A highly potent analogue of LH-RH, d-Leu 6 des Gly 10 LH-RH-ethylamide was, used to study gonadotropin release after three repeated injections of a 25μg dose at 3-hourly intervals. Nine volunteers at different stages of the menstrual cycle and 14 patients with functional hypothalamic amenorrhea were investigated. LH secretion varied according to the functional state of the gonadostats, whereas FSH release did not show such differences. After repeated stimulation with the analogue, a tendency for diminished release of both gonadotropins was observed. Significant incremental changes of estradiol-17β levels occurred only after a decrease of pituitary responsiveness to further d-Leu 6 des Gly 10 LH-RH-EA stimuli was already evident. Therefore, it appears unlikely that estradiol-17β itself exerted a substantial negative feedback action on LH and FSH release in the authors experimental model. It is suggested that repeated administration of d-Leu 6 des Gly 10 LH-RH-EA leads to changes of pituitary receptor sensitivity.
|Original language||English (US)|
|Number of pages||11|
|Journal||International Journal of Fertility|
|State||Published - Jul 4 1980|
ASJC Scopus subject areas
- Obstetrics and Gynecology