Differential Role of Cation and Anion Exchange in Lymphocyte pH Regulation
Bibliographic record
Abstract
In lymphocytes, the Na+/H+ antiport is well suited to function in cytoplasmic pH (pHi) regulation. It is activated by departures from the physiological pHi and is thermodynamically poised to compensate for the tendency of the cells to become acidic. The driving force for H+ (equivalent) efflux is indirectly provided by the Na+ pump. Lymphocytes also possess a cation-independent anion (Cl-/HCO3-) exchange system, which, under the appropriate conditions, tends to restore pHi after an alkali load. Unlike the cation antiport, the source of energy driving the anion exchanger, i.e. the factors that determine the transmembrane Cl- distribution, is not well understood. The contribution of conductive pathways appears to be minimal, resulting in a marked difference between the membrane potential and ECl-. Instead, ECl- is very similar to EH+. Moreover, changes in the distribution of Cl- lead to alterations in the transmembrane delta pH and vice versa, suggesting a relationship between these parameters. Evidence is presented which suggests that the transmembrane distribution of HCO3-, dictated by delta pH, is a major determinant of the intracellular Cl- concentration, a process mediated by the anion exchanger. Thus, if Cl- is driven by the gradient of HCO3-, the cation-independent anion exchanger cannot play an active role in determining pHi. Instead, Cl-/HCO3- exchange may simply stabilize pHi by increasing the dynamic buffering power of the cells. Cation-independent Cl-/HCO3- exchange could be involved in pHi regulation only if coupled to a separate mechanism of intracellular Cl- accumulation, such as Na+-K+-2Cl- co-transport or an inward Cl- pump, which have not been detected in lymphoid cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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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) | 0.000 | 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".