Effect of Nitric Oxide Synthase Inhibitor Nω Nitro-l-Arginine Methyl Ester on Relaxant Responses to Calcium Channel Antagonists in Isolated Aortic Rings from Dahl Normotensive and Hypertensive Rats
Bibliographic record
Abstract
Differences exist between the pharmacological actions of calcium channel antagonists in blood vessels from hypertensive versus normotensive animals. In this investigation, we have examined the impact of nitric oxide synthase inhibitor N(omega) nitro-L-arginine methyl ester (L-NAME) on relaxant responses produced by the calcium channel antagonists (nifedipine, diltiazem, and mibefradil) in isolated aortic rings from Dahl salt-resistant normotensive (SRN) and salt-sensitive hypertensive (SSH) rats on a 4% salt diet. Morphological examination of the aortic rings revealed significantly larger lumen area, smooth muscle wall thickness, and perimeter in vessels of SSH rats versus SRN rats. Rank order potency for the antagonists was nifedipine > mibefradil > or = diltiazem in aortic rings from SRN rats, but mibefradil was found to be the most efficacious. The rank order potency for the antagonists in aortic rings from SSH rats was nifedipine > diltiazem > mibefradil, although all three drugs showed similar efficacy. The presence of L-NAME attenuated relaxations elicited by the antagonists in aortic rings from SRN rats. Treatment of tissues with L-NAME significantly reduced maximal response and decreased pIC(50). The presence of L-NAME had no effects on concentration-response curves to nifedipine and diltiazem in aortic rings from SSH rats, but it significantly attenuated relaxant responses of mibefradil. Our current results support the view that these calcium channel antagonists produce relaxations by mechanisms that are sensitive and insensitive to L-NAME. Moreover, the component insensitive to L-NAME was lacking in tissues from SSH rats for nifedipine and diltiazem but not mibefradil.
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 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 | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| 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) | 0.000 | 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".