Pulsatile LH-RH treatment induces a relatively low response of LH and FSH, while discontinuation enhances the response in women with amenorrhea of suprapituitary origin.
Five women with amenorrhea of suprapituitary origin were given intravenous injections of 10 micrograms LH-RH every 90 minutes for 4 days by means of a portable infusion pump. Immediately before and after this, the LH and FSH responses to a test dose of 100 micrograms LH-RH were measured. Four days after discontinuation of the treatment, so that LH and FSH could be measured, blood was sampled every 10 minutes for a period of 6 hours, during which 20 micrograms LH-RH was injected intravenously every hour. Finally, a test dose of 100 micrograms LH-RH was given. The whole procedure was repeated at least 6 weeks later, but this time hourly injections of 100 micrograms LH-RH were given 4 days after discontinuation of the pulsatile LH-RH treatment. Four days after the pulsatile LH-RH treatment was stopped, increased LH and FSH responses to LH-RH were observed. These could be reduced by 6 injections, given hourly, of either 20 or 100 micrograms LH-RH. Although the totally released amount of both LH and FSH did not differ between the two treatment regimens irrespective of the LH-RH dose used, the response of both gonadotropins to the LH-RH test dose after the hourly 100 micrograms LH-RH injections was significantly lower. This indicated that desensitization can be attributed, at least in part, to a lower responsiveness of LH and FSH to LH-RH when pulsatile LH-RH is given. Low responses during treatment with pulsatile LH-RH could not be related to higher concentrations of plasma estradiol. We conclude that women with amenorrhea of suprapituitary origin who are treated with pulsatile LH-RH have a low state of responsiveness to LH-RH, which can be caused by the presence of the LH-RH and might be attributed in part to desensitization by LH-RH. Removal of the LH-RH results in an enhancement of the responsiveness, as the pituitary gland might have recovered from this desensitization.
Lambalk
C B
CB
Department of Obstetrics and Gynecology, Academic Hospital, Vrije Universiteit, Amsterdam, The Netherlands.
Schoemaker
J
J
van Rees
G P
GP
van Dieten
J A
JA
D000328:Adult; D000568:Amenorrhea / Q000209:etiology / Q000503:physiopathology*; D004334:Drug Administration Schedule; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage; D006801:Humans; D007275:Injections, Intravenous; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D010902:Pituitary Gland / Q000503:physiopathology
D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone