Restricted ability of human mast cell tryptase to activate proteinase-activated receptor-2 in rat aorta
Bibliographic record
Abstract
We investigated the potential of human mast cell tryptase to induce relaxation of rat aorta. Trypsin and the selective PAR2-activating peptide (PAR2-AP) SLIGRL-NH2 stimulated robust relaxation of phenylephrine-precontracted rat aortic rings. However, human lung tryptase (1-100 nM) either in the presence or absence of heparin failed to induce any significant relaxation. Notwithstanding, incubation of the aorta with tryptase (100 nM), following the addition of a peptide corresponding to the cleavage/activation sequence of rat PAR2 (rPAR2), resulted in relaxation of precontracted tissue due to the proteolytic release of the PAR2-AP SLIGRL/ from the parent peptide. Thus, tryptase was enzymatically active in the bioassay system. Preincubation of aorta with neuraminidase to remove cell-surface sialic acid unmasked the ability of tryptase to induce relaxation of the aorta, but had no effect on relaxation induced by trypsin, SLIGRL-NH2, or acetylcholine (Ach). Like trypsin and SLIGRL-NH2, the tryptase-induced relaxation was inhibited by either removal of the endothelium or pretreatment of the tissue with NG-nitro-L-arginine methyl ester (L-NAME), suggesting an endothelium-derived nitric oxide mechanism. Interestingly, tryptase in the presence of heparin failed to induce relaxation of precontracted neuraminidase-treated rat aorta. We conclude that tryptase-induced relaxation of rat aorta, most likely via PAR2, is tightly regulated by heparin and cell-surface sialic acid.
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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 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) | 0.014 | 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".