Non ‐ adrenergic receptor mediated tonic vasoconstriction in skeletal muscle does not change with age
Bibliographic record
Abstract
Sympathetic co‐transmitter release may increase with aging. Thus, non‐adrenergic receptor mediated vasoconstriction may assume a greater role in the control of skeletal muscle vascular tone with aging. The purpose of this study was to investigate the effect of age on neuropeptide Y ‐ Y 1 (NPY) and purinergic (P2X) receptor mediated restraint of skeletal muscle blood flow. Young (n = 6; 22 ± 3 months) and old (n = 7; 119 ± 22 months) beagles were studied. Selective NPY (BIBP‐3226; 2.5 mg bolus) and P2X receptor (PPADS; 40 mg bolus) antagonists were infused at rest, and during treadmill running at 2.5 miles/h and 4 miles/h with 2.5% grade. Hindlimb blood flow (HBF) and mean arterial pressure (MAP) were monitored continuously and vascular conductance (VC) was calculated. Infusion of BIBP‐3226 resulted in similar increases in VC in young and old beagles at rest (Young 137 ± 64 % ; Old:, 96 ± 54 % ) and at 2.5 miles/h (Young 56 ± 39 % ; Old:, 52 ± 24 %) and 4 miles/h with 2.5% grade (Young: 45 ± 24 %; Old: 39 ± 35 %). PPADS infusion also produced similar increases in VC in young and old beagles at rest (Young: 88 ± 35 %; Old: 164 ± 143 %) and at 2.5 miles/h (Young: 47 ± 43 %; Old: 31 ± 27 %) and 4 miles/h with 2.5% grade (Young: 26 ± 33 %; Old: ‐13 ± 21 %). These results demonstrate that NPY and P2X receptor mediated restraint of skeletal muscle blood flow does not increase in older compared to young beagles at rest or during dynamic exercise.
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) | 0.000 | 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) | 0.002 | 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".