Acute superoxide scavenging reduces sympathetic vasoconstrictor responsiveness in short-term exercise-trained rats
Bibliographic record
Abstract
We hypothesized that acute superoxide (O2(-)) scavenging would attenuate sympathetic vasoconstrictor responsiveness by augmenting nitric oxide (NO)-mediated inhibition of sympathetic vasoconstriction in exercise-trained rats. Sprague-Dawley rats were randomly assigned to sedentary time control (S; n = 7) or mild- (M: 20 m/min, 5° grade; n = 7) or heavy-intensity (H: 40 m/min, 5° grade; n = 7) exercise training (ET) groups and trained 5 days/wk for 4 wk with matched training volume. Following ET, rats were anesthetized and instrumented for lumbar sympathetic chain stimulation and measurement of femoral vascular conductance. In resting skeletal muscle, the percentage change of femoral vascular conductance in response to continuous (2 Hz) and patterned (20 and 40 Hz) sympathetic stimulation was determined during control conditions, O2(-) scavenging (TIRON, 1 g·kg(-1)·h(-1) iv) and combined O2(-) scavenging + nitric oxide synthase blockade (N(ω)-nitro-l-arginine methyl ester, 5 mg/kg iv). ET augmented the vasoconstrictor response to sympathetic stimulation in a training intensity-dependent manner (P < 0.05) (S: 2 Hz: -26 ± 7.1%; 20 Hz: -26.9 ± 7.3%; 40 Hz: -27.7 ± 7.0%; M: 2 Hz: -37.4 ± 8.3%; 20 Hz: -35.9 ± 7.4%; 40 Hz: -38.2 ± 9.4%; H: 2 Hz: -46.9 ± 7.8%; 20 Hz: -48.5 ± 7.2%; 40 Hz: -51.2 ± 7.3%). O2(-) scavenging did not alter (P > 0.05) the vasoconstrictor response in S rats (S: 2 Hz: -23.9 ± 7.6%; 20 Hz: -26.1 ± 9.1%; 40 Hz: -27.5 ± 7.2%), whereas the response in ET rats was diminished (M: 2 Hz: -26.3 ± 5.1%; 20 Hz: -28.7 ± 5.3%; 40 Hz: -28.5 ± 5.6%; H: 2 Hz: -35.5 ± 10.3%; 20 Hz: -38.6 ± 6.8%; 40 Hz: -43.9 ± 5.9%, P < 0.05). TIRON + N(ω)-nitro-l-arginine methyl ester increased vasoconstrictor responsiveness (P < 0.05) in ET rats (M: 2 Hz: -47.7 ± 9.8%; 20 Hz: -41.2 ± 7.2%; 40 Hz: -50.5 ± 7.9%; H: 2 Hz: -55.8 ± 7.6%; 20 Hz: -55.7 ± 7.8%; 40 Hz: -58.7 ± 6.2%), whereas, in S rats, the response was unchanged (2 Hz: -29.4 ± 8.7%; 20 Hz: -30.0 ± 7.4%; 40 Hz: -35.2 ± 10.3%; P > 0.05). These data indicate that the augmented sympathetic vasoconstrictor responsiveness in ET rats was related to increased oxidative stress and altered nitric oxide-mediated inhibition of vasoconstriction.
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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) | 0.001 | 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".