in the estradiol (E2) levels.


METHODS
Prospective analysis of serial blood samples at 10-minute intervals for 5 hours on days 3, 4, or 5 of the control cycle and 2 months after the start of danazol treatment.


METHODS
Tertiary institutional outpatient care.


METHODS
Six eugonadal women with minimal endometriosis.


METHODS
Oral administration of danazol, 200 mg three times daily.


METHODS
Gonadotropin mean levels, pulse frequency, and amplitude.


RESULTS
The mean level of E2 was the same in the control cycle as that during danazol treatment (170 pmol/L). Danazol administration resulted in a 16% increase in the mean luteinizing hormone (LH) pulse amplitude (95% confidence interval [CI] 6% to 26%, P less than 0.01), associated with a 20% decrease in LH pulse frequency (95% CI -71% to +31%, P = 0.37). There was a nonsignificant increase in follicle-stimulating hormone (FSH) pulse amplitude (2%, 95% CI -9% to +14%, P = 0.68) and in FSH pulse frequency (27%, 95% CI -4% to +58%, P = 0.08). The 22% decrease in the mean LH level (95% CI -85% to +12%, P = 0.13) and the 20% decrease in the mean FSH level (95% CI -53% to +37%, P = 0.33) were also not significant.


CONCLUSIONS
The increase in LH pulse amplitude represents a direct effect of danazol on the hypothalamic-pituitary axis.
Maouris
P
P
Queen Charlotte's Hospital, London, United Kingdom.
Dowsett
M
M
Edmonds
D K
DK
Sullivan
D
D
D000328:Adult; D003613:Danazol / Q000494:pharmacology*; D004715:Endometriosis / Q000503:physiopathology*; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D006801:Humans; D007986:Luteinizing Hormone / Q000378:metabolism*; D010507:Periodicity
D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D003613:Danazol