The effects of creatine, lithium, and co-supplementation on total creatine concentration in muscle from male and female rats
Bibliographic record
Abstract
Creatine (Cr) is an element necessary to maintain muscle function in tissues with high energy demand. This is because Cr and phosphocreatine (PCr) play a critical role in cellular energy provision and intracellular shuttling through the Cr-PCr immediate energy system. Cr can be synthesized endogenously, as well as consumed exogenously via diet or supplementation. Literature supports the potential for increased Cr uptake to augment several factors of human performance – most namely muscle function in sports related to strength, speed, and power. Moreover, recent research suggests potential for lithium (Li) to upregulate Cr uptake and Cr transport into cells. Therefore, the purpose of this research was to investigate the individual and combined effects of creatine monohydrate (CM) and lithium chloride (LiCl) supplementation on Cr content in rat cardiac and skeletal muscle in vivo. Potential sex-specific effects were also explored. 64 Sprague-Dawley rats (32 males, 32 females) were randomized into four experimental groups: control (CON), creatine (Cr), lithium (Li), and creatine-lithium (Cr-Li). CM (5 g/L) and LiCl (0.2 g/L) were provided to rats via drinking water. All groups were provided ad libitum access to their respective drinking water (all supplemented with 0.5% sucrose for palatability) and AIN- 93G rodent diet. When males and females were examined together, intramuscular total creatine concentration ([TCr]) was greater (p<0.01) with CM supplementation compared to LiCl supplementation and tended to be greater (p=0.0706) than CON in cardiac muscle. There were no significant main effects for treatment in any of the skeletal muscle outcomes examined. A main effect for sex revealed that male rats had greater [TCr] than female rats, in extensor digitorum longus (EDL) (p<0.01). In soleus (SOL) and EDL, female rats had greater total glycogen synthase 3 beta (GSK3β) protein expression compared to males (p<0.05), but there were no significant effects of treatment observed. Protein content of the creatine transporter (CrT) was greater in males than females in cardiac muscle (p<0.05). It was also greater in CON rats compared to Li (p<0.01) and CrLi (p<0.05) supplemented rats, in SOL. In conclusion, supplementation with CM, with or without LiCl, altered TCr concentrations in a tissue-dependent manner.
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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 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".