Tyrosine-free amino acid mixture attenuates amphetamine-induced displacement of [11C]raclopride in striatum in vivo: A rat PET study

Synapse ◽  
2003 ◽  
Vol 51 (2) ◽  
pp. 151-157 ◽  
Author(s):  
Marisa Le Masurier ◽  
Gavin Houston ◽  
Philip Cowen ◽  
Paul Grasby ◽  
Trevor Sharp ◽  
...  
Keyword(s):  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino ◽  
Amino Acid Mixture ◽  
Acid Mixture

Acute administration of a tryptophan-free amino acid mixture decreases 5-HT release in rat hippocampus in vivo

1997 ◽  
Vol 272 (3) ◽  
pp. R991-R994 ◽  
Author(s):  
R. Stancampiano ◽  
F. Melis ◽  
L. Sarais ◽  
S. Cocco ◽  
C. Cugusi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Oral Administration ◽  
Free Amino Acid ◽  
Free Amino ◽  
Dorsal Hippocampus ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Acute Administration ◽  
The Brain

The effect of oral administration of a tryptophan-free amino acid mixture or the same mixture containing tryptophan (Trp) on hippocampal serotonin (5-HT) extracellular levels was studied using in vivo brain microdialysis of freely moving rats. During chloral hydrate anesthesia rats were implanted with dialysis probes in the dorsal hippocampus, and experiments were performed 24 h later. In vehicle-treated rats, the extracellular levels of 5-hydroxyindolacetic acid (5-HIAA) and 5-HT did not change during 240 min after ingestion. Oral administration of the Trp-free amino acid mixture significantly decreased basal 5-HT and 5-HIAA output 100 min after ingestion (65 and 81% of basal value, respectively) and remained at this level for another 140 min. The amino acid mixture containing Trp failed to significantly change basal extracellular levels of 5-HT, but enhanced that of 5-HIAA by approximately 134%. Moreover, in rats receiving the Trp-free amino acid mixture, the increase of hippocampal 5-HT release induced by d-fenfluramine (206%) was smaller than that released by the same drug in rats receiving the nutritionally balanced amino acid mixture (271%). Thus these results show that removal of Trp from the balanced amino acid mixture decreases spontaneous and d-fenfluramine-induced release of 5-HT in the hippocampus. In conclusion, our study supports the hypothesis that the mood-lowering effect observed in man after ingestion of a Trp-free amino acid mixture is associated with diminished 5-HT release in the brain.

Amino acid and dipeptide absorption in rats fed chemically defined diets of differing fiber composition

1984 ◽  
Vol 62 (9) ◽  
pp. 1097-1101 ◽  
Author(s):  
Hugh James Freeman
Keyword(s):  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino ◽  
Protein Energy Malnutrition ◽  
Amino Acid Mixture ◽  
Peptide Transport ◽  
Acid Mixture ◽  
Disease States ◽  
Protein Energy

In rats chronically fed a fiber-free diet or one of the three nutritionally equivalent fiber-containing diets, in vivo jejunal absorption of L-leucine from a free amino acid mixture of L-leucine and glycine as well as equimolar solutions of the dipeptides, L-leucyl-glycine and glycyl-L-leucine, were compared. In addition, total and brush border amino peptidase activities for the two dipeptide substrates were examined in small bowel segments. With two of three fiber diet groups, absorption of L-leucine from the free amino acid solution was reduced without a detectable change in peptide transport or aminopeptidase activities. This investigation provides evidence that peptide transport mechanisms are relatively spared with long-term feeding of fiber-containing diets similar to observations recorded in disease states associated with protein-energy malnutrition.

Liver extract and its free amino acids equally stimulate gastric acid secretion

1980 ◽  
Vol 239 (6) ◽  
pp. G493-G496 ◽  
Author(s):  
E. J. Feldman ◽  
M. I. Grossman
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Secretion ◽  
Gastric Acid Secretion ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Liver Extract ◽  
Amino Acid Mixture ◽  
Acid Mixture

Using intragastric titration in dogs with gastric fistulas, dose-response studies were carried out with liver extract and with a mixture of amino acids that matched the free amino acids found in liver extract. All solutions were adjusted to pH 7.0 and osmolality to 290 mosmol x kg-1. Doses are expressed as the sum of the concentrations of all free amino acids. At each dose studied (free amino acid concentration: 2.8, 5.6, 11, 23, and 45 mM), acid secretion in response to the free amino acid mixture was not significantly different from that of liver extract. The peak response to both liver extract and the free amino acid mixture occurred with the 23-mM dose and represented about 60% of the maximal response to histamine. The serum concentrations of gastrin after liver extract and the amino acid mixture were not significantly different. It is concluded that in dogs with gastric fistula, gastric acid secretion and release of gastrin were not significantly different in response to liver extract and to a mixture of amino acids that simulated the free amino acid content of liver extract.

Dependence of the utilization of a phenylalanine-free amino acid mixture on different amounts of single dose ingested. A case report

1994 ◽  
Vol 153 (7) ◽  
pp. 501-503 ◽  
Author(s):  
M. -E. Herrmann ◽  
H. G. Brösicke ◽  
M. Keller ◽  
E. Monch ◽  
H. Helge
Keyword(s):  
Single Dose ◽  
Case Report ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino ◽  
Amino Acid Mixture ◽  
Acid Mixture

scholarly journals EFFECT OF HYDROCHLORIDE-FREE AMINO ACID MIXTURE ON GROWTH AND FOOD INTAKE IN RATS

1974 ◽  
Vol 20 (6) ◽  
pp. 431-436
Author(s):  
Hiroshi ITOH ◽  
Tetsuya KISHI ◽  
Masahiro EMA ◽  
Ichiro CHIBATA
Keyword(s):  
Amino Acid ◽  
Food Intake ◽  
Free Amino Acid ◽  
Free Amino ◽  
Amino Acid Mixture ◽  
Acid Mixture

scholarly journals Diet enrichment with a specific essential free amino acid mixture improves healing of undressed wounds in aged rats

2017 ◽  
Vol 96 ◽  
pp. 138-145 ◽  
Author(s):  
Giovanni Corsetti ◽  
Claudia Romano ◽  
Evasio Pasini ◽  
Emanuele Marzetti ◽  
Riccardo Calvani ◽  
...  
Keyword(s):  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Aged Rats

Intestinal Absorption of Oligopeptides in Cystinuria

1971 ◽  
Vol 41 (1) ◽  
pp. 23-33 ◽  
Author(s):  
A. M. Asatoor ◽  
M. R. Crouchman ◽  
A. R. Harrison ◽  
F. W. Light ◽  
L. W. Loughridge ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino ◽  
Intestinal Transport ◽  
Tolerance Test ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Test Technique ◽  
Rat Gut

1. The intestinal transport of oligopeptides containing either lysine or arginine has been compared with that of the corresponding free amino acids in six homozygous cystinuric patients and in six normal adult subjects by use of the oral tolerance test technique. 2. No difference was found in the absorption of lysine from l-lysylglycine and an equivalent mixture of free lysine and glycine. 3. In comparisons of serum increments of lysine and arginine after oral casein and an equivalent free amino acid mixture there was no difference in the case of lysine but rise of serum arginine was higher in three cystinuric patients after the whole protein than after the amino acids. 4. Studies of urinary piperidine and pyrrolidine output in a single cystinuric patient supported the results of the tolerance tests. 5. Absorption rates of the dipeptides l-lysylglycine and l-arginyl-l-aspartate from an isolated loop of rat gut are compared with those of an equivalent free amino acid mixture. No difference was found for the former peptide, but in the latter absorption rates of arginine were higher after the amino acid mixture.

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