The effects of drugs modulating K<sup>+</sup> transport on Rb<sup>+</sup> uptake and distribution in pig hearts following regional ischemia: <sup>87</sup>Rb MRI study
Bibliographic record
Abstract
The effects of drugs that can modulate passive permeability of K(+) into cardiomyocytes in normal and reperfusion-damaged cardiac muscle were assessed. Rubidium ion (Rb(+)) was used as a K(+) tracer and (87)Rb-MRI as a detection method. The left anterior descending artery (LAD) of isolated pig hearts perfused with Krebs-Henseleit buffer (KHB) was occluded for 2 h and subsequently reperfused for 2 h with KHB containing 4.7 mM RbCl instead of KCl. The buffer contained either a blocker of ATP-sensitive K(+) channels (K(ATP)), glibenclamide (Glib, 3 micro M), a K(ATP) opener, pinacidil (Pin, 10 micro M), a K(+)/Na(+)/2Cl(-) co-transporter inhibitor, bumetanide (Bum, 10 micro M) or no drug (control). Upon reperfusion three-dimensional (87)Rb MR images were acquired to obtain kinetics of Rb(+) uptake and its distribution. Areas at risk (AAR) and areas of necrosis were determined by Evans Blue and triphenyl tetrazolium chloride staining, respectively. Rb(+) uptake kinetics in the remote posterior (Pos) wall were similar in all groups. The kinetics remained monoexponential in the affected anterior (Ant) wall and the uptake rates were 32, 36, 37 and 21% of that in the Pos wall in the control, Glib, Pin and Bum groups, respectively. Infarct sizes determined histologically as a percentage of total ventricular (left + right) mass (14-22%) corresponded to sizes of areas with 20-40% of maximal Rb image intensity [I(Rb)(max), 15-22%], except for the Pin group (12.5 vs 21%). The sizes of areas with 20-50% of I(Rb)(max) (30-36%) closely correlated with those of AAR determined histologically (31-33%). Lactate dehydrogenase release did not differ in all groups. We conclude that: (1) reperfusion damage quickly inhibits Rb(+) uptake; (2) Rb(+) uptake in normal and reperfused tissue does not significantly depend on K(ATP) or the K(+)/Na(+)/2Cl(-) cotransporter; (3) areas with 20-40% of maximal image intensity correspond to infarct areas.
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 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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| 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) | 0.000 | 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".