Effects of Acute Aspartame Ingestion on Large Neutral Amino Acids and Monoamines in Rat Brain

Aspartame ◽  
2020 ◽  
pp. 641-653
Author(s):  
John D. Fernstrom
Keyword(s):  
Amino Acids ◽  
Rat Brain ◽  
Large Neutral Amino Acids ◽  
Neutral Amino Acids

Atypical amino acids inhibit histidine, valine, or lysine transport into rat brain

1983 ◽  
Vol 245 (4) ◽  
pp. R556-R563 ◽  
Author(s):  
J. K. Tews ◽  
A. E. Harper
Keyword(s):  
Amino Acids ◽  
Rat Brain ◽  
Blood Brain Barrier ◽  
Brain Slices ◽  
Aromatic Amino Acids ◽  
Brain Barrier ◽  
Basic Amino Acids ◽  
Large Neutral Amino Acids ◽  
Neutral Amino Acids ◽  
Single Meal

Transport of histidine, valine, or lysine into rat brain slices and across the blood-brain barrier (BBB) was determined in the presence of atypical nonprotein amino acids. Competitors of histidine and valine transport in slices were large neutral amino acids including norleucine, norvaline, alpha-aminooctanoate, beta-methylphenylalanine, and alpha-aminophenylacetate. Less effective were aromatic amino acids with ring substituents; ineffective were basic amino acids and omega-amino isomers of norleucine and aminooctanoate. Lysine transport was moderately depressed by homoarginine or ornithine plus arginine; large neutral amino acids were also similarly inhibitory. Histidine or valine transport across the BBB was also strongly inhibited by large neutral amino acids that were the most effective competitors in the slices (norvaline, norleucine, alpha-aminooctanoate, and alpha-aminophenylacetate); homoarginine and 8-aminooctanoate were ineffective. Homoarginine, ornithine, and arginine almost completely blocked lysine transport, but the large neutral amino acids were barely inhibitory. When rats were fed a single meal containing individual atypical large neutral amino acids or homoarginine, brain pools of certain large neutral amino acids or of arginine and lysine, respectively, were depleted.

Acute effects of aspartame on large neutral amino acids and monoamines in rat brain

Life Sciences ◽  
1983 ◽  
Vol 32 (14) ◽  
pp. 1651-1658 ◽  
Author(s):  
John D. Fernstrom ◽  
Madelyn H. Fernstrom ◽  
Marcia A. Gillis
Keyword(s):  
Amino Acids ◽  
Rat Brain ◽  
Acute Effects ◽  
Large Neutral Amino Acids ◽  
Neutral Amino Acids

Effects of carbohydrate and protein administration on rat tryptophan and 5-hydroxytryptamine: differential effects on the brain, intestine, pineal, and pancreas

1988 ◽  
Vol 66 (5) ◽  
pp. 683-688 ◽  
Author(s):  
Karen L. Teff ◽  
Simon N. Young
Keyword(s):  
Amino Acids ◽  
Rat Brain ◽  
Tryptophan Metabolism ◽  
Intragastric Administration ◽  
Acute Effects ◽  
Protein Meal ◽  
Differential Effects ◽  
Large Neutral Amino Acids ◽  
Neutral Amino Acids ◽  
The Brain

We compared the acute effects of intragastric administration of protein and carbohydrate on tryptophan and 5-hydroxytryptamine (5HT) in rat brain, pineal, intestine, and pancreas. Protein decreased and carbohydrate increased brain indoles relative to water-infused controls. These effects were due to competition between the large neutral amino acids for entry into the brain. This competition does not exist in the pineal. The macronutrients had no effect on pineal tryptophan metabolism. In the intestine, protein resulted in higher tryptophan levels as compared to controls, owing to absorption of tryptophan in the protein. However intestinal 5HT levels were influenced by factors other than precursor availability. Pancreatic indoles were affected in a similar manner to the brain indoles. Competition between the large neutral amino acids for entry into the pancreas was also indicated by the finding that valine administration lowered brain and pancreatic tryptophan, but not the levels in the intestine and pineal. It remains to be seen whether the decrease in pancreatic 5HT after a protein meal and the increase after carbohydrate modulate the release of insulin and glucagon.

scholarly journals Large Neutral Amino Acids (LNAAs) Supplementation Improves Neuropsychological Performances in Adult Patients with Phenylketonuria

Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1092 ◽  
Author(s):  
Iris Scala ◽  
Maria Pia Riccio ◽  
Maria Marino ◽  
Carmela Bravaccio ◽  
Giancarlo Parenti ◽  
...  
Keyword(s):  
Amino Acids ◽  
Executive Functions ◽  
Metabolic Control ◽  
Cognitive Functions ◽  
Well Being ◽  
Wisconsin Card Sorting Test ◽  
Card Sorting ◽  
Large Neutral Amino Acids ◽  
Neutral Amino Acids ◽  
Poor Metabolic Control

Phenylketonuria is an inborn error of phenylalanine (Phe) metabolism diagnosed by newborn screening and treated early with diet. Although diet prevents intellectual disability, patients often show impairment of executive functions, working memory, sustained attention, and cognitive flexibility. Large neutral amino acids (LNAAs) have been proposed as a dietary supplement for PKU adults. Few studies show that LNAAs may help in improving metabolic control as well as cognitive functions. In this study, 10 adult PKU patients with poor metabolic control were treated for 12 months with LNAAs (MovisCom, 0.8–1 g/kg/day) and underwent Phe and Tyrosine (Tyr) monitoring monthly. Neuropsychological assessment was performed at T0, T+3, and T+12 months by using the American Psychological General Well-Being Index, the Wisconsin Card Sorting Test, the Test of Attentional Performance, and the 9-Hole Peg Test. No change in plasma Phe levels was observed during LNAAs supplementation, while Tyr levels significantly improved during LNAAs supplementation (p = 0.03). Psychometric tests showed an improvement of distress and well-being rates, of executive functions, attention, and vigilance, whereas no difference was noted regarding hand dexterity. This study adds evidence of the advantage of LNAAs supplementation in improving cognitive functions and well-being in patients with PKU with poor metabolic control.

scholarly journals Trans-placental Gradients of Large Neutral Amino Acids (LNAA) in Baboon Pregnancy With Fasting,Feeding and Tryptophan (TRP) Infusion † 298

1998 ◽  
Vol 43 ◽  
pp. 53-53
Author(s):  
S Rastogi ◽  
K Abildskov ◽  
S S Daniel ◽  
M Garland ◽  
K Schulze ◽  
...  
Keyword(s):  
Amino Acids ◽  
Large Neutral Amino Acids ◽  
Neutral Amino Acids

Large neutral amino acids in the treatment of phenylketonuria (PKU)

2006 ◽  
Vol 29 (6) ◽  
pp. 732-738 ◽  
Author(s):  
R. Matalon ◽  
K. Michals-Matalon ◽  
G. Bhatia ◽  
E. Grechanina ◽  
P. Novikov ◽  
...  
Keyword(s):  
Amino Acids ◽  
Large Neutral Amino Acids ◽  
Neutral Amino Acids
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