Local regulation of oxygen supply in rat skeletal muscle in vivo: variations in hemodynamic response
Bibliographic record
Abstract
To test the hypothesis that red blood cells (RBC) regulate oxygen (O 2 ) supply within organs we used a gas exchange chamber in the stage of an inverted microscope to alter the O 2 environment at a muscle surface (rat extensor digitorum longus) using computer controlled gas flowmeters. With temperature and CO 2 levels constant, the microvascular response to sine oscillations in chamber O 2 levels (3 cycles, period 120 seconds) were determined by measuring hemodynamic parameters: RBC velocity ( v ), capillary hematocrit ( Hc ), RBC supply rate ( SR ) and RBC O 2 saturation levels in capillaries near the muscle surface using our functional microvascular imaging system. Sine oscillations in chamber O 2 caused oscillations in capillary hemodynamics which were 180 degrees out of phase with the chamber O 2 . To determine if there was a significant regulatory response, the r 2 correlation between the measured oscillation in chamber O 2 and in capillary v , SR and Hc were calculated for 13 capillaries (7 rats). There were significant correlations with SR , v and Hc in 11, 10 and 9 capillaries respectively. In six capillaries the regulatory response occurred as a change in both v and Hc , but in another six capillaries only one parameter changed ( v – 3, Hc – 3). The variable response is likely due to the relative magnitude of flow distributions at bifurcations deeper in the muscle caused by regulation of arteriolar blood flow to the surface capillaries.
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 | 0.001 |
| 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 | 0.001 |
| 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".