Role of Extra‐Ovarian Oestrogens in the Regulation of Gonadotropin Releasing Hormone mRNA Expression in the Rat Brain
Bibliographic record
Abstract
To further understand the role of oestrogens in the regulation of gonadotropin releasing hormone (GnRH) mRNA expression in the female rat brain, the effect of EM-652.HCl, a pure anti-oestrogen, was studied in intact and ovariectomized rats as well as in rats chronically treated with a GnRH agonist D-trp6, des-Gly-NH210 GnRH ethylamide (GnRH-A), a treatment which blocks ovarian steroidogenesis. Quantitative in situ hybridization was used to measure GnRH mRNA at the cellular level in the preoptic-anterior hypothalamic area. It was found that, 49 weeks after ovariectomy (OVX), the number of silver grains per cell corresponding to GnRH mRNA was increased by 34%. Long-term administration (49 weeks) of EM-652.HCl to OVX rats resulted in a further increase (11% over the levels measured in OVX rats) in the hybridization signal. By contrast, in intact female rats, treated during 52 weeks with EM-652.HCl, a 49% increase in the GnRH hybridization signal was detected. In rats treated with GnRH-A during the same period, a 20% decrease in GnRH mRNA was observed. When EM-652.HCl was administered concomitantly with GnRH-A, a further 63% increase over the mRNA levels recorded in GnRH-A treated rats was found. Thus, long-term treatment with the anti-oestrogen EM-652.HCl can upregulate GnRH mRNA expression in intact female rats, OVX rats and female rats chronically treated with a GnRH-A. It is suggested that the pure anti-oestrogen EM-652.HCl can exert an influence on the oestrogen feedback mechanism involved in the regulation of GnRH neuronal activity by neutralizing the action of locally produced or low circulating levels of oestrogens remaining after OVX or GnRH-A treatment.
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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 | 0.000 | 0.001 |
| 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".