Impact of hibernation on endogenous carbon monoxide concentrations and heme oxygenase activity in thirteen lined ground squirrels ( <i>Ictidomys tridecemlineatus</i> )
Bibliographic record
Abstract
The thirteen-lined ground squirrel ( Ictidomys tridecemlineatus ) experiences periods of torpor in winter months that are associated with reduced body temperature, metabolism, and a significant decrease in heart rate that leads to blood flow reduction [ischemia (I)] to certain tissues. Between torpor events, brief arousals are shown by increased body temperature, metabolic rate, and reperfusion (R) to tissues. These I/R events cause damage in most mammalian tissues, but low to moderate levels of carbon monoxide (CO) have been shown to alleviate injuries in tissues exposed to frequent I/R events. High concentrations of endogenously produced CO have also been reported in the blood and tissues of deep-diving mammals that routinely experience I/R in their tissues. Heme oxygenase (HO) enzymes break down heme, producing CO as a byproduct. We examined CO concentrations and HO activity in tissues from 15 squirrels experiencing consecutive torpor for 1, 3, 4, or 10 days. Lung CO concentrations after 1 day of torpor (8.2 ± 2.3 pmol/mg) increased after 10 days in torpor (14.9 ± 5.2 pmol/mg). Conversely, HO activity in the lung on day 1 of torpor (10.2 ± 2.6 nmol/hr/g) decreased after 10 days in torpor (3.6 ± 1.2 nmol/hr/g). The spleen, an organ involved in erythrocyte turnover, had the highest average CO content among tissues (29.9 ± 7.0 pmol/mg), though values decreased with increased time in torpor (16.9 ± 8.2 pmol/mg). Similarly, HO activity in the spleen was highest in day 1 of torpor (13.5 ± 4.4 nmol/hr/g) and decreased with increased time spent in torpor (11.6 ± 3.7 nmol/hr/g). These findings are the first to report variations in CO and corresponding HO activity in hibernating mammals, providing insight into the physiological significance of this cytoprotective gas during hibernation. 1. NSF Grant (#1927616) 2. Hozier Undergraduate Research Fellowship 2024-2025 3. UNCW Bio and Marine Bio Travel Grant 4. UNCW CSURF Supplies Grant Summer 2023 and Fall 2024 This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.
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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 | 0.000 |
| 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) | 0.000 | 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".