QX-314 Produces Long-lasting Local Anesthesia Modulated by Transient Receptor Potential Vanilloid Receptors in Mice
Bibliographic record
Abstract
BACKGROUND: The quaternary lidocaine derivative QX-314 is now known to produce long-lasting local anesthesia despite its positive charge. However, recent research suggests that the transient receptor potential vanilloid receptor agonist, capsaicin, should reduce the onset and offset times, whereas the transient receptor potential vanilloid receptor antagonist, capsazepine, should delay the onset time of sensory blockade by QX-314. METHODS: Sensory blockade in the tail of the conscious mouse was investigated using QX-314 2.5% in combination with capsaicin 0.1% and/or capsazepine (50 microg/ml). After tail injection, onset and offset times of local anesthesia were measured using the hot water tail-flick latency test. RESULTS: Capsaicin reduced the onset time of local anesthesia by QX-314 by more than 75% (Mann-Whitney test, P = 0.007; n = 10 per group) with no effect on the offset time of QX-314. For QX-314 without capsaicin, the onset and offset times were 23 min (interquartile range 15-30 min) and 300 min (interquartile range 285-375 min), respectively. For QX-314 with capsaicin, the onset and offset times were 4 min (interquartile range 3-8 min) and 360 min (interquartile range 285-435 min), respectively. In the antagonist study, capsazepine without added capsaicin decreased QX-314's efficacy, as 6 out of 9 mice did not develop sensory blockade after 90 min (Fisher exact test, P = 0.009). CONCLUSION: We have confirmed in a sensory blockade model that QX-314 is a local anesthetic with a slow onset and a long duration of reversible blockade. Capsaicin, a transient receptor potential vanilloid receptor agonist, accelerated QX-314's onset kinetics, whereas capsazepine, a transient receptor potential vanilloid receptor antagonist, decreased QX-314's efficacy. These observations raise the possibility that endovanilloids may modulate cell entry of QX-314.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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".