K<sub>ATP</sub> channel deficiency in mouse flexor digitorum brevis causes fibre damage and impairs Ca<sup>2+</sup> release and force development during fatigue <i>in vitro</i>
Bibliographic record
Abstract
Activation of the K(ATP) channels results in faster fatigue rates as the channels depress action potential amplitude, whereas abolishing the channel activity has no effect in whole extensor digitorum longus (EDL) and soleus muscles. In this study, we examined the effects of abolished K(ATP) channel activity during fatigue at 37 degrees C on free intracellular Ca(2+) (Ca(2+)(i)) and tetanic force using single muscle fibres and small muscle bundles from the flexor digitorum brevis (FDB). K(ATP) channel deficient muscle fibres were obtained (i) pharmacologically by exposing wild-type fibres to glibenclamide, and (ii) genetically using null mice for the Kir6.2 gene (Kir6.2(-/-) mice). Fatigue was elicited using 200 ms tetanic contractions every second for 3 min. This study demonstrated for the first time that abolishing K(ATP) channel activity at 37 degrees C resulted in faster fatigue rates, where decreases in peak Ca(2+)(i) and tetanic force were faster in K(ATP) channel deficient fibres than in control wild-type fibres. Furthermore, several contractile dysfunctions were also observed in K(ATP) channel deficient muscle fibre. They included partially or completely supercontracted single muscle fibres, greater increases in unstimulated Ca(2+)(i) and unstimulated force, and lower force recovery. We propose that the observed faster rate of fatigue in K(ATP) channel deficient fibres is because the decreases in peak Ca(2+)(i) and force caused by contractile dysfunctions prevail over the expected slower decreases when the channels do not depress action potential amplitude.
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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 | 0.001 | 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) | 0.000 | 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".