Effect of Physical Training on the Activity of the Low Km Phosphodiesterase in Heart Ventricular and Skeletal Muscle Tissues of Normal and Diabetic Rats
Bibliographic record
Abstract
This study assessed the effect of physical training on the low Michaelis constant cyclic AMP phosphodiesterase (low Km PDE) activity in heart ventricular tissue and three different skeletal muscle tissues of normal and diabetic rats. Rats were rendered diabetic with streptozotocin (45 mg/kg i.v.) and either kept sedentary (SD, n=16) or submitted to a progressive 10-week treadmill running program (TD, n=17). Two groups of nondiabetic rats served as trained (TC, n=17) and sedentary controls (SC, n=15). The activity of NAD-linked isocitrate dehydrogenase was significantly increased (p < 0.001) in the gastrocnemius muscle of trained animals, confirming that they were adequately trained. Plasma glucose levels were elevated in SD rats (18.8 ± 1.7 mmol/l) compared to those in SC rats (7.7 ± 0.2 mmol/l ; mean ± standard error of the mean [SEM], p < 0.001). These levels were partially normalized following training (12.7 ± 1.7 pmol/l; p < 0.01 vs. SD rats). Plasma insulin levels were significantly reduced in TC rats (223 ± 16 pmol/l) compared with those in SC rats (306 ± 13 pmol/l; p < 0.01). Similarly, the levels in SC rats were significantly different when compared with SD rats (155 ± 15 pmol/l; p < 0.01). In TD rats, plasma insulin levels (156 ± 14 pmol/l) were similar to those of SD rats. This suggests that mild diabetes mellitus in the rat can be improved by endurance training and that improved glycemic control may be mediated by an increase in insulin sensitivity. The low Km PDE activity in the membranes prepared from the four different muscle tissues was not modified by diabetes. Similarly, physical training in normal and diabetic rats did not induce any significant changes in the low Km PDE activity in any of the tissues tested. This suggests that improvements in myocardial contractile function and in glucose homeostasis, as seen in diabetic rats submitted to endurance training, are not associated with changes in PDE.
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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) | 0.000 | 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".