The effects of large neutral amino acid supplements in PKU: An MRS and neuropsychological study

Schindeler, Suzanne; Ghosh-Jerath, Suparna; Thompson, Susan; Rocca, Antonella; Joy, Pamela; Kemp, Allan; Rae, Caroline; Green, Kathryn; Wilcken, Bridget; Christodoulou, John

doi:10.1016/j.ymgme.2007.02.002

Cited by 106 publications

(109 citation statements)

References 20 publications

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“…Similar reductions in phenylalanine concentration in plasma or brain have been reported in subjects with PKU given supplementation with threonine (16) or mixtures of LNAAs (17)(18)(19). Competition among LNAAs, including threonine and isoleucine, with phenylalanine for intestinal absorption and transport across the blood-brain barrier may explain the observed reductions in phenylalanine (19,20).…”

Section: Introductionsupporting

confidence: 63%

Improved nutritional management of phenylketonuria by using a diet containing glycomacropeptide compared with amino acids

Calcar

MacLeod

Gleason

et al. 2009

The American Journal of Clinical Nutrition

115

123

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Background: Phenylketonuria (PKU) requires a lifelong lowphenylalanine diet that provides the majority of protein from a phenylalanine-free amino acid (AA) formula. Glycomacropeptide (GMP), an intact protein formed during cheese production, contains minimal phenylalanine. Objective: The objective was to investigate the effects of substituting GMP food products for the AA formula on acceptability, safety, plasma AA concentrations, and measures of protein utilization in subjects with PKU. Design: Eleven subjects participated in an inpatient metabolic study with two 4-d treatments: a current AA diet (AA diet) followed by a diet that replaced the AA formula with GMP (GMP diet) supplemented with limiting AAs. Plasma concentrations of AAs, blood chemistries, and insulin were measured and compared in AA (day 4) and GMP diets (day 8). Results: The GMP diet was preferred to the AA diet in 10 of 11 subjects with PKU, and there were no adverse reactions to GMP. There was no significant difference in phenylalanine concentration in postprandial plasma with the GMP diet compared with the AA diet. When comparing fasting with postprandial plasma, plasma phenalyalanine concentration increased significantly with the AA but not with the GMP diet. Blood urea nitrogen was significantly lower, which suggests decreased ureagenesis, and plasma insulin was higher with the GMP diet than with the AA diet. Conclusions: GMP, when supplemented with limiting AAs, is a safe and highly acceptable alternative to synthetic AAs as the primary protein source in the nutritional management of PKU. As an intact protein source, GMP improves protein retention and phenylalanine utilization compared with AAs.

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Section: Introductionsupporting

confidence: 63%

Improved nutritional management of phenylketonuria by using a diet containing glycomacropeptide compared with amino acids

Calcar

MacLeod

Gleason

et al. 2009

The American Journal of Clinical Nutrition

115

123

View full text Add to dashboard Cite

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“…It is postulated that supplementation with large doses of LNAAs with the exception of phenylalanine would reduce the entry of phenylalanine into the brain (Matalon et al 2007). Schindeler et al (2007) demonstrated a modest decrease in plasma Phe in patients with PKU not taking medical formula but no effect in those taking medical formula. This suggests LNAA therapy may be most beneficial for those unable to comply with dietary restrictions.…”

Section: Treatment With Large Neutral Amino Acidsmentioning

confidence: 90%

“…Large neutral amino acids (LNAAs) (phenylalanine, tyrosine, tryptophan, threonine, isoleucine, leucine, valine, methionine, arginine, lysine, and histidine) share the same cationic transporter protein to cross the blood brain barrier (Matalon et al 2007;Schindeler et al 2007). These amino acids compete for access to the same transporter protein and are driven by a concentration gradient.…”

Section: Treatment With Large Neutral Amino Acidsmentioning

confidence: 99%

Correlation of age‐specific phenylalanine levels with intellectual outcome in patients with phenylketonuria

Viau

Wengreen

Ernst

et al. 2011

J of Inher Metab Disea

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This study includes data collected from a retrospective chart review of patients with phenylketonuria treated at the University of Utah Metabolic Clinic. Among the approximately 175 patients treated for phenylketonuria at this clinic, 55 patients (28 female) met the inclusion criteria for the present study. Based on the diagnostic Phe level, 66.7% were classified as having classic phenylketonuria, 18.5% with moderate phenylketonuria, and 14.8% with mild phenylketonuria.

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“…Качественный и количественный состав аминокислот спе-циализированного продукта, определяющий его биологи-ческую ценность, способен повлиять на аминокислотный спектр крови [10]. Так, было показано, что фенилаланин, относящийся к классу больших нейтральных аминокислот, конкурирует с другими эссенциальными кислотами это-го же класса при проникновении через гематоэнцефали-ческий барьер [11,12]. Примечание.…”

Section: обсуждение основного результата исследованияunclassified

Results of a Prospective Study Concerning the Clinical Efficiency of Recent Russian-Made Specialized Foods without Phenylalanine

Бушуева¹,

Боровик²,

Ladodo³

et al. 2016

Pediatr. farmakol.

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The effects of large neutral amino acid supplements in PKU: An MRS and neuropsychological study

Cited by 106 publications

References 20 publications

Improved nutritional management of phenylketonuria by using a diet containing glycomacropeptide compared with amino acids

Improved nutritional management of phenylketonuria by using a diet containing glycomacropeptide compared with amino acids

Correlation of age‐specific phenylalanine levels with intellectual outcome in patients with phenylketonuria

Results of a Prospective Study Concerning the Clinical Efficiency of Recent Russian-Made Specialized Foods without Phenylalanine

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