The Influence of Calcium Channel Antagonists on Isolated Human Distal Radial Arteries
Bibliographic record
Abstract
A comparison was made between the efficacies and potencies of calcium channel antagonists on contractions induced by 5-hydroxytryptamine, norepinephrine, or high-potassium buffer in isolated human distal radial arteries. Also, the impact of removal of extracellular calcium ions on contractions induced by 5-hydroxytryptamine or norepinephrine was assessed. Isometric contractions were induced by agonists, and relaxant responses to calcium channel antagonists, nifedipine, diltiazem, verapamil, or mibefradil were examined. 5-hydroxytryptamine-induced contractions when compared with norepinephrine or high-potassium induced contractions were significantly more sensitive to inhibition by nifedipine (pIC50 = 7.53 +/- 0.15; 6.78 +/- 0.12; 6.6 +/- 0.22, respectively, mean +/- SEM). Diltiazem was more effective in producing relaxations when contractions were elicited with 5-hydroxytryptamine (pIC50 = 6.48 +/- 0.84) or norepinephrine (pIC50 = 6.20 +/- 0.21) than with high potassium (pIC50 = 5.43 +/- 0.10). Verapamil was more effective at relaxing arteries contracted with 5-hydroxytryptamine (pIC50 = 6.09 +/- 0.19) or norepinephrine (pIC50 = 6.00 +/- 0.17) than with high potassium (pIC50 = 5.60 +/- 0.16). Mibefradil was not very effective in producing relaxations. The studies revealed that removal of extracellular calcium significantly attenuated contractions produced by 5-hydroxytryptamine (-67.7 +/- 6.3%) and norepinephrine (-89 +/- 1.5%). In conclusion, our data indicates that nifedipine was the most effective drug in producing relaxations; also, contractions produced by 5-hydroxytryptamine and norepinephrine were found to be critically dependent on the presence of extracellular calcium.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".