The effects of exercise training on γ-butyrobetaine hydroxylase and novel organic cation transporter-2 gene expression in the rat
Bibliographic record
Abstract
The concentration of carnitine in plasma is generally increased with exercise training, suggesting that either carnitine biosynthesis is stimulated or renal reabsorption of carnitine is enhanced, or both. Carnitine, an essential cofactor in the oxidation of fatty acids, is released into the plasma following hydroxylation by γ-butyrobetaine hydroxylase (BBH), the final enzyme in the biosynthetic pathway found primarily in the liver. The organic cation transporter (OCTN2), the carnitine transporter found in kidney, is important in the distribution of carnitine by facilitating its renal reabsorption from urine. In this study, we tested the hypothesis that exercise training increases gene and protein expression of BBH and OCTN2, resulting in enhanced plasma carnitine levels. Male Wistar rats were subjected to 2 daily exercise sessions of treadmill running, 5 days per week, for a 10-week period. The concentration of total carnitine in plasma was significantly increased in trained rats compared with sedentary rats. In trained rats, mRNA and protein expression of BBH were increased in liver, whereas only BBH mRNA expression was increased in kidney. Liver of trained rats demonstrated increased mRNA and protein expression of OCTN2 compared with sedentary rats. In kidney of trained rats, however, only an increase in mRNA expression of OCTN2 was observed. Our results suggest that the improved plasma carnitine status in the trained rat is associated with increased carnitine biosynthesis in liver and kidney. The observation that OCTN2 expression was increased in kidney suggests a potential role of the kidney in the reabsorption of carnitine from the urine.
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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 | 0.001 |
| Bibliometrics | 0.001 | 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".