Cellular calcium regulatory machinery of vasorelaxation elicited by petasin
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
1. The present study examined the cytosolic Ca(2+) regulatory machinery involved in the vasorelaxation produced by petasin, a sesquiterpene isolated from Petasites formosanus. 2. Aortic rings isolated from Sprague-Dawley rats were exposed to petasin (0.01-100 micromol/L) to elucidate its vascular effects on isometric contraction elicited by vasoconstrictors, as well as the contribution of the endothelium and Ca(2+) to the responses observed. In addition, L-type voltage-dependent Ca(2+) channel (VDCC) activity and [Ca(2+)](i) were determined in cultured vascular smooth muscle cells (VSMCs) from Sprague-Dawley rats in the presence of 1-100 micromol/L petasin using whole-cell patch-clamp recording and the fluorescent probe fura-2/AM. The effects of petasin on vascular responses were compared between aortic rings from spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. 3. Petasin reduced isometric contraction elicited by KCl or the L-type Ca(2+) channel opener BayK 8644 (IC(50) 3.0 +/- 0.4 and 4.1 +/- 1.1 micromol/L, respectively) in aortic rings isolated from Sprague-Dawley rats, independent of the endothelium. In addition, petasin triggered a rightward shift in the concentration-response curve to KCl while reducing the maximal response by 82%. In Ca(2+)-depleted and high K(+)-depolarized aortic rings, 1-100 micromol/L petasin pretreatment attenuated the Ca(2+)-induced contraction in a concentration-dependent manner. 4. In cultured VSMCs, whole-cell patch-clamp recording revealed that petasin inhibited VDCC activity. Measurement of [Ca(2+)](i) using fura-2/AM fluorescence indicated that petasin suppressed the KCl-induced increase in [Ca(2+)](i). However, receptor binding assays failed to identify any significant interaction between petasin and the dihydropyridine binding sites of the L-type VDCC. 5. In aortic rings from SHR and WKY rats, petasin inhibited Ca(2+)-induced contractions in Ca(2+)-depleted and high K(+)-depolarized solution with a more pronounced effect in rings from SHR. 6. Together, the results suggest that direct Ca(2+) antagonism of L-type VDCC in vascular smooth muscle may account, at least in part, for petasin-induced vasorelaxation. The more pronounced effect of the sesquiterpene in blood vessels from SHR suggests its possible therapeutic potential in the mangement of hypertension.
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.
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) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| 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 it