Large neutral amino acid supplementation as an alternative to the phenylalanine-restricted diet in adults with phenylketonuria: evidence from adult Pah-enu2 mice

Many phenylketonuria (PKU) patients cannot adhere to the severe dietary restrictions as advised by the European PKU guidelines, which can be accompanied by aggravated neuropsychological impairments that, at least in part, have been attributed to brain monoaminergic neurotransmitter deficiencies. Supplementation of large neutral amino acids (LNAA) to an unrestricted diet has previously been shown to effectively improve brain monoamines in PKU mice of various ages. To determine the additive value of LNAA supplementation to a liberalized phenylalanine-restricted diet, brain and plasma monoamine and amino acid concentrations in 10 to 16-month-old adult C57Bl/6 PKU mice on a less severe phenylalanine-restricted diet with LNAA supplementation were compared to those on a non-supplemented severe or less severe phenylalanine-restricted diet. LNAA supplementation to a less severe phenylalanine-restricted diet was found to improve both brain monoamine and phenylalanine concentrations. Compared to a severe phenylalanine-restricted diet, it was equally effective to restore brain norepinephrine and serotonin even though being less effective to reduce brain phenylalanine concentrations. These results in adult PKU mice support the idea that LNAA supplementation may enhance the effect of a less severe phenylalanine-restricted diet and suggest that cerebral outcome of PKU patients treated with a less severe phenylalanine-restricted diet may be helped by additional LNAA treatment.

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Meat and Bone Characteristics of Broiler Chickens Fed Groundnut Cake-Based Diets as Affected by Graded Dietary Supplements of Crystalline L- Lysine and DL- Methionine

JOURNAL OF ADVANCES IN AGRICULTURE ◽

10.24297/jaa.v6i1.5392 ◽

2016 ◽

Vol 6 (1) ◽

pp. 846-852

Author(s):

Olugbenga Adeniran Ogunwole ◽

B. C Majekodunmi ◽

R. A Faboyede ◽

D. Ogunsiji

Keyword(s):

Amino Acid ◽

Broiler Chickens ◽

Bone Development ◽

Thiobarbituric Acid ◽

Broiler Chicks ◽

Amino Acid Supplementation ◽

Acid Supplementation ◽

Groundnut Cake ◽

Randomized Design ◽

Phosphorus And Potassium

Effects of supplemental dietary lysine and methionine in a Groundnut Cake (GNC) based diets on meat and bone characteristics of broiler chickens were investigated. In a completely randomized design, a total of 168 one - day â€“ old Arbor acre broiler chicks were randomly allocated to seven dietary treatments each in triplicate of eight birds per replicate. The Seven starter and finishersâ€™ diets were: GNC based diets without any amino acid (lysine or methionine) supplementation (T1); GNC diet + 0.2% lysine (T2); GNC diet + 0.4% lysine (T3); GNC diet + 0.2% methionine (T4); GNC diet + 0.4% methionine (T5); GNC diet + 0.2 lysine and 0.2% methionine (T6) and GNC diet + 0.4% lysine and 0.4% methionine (T7). Experimental diets and water were offered to birds ad libitum in an experiment lasting six-week. At day 42, two birds per replicate were slaughtered, meat and bone characteristics determined. There were significant variations (P<0.05) in the crude protein (%) and ether extract (%), pH1 and pH2 of meat. Thiobarbituric acid reactive substances composition of meat at days 0, 5, and 10 were similar (P<0.05) and were not affected by dietary amino acid supplementation. Tibiotarsal index (mg/mm) of bone (22.10, 27.25, 33.35, 31.40, 28.70, 31.45 and 29.75 for broilers on T1, T2, T3, T4, T5, T6 and T7, respectively) were increased significantly (P<0.05) by amino acid supplementation. Significantly differences (P<0.05) were observed in the calcium, phosphorus and potassium (%) contents of broilersâ€™ bone across treatments. Supplemental lysine and both lysine and methionine improved meat quality and bone development of broiler chickens in this study.

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