Cardiovascular effects of human ?new pressor protein? (NPP) and coagulation $beta;-FXIIa: its potentiation by the ace inhibitor captopril and by 24hr nephrectomy
Bibliographic record
Abstract
Enzymic ‘New Pressor Protein’ (NPP), related to coagulation β-FXIIa (β-FXIIa), exerts potent cardiovascular effects when injected into bioassay rats, raising systolic/diastolic blood pressure (SBP/DBP), heart rate (HR), stroke volume and cardiac output and triggers massive release of plasma catecholamines (J Hypertens 16:311-20, 1998; Can J Cardiol 18(10):1077-86; 1093-103, 2002). All these effects are potentiated by the ACE inhibitor Captopril (CAP). To further elucidate NPP's mechanism of action and its potentiation by CAP, we investigated whether the removal of renal ACE by 24hr bilateral nephrectomy (2NX) mimics some of the potentiation produced by CAP. Male Wistar rats (∼300g, n=8) were anesthetized with Inactin (100 mg/kg i.p.) and given Pentolinium (19.2 mg/kg s.c.). They were prepared for bioassay after 24hr 2NX or SHAM-2NX (control). NPP (20 μL plasma equivalent i.v.) or β-FXIIa (300 ng/kg i.v.) was injected into −/+CAP (2.5 mg/kg i.v.) treated rats and SBP/DBP/HR was recorded using a MacLab/8 PowerMac 7200 computerized system. In SHAM-2NX control rats, NPP and β-FXIIa produced comparable effects on SBP/DBP/HR and potentiation by CAP was quite similar. However, 2NX alone (-CAP group) produced virtually the same potentiation as +CAP did in SHAM-2NX rats, suggesting that the effect of CAP was primarily expressed via renal ACE. Since tissue ACE is not restricted to the kidney, such a major effect of 2NX suggests that much of the effect of CAP would have to involve renalpeptidase(s) other than ACE. The fact that CAP potentiated HR more than BP increments in 2NX rats suggests that the mechanisms governing HR are not entirely similar to those governing BP. Overall, our results solidify the relationship between NPP and β-FXIIa and demonstrate that their complex mechanism of action on BP and HR are importantly mediated by the kidneys. (See Table) Δ: peak increments over corresponding control baseline. p<0.05 vs. corresponding −CAP group. p<0.05 vs. corresponding SHAM-2NX group. Means ± SEM. Supported by Heart and Stroke Foundation of Ontario grants NA3478 and T4136.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".