Circulating nitrite/nitrate levels increase with follicular development: indirect evidence for estradiol mediated NO release.
Ovarian dysfunction as well as impaired release of endothelium-derived nitric oxide (NO) is associated with increased incidence of cardiovascular disease in postmenopausal women. Estrogen replacement therapy in postmenopausal women has a cardioprotective effect. Hence, using follicular development (FD) phase of the menstrual cycle of normal women (n = 7) and of patients undergoing in vitro fertilization (n = 16), we tested whether ovarian/sex hormones modulate NO-release. Levels of nitrite/nitrate (stable metabolites of NO), 17 beta-estradiol (E), progesterone (P), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were measured in serum collected during FD-phase. Serum nitrite/nitrate levels increased (p < .01) with the normal, as well as hormonally-induced FD and correlated with increases in serum E levels (r2 = 0.67; p < .01), but not with P, FSH and LH (p > .05). Post-ovulatory increase in P and LH levels decreased serum nitrite/nitrate levels (p < .05), even in presence of high E levels. In conclusion, nitrite/nitrate increase with follicular development, an effect that is potentially mediated by E induced NO release.
Rosselli
M
M
Department of Obstetrics and Gynecology, University Hospital Zurich, Switzerland.
Imthurm
B
B
Macas
E
E
Keller
P J
PJ
Dubey
R K
RK
D000328:Adult; D004958:Estradiol / Q000097:blood / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro; D005640:Follicle Stimulating Hormone / Q000097:blood; D005498:Follicular Phase; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D009566:Nitrates / Q000097:blood*; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000097:blood*; D010062:Ovulation Induction; D011374:Progesterone / Q000097:blood
D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone