Inhibin secretion after treatment with an LHRH agonist and subsequent ovarian hyperstimulation induced by FSH in the macaque (Macaca arctoides).
The effect of ovarian hyperstimulation with 'pure' FSH on serum concentrations of immunoreactive inhibin in macaques in which endogenous gonadotrophin secretion and ovarian activity had been suppressed by an LHRH agonist implant was studied. Four stump-tailed macaques were treated with an LHRH agonist implant in the early follicular phase of the cycle. After a transient stimulatory phase oestradiol secretion was markedly suppressed, and the rises in progesterone and inhibin observed after ovulation were absent. At 8 weeks after implant administration, when serum LH was only just detectable, FSH (Metrodin) was administered to the LHRH agonist-treated macaques once daily for 9 days (75 i.u. on Day 0, 35 i.u. Days 1-8). FSH treatment stimulated a marked increase in oestradiol and immunoreactive inhibin secretion in the absence of a rise in serum progesterone concentrations. Comparison of the FSH-induced pattern of inhibin secretion with the profile during the normal menstrual cycle showed that during the normal cycle inhibin is secreted into the peripheral blood almost exclusively during the luteal phase in the macaque, but stimulation of follicular development by exogenous FSH was associated with a rise in inhibin concentrations in the absence of ovulation. These results suggest that this non-physiological rise in inhibin may be one of the factors involved in the changes in endogenous gonadotrophin secretion which can occur during ovarian hyperstimulation.
Fraser
H M
HM
MRC Reproductive Biology Unit, University of Edinburgh, UK.
Smith
K B
KB
Reddi
K
K
Lunn
S F
SF
D000818:Animals; D002064:Buserelin / Q000494:pharmacology*; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D005498:Follicular Phase; D007265:Inhibins / Q000097:blood / Q000378:metabolism*; D008251:Macaca; D010053:Ovary / Q000187:drug effects / Q000378:metabolism*; D011374:Progesterone / Q000097:blood; D013268:Stimulation, Chemical
D011374:Progesterone; D004958:Estradiol; D007265:Inhibins; D005640:Follicle Stimulating Hormone; D002064:Buserelin