Postovulatory Concentrations Research Articles

Some sex hormone profiles are consistent over time in normal menstruating women: implications for sports injury epidemiology

PurposeIt is unclear whether sex hormone profiles obtained in two consecutive months are consistent within women. Month-to-month consistency in daily, nadir, peak and mean hormone concentrations during the early follicular...

Follicle suppression of circulating follicle-stimulating hormone and luteinizing hormone before versus after emergence of the ovulatory wave in mares

The effect of the ovarian follicles on plasma concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) before versus after the expected emergence of the ovulatory follicular wave was studied on Days 0 to 18 (Day 0 = ovulation) in four groups of mares (n = 6/group). In addition to a control group, all follicles ≥6 mm in diameter were ablated on Days 0.5, 6.5, or 12.5 in a herd of mares with reported emergence at 6 mm of the future ovulatory follicle on mean Day 10.5. Concentrations of FSH were not different between the Day-0.5 or Day-6.5 ablation groups and the corresponding controls. However, ablation on Day 12.5 resulted in an immediate FSH increase (group-by-day interaction, P < 0.003). For LH, ablation on Day 0.5 resulted in an interaction (P < 0.02), partially from lower (P < 0.05) concentrations on each of Days 15.5 to 18.0 than that in the controls, whereas ablation on Days 6.5 or 12.5 did not result in a significant group effect or interaction. Testosterone concentration, but not progesterone or estradiol concentration, was lower (P < 0.04) on Day 2 in the Day-0.5 ablation group than that in the controls. We inferred that follicles did not contain adequate FSH suppressors on Days 0.5 and 6.5 and that they were present only in the Day-12.5 ablation group or after the expected emergence of the ovulatory wave. The hypothesis of an association between low postovulatory concentrations of an ovarian steroid and low concentrations of LH after Day 15 was supported.

VALIDATING A COMMERCIALLY AVAILABLE ENZYME IMMUNOASSAY FOR THE DETERMINATION OF 17β-ESTRADIOL AND PROGESTOGENS IN THE FECES OF CHEETAHS (ACINONYX JUBATUS): A CASE REPORT

Fecal 17beta-estradiol and progestogens excretion was monitored in adult, female cheetahs (Acinonyx jubatus; n = 2), ZGG-12301 (born 3 April 1993), gonadotrophin treated and ZGT-3301, (born 19 August 1993), nontreated, for 120 days using commercially available plate enzyme immunoassay kits prepared for human serum or plasma. There were significant differences (P < 0.001) between baseline and peak concentrations of both hormone measures. Female ZGG-12301, which conceived, but this pregnancy resulted in an unobserved spontaneous abortion, showed no significant difference (P > 0.05) between baseline and gestation 17beta-estradiol values; fecal 17beta-estradiol excretion during pregnancy was statistically different (P < 0.001) from excretion during the nonpregnancy period. Baseline progestogen concentrations were different from pregnancy (P < 0.001) and postovulatory (P < 0.01) concentrations, and progestogen concentrations during pregnancy period were different (P < 0.001) from postovulatory concentrations. In the nontreated cheetah (ZGT-3301), basal and increased progestogen concentrations were statistically different (P < 0.01). On the basis of 17beta-estradiol excretory patterns, duration of the estrous cycle (x +/- SEM) was 13.2 +/- 2.2 days. These results suggest that the enzyme-linked immunosorbent methods reported in this study were capable of quantifying reproductive hormones in fecal extracts of cheetahs and could be a practical alternative to other enzyme-linked immunosorbent assays which require more complex procedures.

Ovarian follicles, ovulations and progesterone concentrations in aged versus young mares

The objectives of this study were: 1) to document age-related ovulation failure in mares and 2) to contrast the number of ovarian follicles, occurrence of ovulations, and postovulatory concentrations of progesterone in aged versus young mares. In Experiment 1, 4 of 10 aged (25- to 33-years-old) mares were anovulatory between July 1 and September 1, 1989. In Experiment 2, two of 25 aged (20- to 30-years-old) and none of 21 young (3- to 12-years-old) mares were anovulatory between February 1 and June 30, 1990. The average (± SEM) day of the first ovulation was later (P<0.05) for aged versus young mares (May 9 ± 7.1 vs April 25 ± 7.4 days, respectively). There tended (P<0.10) to be fewer 11- to 20-mm ovarian follicles in aged versus young mares (2.8 ± 0.2 vs 5.3 ± 0.1, respectively), but there was no difference (P>0.10) in the total number of ovarian follicles in aged versus young mares (21.0 ± 0.3 vs 26.1 ± 0.2, respectively) during the pooled periovulatory period of the first and second (single) ovulations. The number of ovulatory cycles during the study period was less (P=0.01) for aged versus young mares (2.2 ± 0.3 vs 3.2 ± 0.3). Plasma progesterone concentrations on Days 10 and 15 of the first ovulatory cycle were higher (P<0.05) in aged versus young mares.

Increased postovulatory plasma follicle stimulating hormone levels in the luteinized unruptured follicle syndrome: a role for inhibin?

In women who ovulated, the midcycle plasma follicle stimulating hormone (FSH) concentrations returned to basal concentrations within two days following the peak, whereas in women with a luteinized unruptured follicle, plasma FSH concentrations declined more slowly over a 4-5 day period. Since the peri- and postovulatory concentrations of plasma luteinizing hormone, prolactin, oestradiol-17 beta and progesterone were not significantly different between the two groups, we suggest that following the rupture of the Graafian follicle some substance in follicular fluid is resorbed from the peritoneal cavity which suppresses FSH secretion. Inhibin has biological properties which suggest it could be the substance involved.