The Elevation of Cardiac Hsp70 in Female Rats is Dependent on Estrus Cycle Stage
Bibliographic record
Abstract
Intense exercise elevates the cardioprotective heat-shock protein, HSP70, in the hearts of adult male rats but not females. Estrogen has been linked to this gender difference. However, circulating estrogen levels vary considerably with estrus cycle stage in adult females. PURPOSE: To determine whether Hsp70 would be elevated 24h following a bout of intense exercise in female rats at stages in the estrus cycle when extrogen levels were depressed. METHODS: Female Sprague-Dawley rats, 56 weeks old, were monitored for estrus cycle stage by vaginal smears. Animals were exercised (60 min continuous treadmill running at 30m/min, 2% grade) when they were determined to be in either metaestrus, diestrus, proestrus or estrus stages of their cycle and killed 24 h after the exercise bout. Non-exercised animals, matched for stage of estrus cycle, were used as controls. Blood was collected pre-death to determine hormone levels and hearts were analyzed for Hsp70 by Western blotting. RESULTS: Estrus stage had no effect on basal expression of cardiac Hsp70, however, during metaestrus (lowest circulating levels of estrogen), cardiac Hsp70 was significantly elevated 24 hrs after exercise relative to control hearts (32.11% vs 12.38%, p < 0.05). No difference in cardiac Hsp70 was observed during any of the other stages. CONCLUSIONS: These results show that the estrus cycle of females profoundly affects the heat-shock reponse to exercise. Further, these results demonstrate that the effects of estrogen are acute such that the hormonal milieu immediately prior to or during the exercise bout is critical in determining the nature of this response.
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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) | 0.002 | 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".