Calcium regulates Na <sup>+</sup> :K <sup>+</sup> :2Cl <sup>−</sup> cotransporter function in Malpighian tubules of Rhodnius prolixus
Bibliographic record
Abstract
Rhodnius prolixus is a haematophagous insect, vector of Chagas’ disease. During each blood meal the insect ingests large volumes of blood that may be up to 10 times its unfed weight. The excess of water and ion ingested is expelled thanks to a rapid post‐prandial diuresis triggered by the diuretic hormone serotonin, that stimulate the Malpighian (renal) tubules (MT). Until now, serotonin was believed to stimulate MTs via the second messenger cAMP and Ca 2+ was considered to play no significant role. Here we tested the role of Ca 2+ on serotonin‐stimulated MTs. Our results show that serotonin stimulation triggered Ca 2+ waves in MTs. In addition, incubating tubules in Ca 2+ ‐free saline containing BAPTA‐AM (3 μM) reduced fluid transport by 50%, decreased Na + flux by 70% and decreased pH of the secreted fluid from 7.10±0.05 to 6.20±0.21. Measurements of transepithelial potential suggest a reduced activity of the basolateral Na + :K + :2Cl − cotransporter (NKCC) when chelating Ca 2+ . The results indicate that Ca 2+ is important for normal functioning of the tubules. We hypothesize that Ca 2+ may be involved in NKCC regulation. Disruption of Ca 2+ signalling may alter NKCC activity by changing its phosphorylation state or its insertion to the membrane. Funded by a Natural Sciences and Engineering Research Council of Canada grant to JPI.
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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 | 0.000 |
| 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".