Level of Sympathetically Mediated Arteriolar Control is Inversely Dependent on Arteriolar Segment Length in Rat Gluteus Maximus Microvascular Networks
Bibliographic record
Abstract
The sympathetic nervous system (SNS) releases neuropeptide Y (NPY, acting on Y1-receptors, Y1R) and norepinephrine (NE, acting on α-adrenoreceptors) that constrict skeletal muscle arterioles to modulate their resistance and blood flow. We recently reported that αR and Y1R control displayed topological dependency; in that α-adrenoreceptor control was greatest at proximal vessels (i.e., 1st and 2nd order arterioles), while NPY mediated effects were greatest on distal vessels, closest to capillaries (i.e., 4th and 5th order arterioles). In spite of this, we noted significant variability in the modulation of sister arterioles of differing segment lengths at bifurcations of the same order. Therefore, in the current study we hypothesized that SNS modulation would be inversely dependent on arteriolar segment length. Intravital video-microscopy was performed on the rat gluteus maximus muscle and arteriolar lengths and constrictor responses to phenylephrine (PE, 10-9M to 10-4M, α1R agonist) and NPY (10-13M to 10-9M) were recorded (n=7 rats/group) and grouped with respect to vessel order (2nd order to 5th order). Plots were curve fitted (exponential decay) and goodness of fit (R2) values were evaluated. We found strong relationships (R2 = 0.8 to 0.99) between arteriolar lengths and the levels of sympathetic constriction for all conditions. These data highlight the need for considering microvascular geometry/topology when interpreting data in studies of microvascular control. NSERC
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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".