Plasma Concentrations and Pharmacokinetics of Phenylalanine in Rats and Mice Administered Aspartame
Bibliographic record
Abstract
Aspartame (L-aspartyl-L-phenylalanine methyl ester) is an esterified, dipeptide sweetener that is rapidly and completely metabolized in the gastrointestinal tract to phenylalanine, aspartic acid and methanol. The pharmacokinetics of phenylalanine (PHE) and tyrosine (TYR) were examined following the administration of oral doses of aspartame (APM) to fasted male Sprague-Dawley rats (0, 50, 100, 200, 500 and 1,000 mg/kg) and CD-1 mice (0, 100, 200, 500, 1,000 and 2,000 mg/kg). Peak plasma PHE/large neutral amino acid (LNAA) ratios were calculated. Maximal plasma PHE and TYR concentrations were observed within 1 h after dosing and returned to baseline within 4-8 h in both species regardless of the dose of APM. Mean PHE Cmaxs ranged from 73.6 to 1,161 nmol/ml in the rat, and from 78.6 to 1,967 nmol/ml in the mouse. TYR Cmaxs ranged from 91.6 to 502 nmol/ml and from 89.2 to 792 nmol/ml in the rat and mouse, respectively. AUCs and Cmaxs were linear with dose in both species. Peak plasma PHE/LNAA ratios ranged from 0.112 to 1.117 in rats and from 0.121 to 1.769 in mice. Comparison of these ratios with those observed previously in humans indicates that rodents require a 2-6 times higher dose of APM than humans to produce similar increases in plasma PHE/LNAA ratios.
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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 | 0.000 | 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) | 0.000 | 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".