Food Matrix Effects Do Not Differentially Phosphorylate Rps6 Versus The Sum Of Its Parts
Bibliographic record
Abstract
The mechanistic underpinnings of the post-exercise stimulation of muscle protein synthesis rates (MPS) are partly dependent on mTOR (mammalian target of rapamycin)-related signalling events. To date, most studies investigating the anabolic response to nutrient ingestion have employed isolated protein sources and free amino acid mixtures as the stimulus. However, this approach ignores the potential nutrient-nutrient interactions that could alter leucinemia (prime anabolic signal) when protein is consumed within its natural food matrix. Given those whole foods are the cornerstones of dietary patterns, investigating the food matrix regulation of muscle anabolic signalling is warranted. PURPOSE: To evaluate the food matrix effects on the regulation of post-exercise anabolic signalling by comparing salmon (SAL) to the ingestion of the same nutrients as an isolated mixture (ISO). METHODS: Nine recreationally-active adults (5 M, 4 F; age: 24 ± 4 y; BMI: 25.5 ± 2.2 kg·m-2) performed 4 sets of 10 repetitions at 90% of 10RM for both leg press and leg extension exercises on two occasions. In a randomized crossover design, participants ingested 20.6 g of protein from either SAL or ISO (sum of crystalline amino acids, fish oil, and coconut oil) immediately post-exercise. Arterialized blood samples were collected before (t = -210, -150, -90, -60, -30, -5 min) and after treatment ingestion (t = 15, 30, 45, 60, 75, 90, 105, 120, 150, 180, 210, 240 and 300 min). Muscle samples were collected before (t = -30 min) and after (120 min and 300 min) ingestion of SAL or ISO. The phosphorylation status of ribosomal protein S6 (rpS6Ser240/244) was assessed via Western Blot. RESULTS: The postprandial time to peak of plasma leucine concentrations was faster (P = 0.002) in ISO (46.7 ± 24.1 min) vs. SAL (86.3 ± 24.1 min) condition. Net exposure to plasma leucine was greater (P = 0.050) in SAL vs. ISO condition. Regardless of the condition (P = 0.775), rpS6 phosphorylation was significantly elevated above baseline at 120 min (P = 0.002) and 300 min (P = 0.049), with a significant difference between 120 and 300 min (P = 0.020). CONCLUSION: The salmon matrix does not differentially regulate rpS6 phosphorylation when compared to consuming the sum of its isolated parts. Supported by USDA National Institute of Food and Agriculture Hatch project 1017928.
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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) | 0.000 | 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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.005 | 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".