Pharmacological and Developmental Evidence that the Potassium-Induced Stimulation of Deoxyglucose Uptake in Astrocytes Is a Metabolic Manifestation of Increased Na <sup>+</sup> -K <sup>+</sup> -ATPase Activity
Bibliographic record
Abstract
There is disagreement in the literature whether or not deoxyglucose accumulation, a measure of glycolytic activity, is increased in astrocytes during exposure to elevated concentrations of the potassium ion (K+). In the present work we have confirmed our previous finding that deoxyglucose accumulation in primary cultures of well-differentiated mouse astrocytes shows a robust increase when the K+ concentration in the incubation medium is raised to or above 12 mM. This response is inhibited by ouabain (with a half-maximum effect at approximately 0.1 mM), indicating that it is a metabolic manifestation of the activity of an Na(+)-K(+)-ATPase. The stimulation at this high level of K+ indicates a remarkably low K+ affinity of the Na(+)-K(+)-ATPase involved, enabling it to be activated by above-normal concentrations of K+. At a resting concentration of K+ (5.4 mM), at least one half of the deoxyglucose accumulation is also a reflection of Na(+)-K(+)-ATPase activity, as shown by its susceptibility to inhibition by ouabain. Ouabain has some effect even at a concentration of 0.1 microM, indicating participation of not only the alpha 1 isoform which has a low affinity to ouabain, but also of the alpha 2 isoform, which has a high affinity. The stimulatory effect of elevated K+ is absent in immature astrocytes and only develops after prolonged time in culture. It could not be evoked in a seemingly similar culture of rat astrocytes, which has previously been shown to lack Na(+)-K(+)-ATPase activity as well as the alpha 2 isoform of the ATPase. This isoform has unequivocally been found to be expressed by astrocytes in situ.
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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 | 0.001 |
| 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".