Cortisol/Progesterone Antagonism in Regulation of 15-Hydroxysteroid Dehydrogenase Activity and mRNA Levels in Human Chorion and Placental Trophoblast Cells at Term
Bibliographic record
Abstract
PGs mediate parturition events. 15-Hydroxyprostaglandin dehydrogenase (PGDH) catalyzes the first step in the metabolism of PGs to render them inactive. We have reported previously that cortisol (F) decreases PGDH activity and progesterone (P(4)) maintains PGDH in human chorion and placenta at term. To study the interaction of P(4) and F on the regulation of PGDH, we treated chorion and placental trophoblast cells in culture with combinations of F, dexamethasone, P(4), trilostane, and medroxyprogesterone acetate (MPA). Following a 24-h steroid treatment period and 4-h PGF(2alpha) challenge, culture media and cells were collected for measurement of PGF(2alpha) levels and PGDH mRNA by RIA and Northern blotting analysis. F and dexamethasone decreased PGDH activity and mRNA levels. Exogenous P(4) did not significantly alter PGDH activity or mRNA levels; however, MPA significantly stimulated PGDH activity. Trilostane decreased P(4) production by more than 90% and also decreased PGDH activity and expression. Coincubation with P(4) or MPA reversed trilostane inhibition of PGDH, consistent with a stimulatory role for endogenous P(4) on PGDH. MPA significantly reversed F inhibition of PGDH activity and mRNA levels. In the presence of trilostane, P(4) at equimolar concentration to F reversed F inhibition of PGDH mRNA levels. These findings suggest that F may be acting as an endogenous inhibitor of P(4) action in the regulation of PGDH at term.
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How this classification was reachedexpand
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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".