Protective roles of estradiol against vascular oxidative stress in ovariectomized female rats exposed to normoxia or intermittent hypoxia
Bibliographic record
Abstract
Abstract Aim We tested the hypothesis that estradiol (E2) reduces aortic oxidative stress and endothelial dysfunction in ovariectomized (OVX) female rats exposed to room air (RA) or chronic intermittent hypoxia (CIH). Methods We used intact or OVX female rats treated with vehicle or E2 (0.5 mg/kg/d) and exposed to RA or CIH (21%‐10% O2, 10 cycles/h, 8 h/d) for 7 or 35 days, and measured the arterial pressure, heart rate and plasma endothelin‐1 levels. We also measured in thoracic aortic samples, the activities of the pro‐oxidant enzymes NADPH (NOX) and xanthine oxidase (XO), the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase and the advanced oxidation protein products (AOPP—oxidative stress marker). Finally, we used aortic rings to assess the contractile response to phenylephrine and the vasodilatory response to acetylcholine. Results After 7 or 35 days of CIH, E2 supplementation reduced arterial pressure. E2 reduced plasma endothelin‐1 levels after 7 days of CIH, but not after 35 days. Ovariectomy, but not CIH for 7 days, increased aortic oxidative stress and E2 treatment prevented this effect. Remarkably, in animals exposed to RA, this was achieved by a reduction in NOX and XO activities, but in animals exposed to CIH this was achieved by increased catalase activity. In OVX female rats exposed to CIH for 7 days, E2 supplementation improved the NO‐mediated vasodilation. After 35 days of CIH, enzymatic activities, AOPP and aortic reactivity were similar in all groups. Conclusion E2‐based therapy could help prevent the vascular consequences of CIH in apneic women.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 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 | 0.000 | 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".