The vasoconstrictor agent phenylephrine selectively modulates endothelium‐ vs. smooth muscle‐mediated inhibition of myogenic tone in rat cremaster arteries (677.5)
Bibliographic record
Abstract
The α1‐adrenergic agonist phenylephrine (PE) is reported to impact endothelium‐mediated vasorelaxation by influencing vasoactive signals transferred from endothelium to vascular smooth muscle (VSM), however, it is unclear whether this putative process occurs in myogenically active vessels at physiologic pressures. In the present study, we have examined the impact of PE and the TP receptor agonist U46619 on endothelium‐dependent and independent vasorelaxation of cannulated rat cremaster arterioles pressurized to 70 mmHg in the absence of luminal flow. Vasorelaxant agents acting via the endothelium (i.e. 0.3 μM acetylcholine (ACh) and 3 μM SKA‐31) or directly on VSM (i.e. 10 μM adenosine (ADO), 10 μM SNP, 5 μM pinacidil) reversibly inhibited myogenic tone by 50‐80%. Bath addition of 25 nM PE evoked a modest constriction on top of the existing myogenic tone, but did not alter the magnitude of vasorelaxant responses to ACh and SKA‐31. However, ADO‐mediated vasorelaxation was somewhat depressed and the response to pinacidil was enhanced. In the presence of U46619 (5 nM), no clear effects on either endothelium‐dependent or ‐independent vasodilatory stimuli were noted. In summary, the cellular pathways activated by PE and U46619 in VSM do not appear to influence endothelium‐mediated inhibition of myogenic tone in cremaster arterioles, suggesting that myo‐endothelial communication is unaffected by signaling events occurring downstream of α1‐adrenoceptor or TP receptor activation in these vessels. Grant Funding Source : Supported by CIHR
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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) | 0.000 | 0.001 |
| 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".