Arachidonic acid activates phospholipase D in human neutrophils; essential role of endogenous leukotriene B4 and inhibition by adenosine A2A receptor engagement
Bibliographic record
Abstract
We report in human neutrophils (PMN) that phospholipase D (PLD) was stimulated by micromolar concentrations of arachidonic acid (AA) and nanomolar concentrations of leukotriene B(4) (LTB(4)), and eicosapentaenoic acid was inactive. The stimulatory effect of AA occurred only when adenosine was eliminated from PMN suspensions or when PMN were incubated with adenosine A(2A) receptor antagonists. The mechanism of AA-induced PLD activation was investigated. The results show that AA- and LTB(4)-induced PLD activation were inhibited by the LTB(4) receptor 1 (BLTR1) antagonist CP 105,696, whereas the LTA(4) hydrolase inhibitor SC57461A and the LT biosynthesis inhibitor MK-0591 inhibited AA- but not LTB(4)-mediated PLD activation. The AA-induced ARF1 and RhoA translocation to PMN membranes was inhibited by CP 105,696 and SC57461A. These results provide evidence of a requirement for an autocrine-stimulatory loop involving LTB(4) and BLTR1 in the translocation of small GTPases to membranes and the activation of PMN PLD by AA.
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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 | 0.001 |
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".