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Oral aspartame and plasma phenylalanine: pharmacokinetic difference between rodents and man, and relevance to CNS effects of phenylalanine

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Summary

The ingestion of aspartame, a phenylalanine-containing dipeptide, raises plasma phenylalanine levels. These increments are much greater in humans than rats, because the rat hydroxylates phenylalanine five times faster than man. Accordingly, dose comparisons of aspartame (or phenylalanine) between humans and rats have usually been corrected by a factor of five. Recently, a correction factor of sixty has been proposed (Wurtman and Maher, 1987); the rationale is based on a novel calculation of competitive phenylalanine transport into brain. An analysis of the logic behind this postulation reveals there to beno basis for accepting the higher dose conversion of 60 between rat and man.

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  1. J. D. Fernstrom

    Present address: Western Psychiatric Institute and Clinic, 3811 O'Hara Street, 15213, Pittsburgh, PA, USA

Authors and Affiliations

  1. Departments of Psychiatry and Behavioral Neuroscience and Center for Neuroscience, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA

    J. D. Fernstrom

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  1. J. D. Fernstrom
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Fernstrom, J.D. Oral aspartame and plasma phenylalanine: pharmacokinetic difference between rodents and man, and relevance to CNS effects of phenylalanine. J. Neural Transmission 75, 159–164 (1989). https://doi.org/10.1007/BF01677429

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  • DOI: https://doi.org/10.1007/BF01677429

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