Effects of Kuvan on Melatonin Secretion

Summary

This study examines the effect of tetrahydrobiopterin (Kuvan) and Large Neutral Amino Acid (LNAA) therapy on melatonin and dopamine levels in individuals with Phenylketonuria (PKU). The investigators hypothesize that Kuvan therapy will improve melatonin secretion and urine dopamine levels to some extent. However significantly greater responses in melatonin and dopamine secretions may be observed with combined treatment with Kuvan and supplementation of LNAA.

Timeline

Start

2012-05

Primary completion

2014-12

Completion

2014-12

Publications

• Background Kaufman S, Kapatos G, McInnes RR, Schulman JD, Rizzo WB. Use of tetrahydropterins in the treatment of hyperphenylalaninemia due to defective synthesis of tetrahydrobiopterin: evidence that peripherally administered tetrahydropterins enter the brain. Pediatrics. 1982 Sep;70(3):376-80.
• Background Schindeler S, Ghosh-Jerath S, Thompson S, Rocca A, Joy P, Kemp A, Rae C, Green K, Wilcken B, Christodoulou J. The effects of large neutral amino acid supplements in PKU: an MRS and neuropsychological study. Mol Genet Metab. 2007 May;91(1):48-54. doi: 10.1016/j.ymgme.2007.02.002. Epub 2007 Mar 23.
• Background Lou H. Large doses of tryptophan and tyrosine as potential therapeutic alternative to dietary phenylalanine restriction in phenylketonuria. Lancet. 1985 Jul 20;2(8447):150-1. doi: 10.1016/s0140-6736(85)90250-8. No abstract available.
• Background Nielsen JB, Lou H, Güttler F. Effects of diet discontinuation and dietary tryptophan supplementation on neurotransmitter metabolism in phenylketonuria. Brain Dysfunction 1:51-56. 1988.
• Background Zimmermann RC, McDougle CJ, Schumacher M, Olcese J, Heninger GR, Price LH. Urinary 6-hydroxymelatonin sulfate as a measure of melatonin secretion during acute tryptophan depletion. Psychoneuroendocrinology. 1993;18(8):567-78. doi: 10.1016/0306-4530(93)90034-i.
• Background Katz I, Lloyd T, Kaufman S. Studies on phenylalanine and tyrosine hydroxylation by rat brain tyrosine hydroxylase. Biochim Biophys Acta. 1976 Oct 11;445(3):567-78. doi: 10.1016/0005-2744(76)90111-x.
• Results Yano S, Moseley K, Fu X, Azen C. Evaluation of Tetrahydrobiopterin Therapy with Large Neutral Amino Acid Supplementation in Phenylketonuria: Effects on Potential Peripheral Biomarkers, Melatonin and Dopamine, for Brain Monoamine Neurotransmitters. PLoS One. 2016 Aug 11;11(8):e0160892. doi: 10.1371/journal.pone.0160892. eCollection 2016.

Drugs

Indications