Involvement of ovarian factors magnified by pharmacological induction of multiple follicular development (MFD) in the increase in Ca125 occurring during the luteal phase and the first 12 weeks of induced pregnancies

1995 ◽  
Vol 12 (4) ◽  
pp. 263-268 ◽  
Author(s):  
Anna Maria Paoletti ◽  
Gian Giacomo Serra ◽  
Valerio Mais ◽  
Silvia Ajossa ◽  
Stefano Guerriero ◽  
...  
Keyword(s):  
Luteal Phase ◽  
Follicular Development ◽  
Multiple Follicular Development

Inhibin secretion by the sheep ovary during the luteal and follicular phases of the oestrous cycle and following stimulation with FSH

1988 ◽  
Vol 117 (2) ◽  
pp. 283-291 ◽  
Author(s):  
C. G. Tsonis ◽  
A. S. McNeilly ◽  
D. T. Baird
Keyword(s):  
Luteal Phase ◽  
Venous Blood ◽  
Follicular Development ◽  
Follicular Phase ◽  
Pituitary Cells ◽  
Luteal Regression ◽  
Follicular Maturation ◽  
Prostaglandin F ◽  
Late Follicular Phase ◽  
Multiple Follicular Development

ABSTRACT The secretion of oestradiol and inhibin were measured during the follicular and luteal phase of the cycle by a sensitive bioassay using sheep pituitary cells in culture in four ewes in which the left ovary had been autotransplanted to the neck. On day 12 of the cycle, premature luteal regression was induced with an injection of 100 μg cloprostenol (prostaglandin F2α analogue; PG) and ovarian venous blood was collected every 4 h for 72 h. These same four ewes were infused in the ensuing cycle with NIH-oFSH-S14 at 10 μg/h for 48 h immediately after an injection of PG and sampled as above. During the luteal phase ( − 2 h before PG) both in the control and FSH-infused cycles the inhibin secretion rate (SR) was 27–45 units/min. After PG injection, the inhibin SR declined with time to reach 3·6–5 units/min at the onset of the LH surge (60 h after PG) in the control cycle. In contrast, in the following cycle infusion of FSH after PG injection caused a slight increase in the inhibin SR which then remained raised at 42–50 units/min for up to 60 h after PG. In the late follicular phase the oestradiol SR was greater in the FSH-infused than in the control cycles, indicating multiple follicular development. In the FSH-infused cycle the preovulatory surges of LH and FSH were markedly attenuated. These data demonstrate that (1) inhibin SR is high during the luteal phase suggesting that the sheep corpus luteum secretes inhibin, (2) in the control cycle inhibin SR declines during follicular maturation at a time when oestradiol SR is increasing but FSH levels are decreasing, and (3) exogenously administered FSH stimulates the secretion of inhibin from the ovary during the follicular phase. J. Endocr. (1988) 117, 283–291

Induction of multiple follicular development and superovulation in the olive baboon, Papio anubis

1991 ◽  
Vol 20 (6) ◽  
pp. 308-314
Author(s):  
Thomas J. McCarthy ◽  
Jeffrey D. Fortman ◽  
Melinda L. Boice ◽  
Asgerally T. Fazleabas ◽  
Harold G. Verhage
Keyword(s):  
Follicular Development ◽  
Papio Anubis ◽  
Olive Baboon ◽  
Multiple Follicular Development

The effect of acute immuno-neutralisation of inhibin in ewes during the early luteal phase of the oestrous cycle on ovarian hormone secretion and follicular development

1995 ◽  
Vol 145 (3) ◽  
pp. 479-490 ◽  
Author(s):  
B K Campbell ◽  
B M Gordon ◽  
C G Tsonis ◽  
R J Scaramuzzi
Keyword(s):  
Luteal Phase ◽  
Follicular Development ◽  
Experimental Period ◽  
Ovarian Follicles ◽  
Passive Immunisation ◽  
Follicle Development ◽  
Ovarian Steroid ◽  
Blood Samples ◽  
Steroid Secretion ◽  
Antibody Titres

Abstract Ewes with ovarian autotransplants received either inhibin antiserum (10 ml i.v. raised in sheep against recombinant 32 kDa human inhibin; n=6) or sheep serum (10 ml i.v.; n=5) on day 3 of the luteal phase with additional daily injections (1 ml i.v.) from 48 h after the initial bolus until day 13. Jugular and ovarian venous blood samples were taken 4-hourly over days 2–13 of the luteal phase. Blood samples were also taken at more frequent intervals (every 10–15 min for 2–3 h) to examine pulsatile secretory responses from the ovary to endogenous and gonadotrophin-releasing hormone-induced (150 ng i.m.) LH pulses on days 4, 6, 8, 10 and 12 of the luteal phase. Plasma FSH levels, ovarian steroid secretion and ovarian follicular development were measured. The ovarian follicle population was estimated daily by real time ultrasound scanning. Immunisation against inhibin resulted in a 3- to 4-fold increase (P<0·001) in plasma FSH levels within 8 h with levels remaining elevated over controls for 6–7 days. Within 24 h of immunisation there was an increase in the number of small ovarian follicles (P<0·05) and by 3 days after treatment immunised ewes had 4–6 large ovarian follicles/ewe with this increase in the total number of large follicles being maintained for the rest of the experimental period (P<0·05). Mean ovarian oestradiol secretion during intensive bleeds was not different from controls 24 h after immunisation, but by 3 days after immunisation it was elevated 4- to 5-fold (P<0·001) over controls with this increase being maintained throughout the experiment. Similar responses to immunisation against inhibin in androstenedione secretion were observed although mean androstenedione secretion was not elevated until 7 days after treatment. In vitro antibody titres in immunised ewes remained elevated but declined steadily (P<0·001) over the experimental period. We conclude that the initial stimulation of follicle development and ovarian steroid secretion following passive immunisation against inhibin can be attributed to increased blood FSH. However, the fact that with time FSH declined but increased follicle development was sustained, despite maintenance of high circulating antibody titres, suggests that on a longer term basis inhibin immunisation may stimulate ovarian function by interfering with the modulation of follicle development by inhibin at an ovarian level. Journal of Endocrinology (1995) 145, 479–490

Case report: Multiple follicular development associated with herbal medicine

1994 ◽  
Vol 9 (8) ◽  
pp. 1469-1470 ◽  
Author(s):  
D.J. Cahill ◽  
R. Fox ◽  
P.G. Wardle ◽  
C.R. Harlow
Keyword(s):  
Case Report ◽  
Herbal Medicine ◽  
Follicular Development ◽  
Multiple Follicular Development

The antagonistic effect of exogenous LH pulses on FSH-stimulated preovulatory follicle growth in ewes chronically treated with a gonadotrophin-releasing hormone agonist

1990 ◽  
Vol 127 (2) ◽  
pp. 273-283 ◽  
Author(s):  
H. M. Picton ◽  
C. G. Tsonis ◽  
A. S. McNeilly
Keyword(s):  
Luteal Phase ◽  
Follicular Development ◽  
High Amplitude ◽  
Follicle Growth ◽  
High Concentration ◽  
Continuous Administration ◽  
Releasing Hormone ◽  
Low Concentrations ◽  
Gonadotrophin Releasing Hormone ◽  
The Mean

ABSTRACT The hypogonadotrophism model induced by the chronic administration of gonadotrophin-releasing hormone (GnRH) agonist was used to investigate the effects of different concentrations of FSH with or without LH pulses on the stimulation of follicular development in the ewe. Continuous administration of an agonist (buserelin) by osmotic minipump to thirty-six Welsh Mountain ewes from the early luteal phase for 5 weeks resulted in a sustained suppression of the plasma concentration of FSH and inhibited the pulsatile release of LH. The inhibition of gonadotrophin secretion was due to the desensitization and/or down-regulation of pituitary gonadotroph function, since the agonist-treated animals showed no response to a challenge of 1 μg GnRH. During week 6 of agonist treatment, ewes were infused with either 4-hourly pulses of ovine LH (9 μg/pulse), low concentrations of ovine FSH (3 μg/h) or high concentrations of FSH (9 μg/h) alone or with 4-hourly pulses of LH. After 5 days of gonadotrophin infusion, there was no difference between the mean number of follicles per ewe from the animals treated with LH alone, low concentrations of FSH with or without LH pulses or the high concentration of FSH alone compared with the mean number of follicles from control ewes on day 8 of the luteal phase. Infusion of the high concentration of FSH alone stimulated the development of an increased number of large oestrogenic follicles (follicles > 2·5 mm in diameter and secreting > 3·7 nmol oestradiol/h in vitro) compared with control ewes. The addition of high-amplitude LH pulses to the infusion of the high concentration of FSH prevented follicles developing beyond 2·5 mm in diameter, but doubled the number of small follicles (≤2·5 mm) present in the ovaries. These results show that normal follicular development can be induced by physiological concentrations of FSH alone in the absence of pulsatile LH release. The addition of high-amplitude LH pulses antagonized this stimulatory effect of FSH on follicle growth in the ewe. Journal of Endocrinology (1990) 127, 273–283

1 PROGESTERONE AS THE DRIVING REGULATORY FORCE BEHIND SERUM FSH CONCENTRATIONS AND ANTRAL FOLLICULAR GROWTH IN CYCLIC EWES

2010 ◽  
Vol 22 (1) ◽  
pp. 159
Author(s):  
T. E. Baby ◽  
P. M. Bartlewski
Keyword(s):  
Treatment Group ◽  
Estrous Cycle ◽  
Luteal Phase ◽  
Follicular Development ◽  
Serum Levels ◽  
Time Frame ◽  
Corpora Lutea ◽  
Research Station ◽  
Follicular Growth ◽  
Follicular Waves

Ovarian antral follicles in sheep grow in an orderly succession, producing typically 3 to 4 follicular waves per 17-day estrous cycle. Each wave is preceded by a transient increase in circulating FSH concentrations. The mechanism controlling the number of recurrent FSH peaks and emerging follicular waves remains unknown. During the ewe's estrous cycle, the time between the first 2 FSH peaks and days of wave emergence is longer than the intervals separating the ensuing FSH peaks and follicular waves. The prolonged inter-peak/inter-wave interval occurs early in the luteal phase when low levels of progesterone are secreted by developing, or non-fully functional, corpora lutea. The purpose of the present study was to determine the effect of varying progesterone (P4) levels on circulating concentrations of FSH and antral follicular development in sheep. Exogenous P4 (15 mg per ewe i.m.) was administered twice daily to 6 cycling Rideau Arcott × Dorset ewes from Day 0 (ovulation) to Day 4 (the mean duration of the inter-wave interval); 6 animals served as controls. Follicular growth was monitored in all animals by daily transrectal ultrasonography (Days 0 to 9). Jugular blood samples were drawn twice a day from Day 0 to 4 and then daily until Day 9 to measure systemic concentrations of P4 and FSH. The first FSH peak post-ovulation was detected on Day 1.4 ± 0.2 and 4.0 ± 0.2 in treated and control ewes, respectively (P < 0.05). The next FSH peak(s) occurred on Days 3.4 ± 0.3 and 5.2 ± 0.2 in the treatment group and on Day 5.5 ± 0.3 in controls. Consequently, the treatment group had, on average, 3 follicular waves emerging on Days 0, 3, and 6, whereas the controls produced 2 waves emerging on Days 0 and 5 (P < 0.05).We then retrospectively analyzed and compared daily serum concentrations of P4 and FSH obtained in cyclic Western White Face ewes (Columbia × Rambouillet) that had 3 (n = 10) or 4 (n = 19) follicular waves per cycle. Mean P4 concentrations were greater (P < 0.05) in sheep with 4 waves per cycle compared with their counterparts, which had 3 waves of follicular growth. Interestingly, the ewes with 3 waves exceeded (P < 0.05) all animals with 4 follicular waves in mean serum FSH concentrations on Days 0 to 2, 6 to 7, and 9 to 15 post-ovulation. In summary, creation of mid-luteal phase levels of P4 in metestrus shortened the time to the first post-ovulatory FSH peak in ewes, resulting in emergence of one more follicular wave compared with control animals during the same time frame. The ewes exhibiting 4 waves of follicular emergence had greater serum levels of P4 but lower FSH concentrations compared with sheep with 3 waves per cycle. Therefore, progesterone appears to be a key endocrine signal governing the control of periodic increases in serum FSH concentrations and the number of follicular waves in cyclic sheep. This study was funded by OMAFRA and NSERC grants. Appreciation is extended to Norman C. Rawlings, Susan Cook, and Sekallu Srinivas (University of Saskatchewan) and the staff at Ponsonby Sheep Research Station.

Effect of 1 or 2 norgestomet implants inserted from days 15 to 25 after oestrus on follicular development in beef cows

1996 ◽  
Vol 1996 ◽  
pp. 133-133
Author(s):  
D.A. Adikpe ◽  
M.J. Bryant
Keyword(s):  
Pregnancy Rate ◽  
False Positive ◽  
Luteal Phase ◽  
Follicular Development ◽  
Beef Cows ◽  
Beef Heifers ◽  
Follicular Wave ◽  
Ovulatory Follicle

Controlling the timing of ovulation in cows that fail to conceive after insemination would provide a further opportunity for scheduled rebreeding in a group of cows to save time and optimise results. The ear implant Crestar containing the synthetic progestagen norgestomet provides a means of achieving this control (Sinclair et al., 1992; Lowman et al., 1994). Removing the implant on day 25 after oestrus results in less false positive pregnancy diagnoses than removal on day 21 with the implant in place for nine/ten days. However, treatment of beef heifers with a norgestomet implant towards the end of luteal phase to control oestrus and ovulation is associated with development of a persistent ovulatory follicle and reduced pregnancy rate (Mihm et al., 1994). The objective of this study was to determine the effects of treating beef cows with one or two norgestomet implants on the development of the dominant ovulatory follicle of the second follicular wave.

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