AJCN Cancer Health Disparities Conference
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by van Spronsen, F. J.
Right arrow Articles by Heymans, H. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by van Spronsen, F. J.
Right arrow Articles by Heymans, H. S.
Agricola
Right arrow Articles by van Spronsen, F. J.
Right arrow Articles by Heymans, H. S.

American Journal of Clinical Nutrition, Vol 64, 916-921, Copyright © 1996 by The American Society for Clinical Nutrition, Inc

ORIGINAL RESEARCH COMMUNICATIONS

Large daily fluctuations in plasma tyrosine in treated patients with phenylketonuria

FJ van Spronsen, T van Dijk, GP Smit, M van Rijn, DJ Reijngoud, R Berger and HS Heymans
Beatrix Children's Hospital, University of Groningen, Netherlands.

In patients with phenylketonuria (PKU), extra tyrosine supplementation is advocated in addition to tyrosine-enriched amino acid mixtures. PKU patients have low fasting plasma tyrosine concentrations, but little is known about tyrosine fluctuations during the day. Plasma tyrosine concentrations were studied in 12 PKU patients in response to a test without breakfast and to three tests with different tyrosine contents in breakfast and lunch: 0%/30%, 25%/30%, 50%/10%, and 75%/10% tests, reflecting the protein consumption at breakfast and lunch, respectively. Prolonged fasting resulted in a small decrease in the already low overnight fasting plasma tyrosine concentrations. Breakfast and lunch with 25% and 30% of the daily tyrosine intake resulted in both lower than normal and higher than normal tyrosine concentrations. The 50%/10% and 75%/10% tests resulted in excessively high plasma tyrosine concentrations in most patients. Therefore, both lower than normal and higher than normal postprandial plasma tyrosine concentrations were found in treated PKU patients, even if the daily tyrosine intake was distributed evenly. When there was a large fractional tyrosine intake from one meal, very high plasma tyrosine concentrations were found. Therefore, strict control of plasma tyrosine is necessary if tyrosine supplementation is considered in addition to the tyrosine-enriched amino acid mixtures.


This article has been cited by other articles:


Home page
 Am. J. Clin. Nutr.Home page
F. J van Spronsen, M. van Rijn, J. Bekhof, R. Koch, and P. G. Smit
Phenylketonuria: tyrosine supplementation in phenylalanine-restricted diets
Am. J. Clinical Nutrition, February 1, 2001; 73(2): 153 - 157.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
R. Bross, R. O. Ball, J. T. R. Clarke, and P. B. Pencharz
Tyrosine requirements in children with classical PKU determined by indicator amino acid oxidation
Am J Physiol Endocrinol Metab, February 1, 2000; 278(2): E195 - E201.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Clin. Nutr.Home page
R. Artuch, M-A. Vilaseca, J. Moreno, N. Lambruschini, F. J Cambra, and J. Campistol
Decreased serum ubiquinone-10 concentrations in phenylketonuria
Am. J. Clinical Nutrition, November 1, 1999; 70(5): 892 - 895.
[Abstract] [Full Text] [PDF]

Home page
 J. Am. Coll. Nutr.Home page
P.B. Acosta, S. Yannicelli, B. Marriage, R. Steiner, B. Gaffield, G. Arnold, V. Lewis, S. Cho, L. Berstein, P. Parton, et al.
Protein Status of Infants with Phenylketonuria Undergoing Nutrition Management
J. Am. Coll. Nutr., April 1, 1999; 18(2): 102 - 107.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1996 by The American Society for Nutrition