Lack of both oxygen and glucose contributes to I/R-induced changes in cardiac SR function
Bibliographic record
Abstract
Although ischemia-reperfusion (I/R) has been shown to depress cardiac performance and sarcoplasmic reticulum (SR) function, the mechanisms underlying these alterations are poorly understood. Because lack of oxygen and substrate deprivation are known to occur during the ischemic phase, we examined the effects of reperfusion on cardiac performance and SR function in hearts subjected to hypoxia and substrate lack. For this purpose, isolated rat hearts were perfused with hypoxic and/or glucose-free medium for 30 min and then reperfused with normal medium for 1 h; the SR vesicles were isolated for studying the Ca(2+)-transport activities. Reperfusion with normal medium of hearts deprived of oxygen or glucose showed no changes in cardiac performance and SR function. However, reperfusion of hearts perfused with hypoxic glucose-free medium showed ~45% decrease in cardiac contractile activities as well as 23 and 64% reduction in SR Ca(2+)-uptake and Ca(2+)-release activities, respectively, without any change in the level of SR Ca(2+)-cycling proteins. Depressed SR function in these hearts was associated with a reduction in Ca(2+)/calmodulin-dependent protein kinase (CaMK) phosphorylation of the SR Ca(2+)-cycling proteins and 34% decrease in SR CaMK activity. These changes in cardiac performance, SR function, and SR CaMK activity in the hypoxic, glucose-deprived, reperfused hearts were similar to those observed in hearts subjected to 30 min of global ischemia and 60 min of reperfusion. The results therefore suggest that the lack of both oxygen and substrate during the ischemic phase may contribute to the I/R-induced alterations in cardiac performance and SR function. Furthermore, these abnormalities were associated with reduced SR CaMK activity.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.001 | 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) | 0.001 | 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".