Modulation of cardiac sarcoplasmic reticulum gene expression by lack of oxygen and glucose
Bibliographic record
Abstract
Although ischemia reperfusion has been shown to depress gene expression of the sarcoplasmic reticulum (SR) proteins, such as the ryanodine receptor, Ca2+-pump ATPase, phospholamban, and calsequestrin in the heart, the mechanisms of these changes are not understood. Given the occurrence of hypoxia and the lack of glucose during the ischemic phase, we investigated the effects of these factors on the cardiac SR gene expression. Isolated rat hearts perfused in the absence of oxygen and/or glucose for 30 min showed an increase in the expression of SR genes. However, perfusion of hearts for 60 min with normal oxygenated medium after 30 min of lack of both oxygen and glucose depressed the transcript levels for the SR proteins; these changes did not occur when hearts were deprived of either oxygen or glucose. The effect of intracellular Ca2+-overload, which occurs during reperfusion, was studied by using hearts perfused for 5 min with Ca2+-free medium and then reperfused for 30 min. Ca2+-depletion/repletion induced a dramatic decrease in the transcript levels of the SR genes. These results suggest that the lack of both oxygen and glucose during ischemia are necessary for reperfusion-induced depression in SR gene expression, possibly due to the occurrence of intracellular Ca2+-overload.
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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".