Progesterone as the driving regulatory force behind serum FSH concentrations and antral follicular development in cycling ewes
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Ovarian antral follicles in sheep grow in an orderly succession, producing typically three to four follicular waves per 17-day oestrous 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 oestrous cycle, the time between the first two FSH peaks and days of wave emergence is longer than the intervals separating the ensuing FSH peaks and follicular waves. The prolonged interpeak and interwave interval occurs early in the luteal phase when low levels of progesterone are secreted by developing, or not fully functional, corpora lutea (CL). The purpose of the present study was to determine the effect of varying progesterone (P(4)) levels on circulating concentrations of FSH and antral follicular development in sheep. Exogenous P(4) (15 mg per ewe, i.m.) was administered twice daily to six cycling Rideau Arcott×Dorset ewes from Day 0 (ovulation) to Day 4 (the mean duration of the interwave interval); six animals served as controls. Follicular growth was monitored in all animals by daily transrectal ultrasonography (Days 0-9). Jugular blood samples were drawn twice a day from Day 0 to Day 4 and then daily until Day 9 to measure systemic concentrations of P(4), FSH and 17β-oestradiol (E(2)). The first FSH peak after ovulation was detected on Days 1.5±0.2 and 4.2±0.2 in treated and control ewes, respectively (P<0.05). The next FSH peak(s) occurred on Day 3.9±0.3 in the treated group and on Day 6.4±0.5 in the control group. Consequently, the treated group had, on average, three follicular waves emerging on Days 0, 3 and 6, whereas the control group had two waves emerging on Days 0 and 5. Mean serum E(2) concentrations were greater (P<0.05) in control compared with treated ewes on Days 1.3, 2.3, 3.3, 4.0 and 4.3 after ovulation. In summary, creation of mid-luteal phase levels of P(4) in metoestrus shortened the time to the first post-ovulatory FSH peak in ewes, resulting in the emergence of one more follicular wave compared with control ewes during the same time frame. Therefore, P(4) appears to be a key endocrine signal governing the control of periodic increases in serum FSH concentrations and the number of follicular waves in cycling sheep.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it