Journal of Neural Transmission

, Volume 70, Issue 1–2, pp 169–173 | Cite as

Effects of oral aspartame on plasma phenylalanine in humans and experimental rodents

  • R. J. Wurtman
  • T. J. Maher
Short Note


All aspartame does given to humans cause greater elevations in plasma (and, presumably, brain) phenylalanine than in plasma tyrosine. In contrast, doses of aspartame usually used in experiments on rodents preferentially elevate tyrosine. Since phenylalanine can inhibit brain catecholamine synthesis while tyrosine is the antidote for this effect, we determined the aspartame dose that would be needed to elevate phenylalanine more than tyrosine in rodents, using published data. In general rodents need 60 times as much aspartame, on a mg/kg basis, as humans to obtain comparable elevations in phenylalanine with respect to tyrosine.

Key words

Aspartame phenylalanine tyrosine 


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Copyright information

© Springer-Verlag 1987

Authors and Affiliations

  • R. J. Wurtman
    • 1
  • T. J. Maher
    • 2
  1. 1.Massachusetts Institute of TechnologyCambridge
  2. 2.Massachusetts College of PharmacyBostonUSA

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