The endothelium-modulated but cyclic GMP-independent vasorelaxant effect of H2S
Bibliographic record
Abstract
Hydrogen sulfide (H2S) is an important endogenous gas that possesses vasorelaxant property. The interaction of H2S with different cellular signaling pathways in vascular smooth muscle cells (SMCs), however, had not been systematically studied. In the present study, the mechanisms for the H2S-induced relaxation of phenylephrine-precontracted rat aortic tissues were further investigated. Removal of endothelium from vascular tissues reduced the H2S-induced vasorelaxation by shifting to the right of the concentration-response curve of H2S, but did not affect the maximal relaxation responses. Denervation of vascular tissues did not affect the vasorelaxation induced by H2S. The sodium nitroprusside-induced relaxation of aortic tissues was completely abolished by 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ), a soluble guanylate cyclase inhibitor. Instead of inhibition, ODQ potentiated the H2S-induced vasorelaxation. Inhibitors of cAMP, protein kinase C, and cyclo-oxygenase pathways did not affect the H2S-induced relaxation. In the absence of calcium from the bath solution, the relaxant effect of H2S was significantly attenuated. Prior exposure to H2S reduced the relaxant response of vascular tissues to nitric oxide. Our results suggest that the vasorelaxant effect of H2S was largely due to the interaction of H2S with smooth muscle cells and partially mediated by endothelium in an extracellular calcium entry-dependent manner. The mechanisms for the H2S-induced vasorelaxation were different from those of other gaseous vasoactive factors, such as nitric oxide or carbon monoxide that relax vascular smooth muscles by activating cGMP-dependent pathway. The interaction among these endogenous gases may provide fine tune of vascular tone. Supported by HSURC of Saskatchewan, Canada.
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) | 0.001 | 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".