Electrophysiological effects of the natriuretic peptides BNP and CNP in the sinoatrial node and atrial myocardium
Bibliographic record
Abstract
Natriuretic peptides (NPs), including ANP, BNP and CNP, constitute a family of hormones that elicit their effects by binding to three receptors denoted NPR-A, NPR-B and NPR-C. The electrophysiological effects of NPs in the heart, particularly in the specialized pacemaker cells of the sinoatrial node (SAN), are poorly understood; therefore, we have investigated the effects of BNP and CNP (10 and 100 nM) on isolated SAN and working atrial myocytes. BNP and CNP increased spontaneous action potential (AP) frequency and increased the slope of the diastolic depolarization in SAN myocytes. Voltage-clamp experiments demonstrate that these effects are the result of increases in the pacemaker current (If) and L-type Ca2+ current (ICa,L). In contrast to SAN myocytes, BNP had no effect on AP parameters in working atrial myocytes under basal conditions. Stimulation of atrial myocytes with isoproterenol (ISO; 10 nM) increased AP duration as well as ICa,L. Application of BNP following prestimulation with ISO further increased atrial myocyte AP duration and ICa,L. The effects of BNP and CNP on SAN myocytes are maintained in mutant mice lacking functional NPR-C receptors. These data suggest that BNP and CNP increase SAN myocyte firing frequency by activating the guanylyl cyclase-linked NPR-A and NPR-B receptors and that the sensitivity of the SAN to NPs is greater than the surrounding working myocardium.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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".