PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “AMINO ACID MIXTURES”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed1979

Some lipogenic enzyme activities in rat livers in which an excessive fat accumulation occurred due to feeding low-level amino acid mixture diets.

In liver homogenates of rats fed a low-level diet of Wheat-Rice- or Miyazaki-pattern amino acid mixture, some enzymes such as glucose-6-phosphate dehydrogenase, ATP citrate lyase, fatty acid-synthesizing enzymes, malic enzyme and L-alpha-glycerophosphate dehydrogenase, whose activities are indicators of lipogenesis have been determined from the viewpoint of the mechanisms producing fatty liver. In the early experimental period, malic enzyme activity increased more markedly in rats fed low amino acid mixture diets than in the control group, and L-alpha-glycerophosphate dehydrogenase activity in the liver increased slightly. Conversely, ATP citrate lyase and fatty acid-synthesizing enzyme activities remained almost at control levels, or glucose-6-phosphate dehydrogenase activity tended to decrease. These results suggest that some other associated factors, such as depression of the lipid transfer system in the liver rather than accelerated lipogenesis itself, may be the main cause of the fatty livers produced under these nutritional conditions.

ATP Citrate (pro-S)-Lyase↗
PubMed1994

A new amino acid mixture permits new approaches to the treatment of phenylketonuria.

A new amino acid mixture for incorporation into medical foods for the treatment of hyperphenylalaninemia has been tested in a regular clinic. The mix is designed to be as unobtrusive as possible, consistent with good nutrition. After more than 1 year of trial as a beverage, we have shown that it is safe and well tolerated but that plasma phenylalanine is no better controlled than with some other products. The mix can be incorporated into a large number of different foods without affecting the taste. Occult monitoring of the quantity of medical foods purchased compared with the amounts reported to be consumed in diet histories provides an excellent way to monitor dietary compliance.

Amino Acids↗
PubMed2006

Amino acid mixture improves training efficiency in athletes.

This review discusses some of the beneficial effects of a dietary amino acid supplement on muscle function, fatigue, and recovery in exercising athletes. The supplement, a mixture of amino acids that included the branched-chain amino acids, arginine and glutamine, was studied chronically at several daily dose levels for extended periods of time (10, 30, and 90 d). Outcome variables included physical measures of muscle strength, fatigue and damage, and blood indices of muscle damage and oxygen-carrying capacity. One beneficial effect of the amino acid supplement was a quicker recovery from the muscle fatigue that followed eccentric exercise training. A dose-response study of the amino acid mixture at 2.2, 4.4, and 6.6 g/d for 1 mo showed that at the highest dose, indices of blood oxygen-carrying capacity were increased and those of muscle damage were decreased at the end of the trial. When the amino acid mixture was given for 90 d to elite rugby players during training at a dose of 7.2 g/d, a blood-component analysis indicated improvements in the oxygen-carrying capacity of the blood. Together, the studies suggest that the amino acid supplement contributed to an improvement in training efficiency through positive effects on muscle integrity and hematopoiesis.

Adult↗
PubMedDate not supplied

[The effect of autolysis on characteristics of amino acid mixtures, obtained using ethanol-assimilating yeasts].

The influence of the enzyme preparation - macerate, concentration of the yeast biomass in the reaction medium, and chloroform on the autolysis of the ethanol assimilating yeast Saccharomyces cerevisiae BKM-Y-2656, BKM-Y-2465, and the baker's yeast r. L-2 was studied. Amino acid mixtures were isolated from the yeast autolysates. The use of macerate and a decrease in the biomass concentration were shown to increase the yield of the amino acid mixtures. The use of chloroform positively influenced the baker's yeast autolysis. Conditions of the joint action of these factors on the intensification of the process of the amino acid mixtures preparation based on the autolysis were determined.

Amino Acids↗
PubMed2005

The effects of a branched chain amino acid mixture supplemented with tryptophan on biochemical indices of neurotransmitter function and decision-making.

RATIONALE: We have previously shown that a 60-g mixture of branched chain amino acids (BCAAs) lowers the plasma availability of the catecholamine precursors tyrosine (TYR) and phenylalanine (PHE) and produces biochemical and neuropsychological changes consistent with impaired dopamine neurotransmission. However, the BCAA mixture also lowers the ratio of tryptophan (TRP) to BCAA which could impair brain serotonin function. OBJECTIVES: To determine the biochemical and neuropsychological effects of a BCAA mixture supplemented with TRP. METHODS: We studied 32 healthy volunteers who were randomly and blindly allocated to either a single administration of amino acid mixture (60 g BCAA and 2 g TRP) or placebo. We carried out venous sampling to measure plasma levels of amino acids and performed selected cognitive tasks sensitive to monoamine manipulation 5 h after mixture ingestion. RESULTS: Relative to placebo, the BCAA/TRP mixture substantially lowered the ratio of TYR+PHE:BCAA and increased plasma prolactin. The ratio of TRP:BCAA was also lowered but to a lesser extent. The BCAA/TRP mixture produced significant changes in a task of decision-making where volunteers showed reduced discrimination between gambles with large and small losses. CONCLUSIONS: A 62 g BCAA/TRP mixture decreases the availability of TYR and PHE for brain catecholamine synthesis and increases plasma prolactin consistent with lowered brain dopamine function. Addition of 2 g TRP to the 60 g BCAA mixture does not prevent a reduction of the ratio TRP:BCAA relative to placebo. The effects of the BCAA/TRP mixture on decision-making suggest a general action of dopamine pathways on the processing of emotional information in risky choice, including punishment-related cues, consistent with suggestions that dopamine mechanisms mediate behavioural responses to aversive as well as appetitive stimuli in instrumental conditioning.

Adult↗
PubMedDate not supplied

[Correction of nitrogen metabolism in rats with toxic hepatitis by parenteral administration of an amino acid mixture].

The nitrogen metabolism in rats with toxic affection of the liver caused by administration of CCl4 was studied as affected by the amino acid mixture moriamine S-2. It is established that with toxic hepatitis the nitrogen metabolism is sharply disturbed, especially during protein deficiency. The following evidences for this fact: a rise in the depth of the nitrogen negative balance, an increase in the intensity of amine nitrogen and ammonia excretion with urea as well as an increase in the amount of amine nitrogen in blood and tissues with a simultaneous decrease in the content of protein. The parenteral administration of the amino acid mixture for eight days to the animals with a toxic affection of the liver is more effective when nitrogen preparation is combined with the group B vitamin, vitamin C, insulin, nerobolyl and sirepar.

Amino Acids↗
PubMed1991

Cycloheximide blocks the fall of plasma and tissue tryptophan levels after tryptophan-free amino acid mixtures.

The hypothesis that incorporation of tryptophan (TRY) into proteins is the mechanism underlying the decrease in plasma and tissue TRY levels after a TRY-free amino acid mixture was investigated. Rats fasted 15 hours were pretreated with saline or with the protein synthesis inhibitor cycloheximide (CHEX) and treated with saline or a TRY-free amino acid mixture. In a first experiment, in saline pretreated rats the TRY-free mixture caused a decrease of 49% in total plasma TRY, of 64% in free plasma TRY, of 66% in brain TRY and of 42% in liver TRY. After 5 mg/kg of CHEX the same TRY-free diet caused a decrease of 5% in total plasma TRY, 14% in free plasma TRY, 18% in brain TRY and 9% in liver TRY. In a second experiment, the TRY-free diet caused a 43% decrease of total plasma TRY in saline pretreated animals and a decrease of 15%, 6% and 2% respectively after the pretreatment with 0.3, 1.0 and 5.0 mg/kg of CHEX. In brain TRY, the TRY-free diet caused a 62% decrease in saline pretreated rats and a decrease of 38%, 20% and 19% respectively after the pretreatment with 0.3, 1.0 and 5.0 mg/kg of CHEX. Since 5.0 mg/kg of CHEX almost completely block protein synthesis and since doses of CHEX from 0.3 to 5.0 mg/kg cause a dose-dependent inhibition of protein synthesis, our data support the hypothesis that protein synthesis is the mechanism through which TRY-free mixtures decrease TRY levels.

Amino Acids↗
PubMed1975

[Investigations on the utilisation of parenterally administered amino acids by premature and small-for-dates neonates. II. Investigations of elimination half life time, elimination constants, transfer and clearances of amino acids after short-time infusion of L-amino acid mixtures (author's transl)].

10 ml/kg body weight of a 5% standardized L-amino-acid-mixture was given within the first 25 days to 25 prematurely born infants of 32--37 weeks gestationale and 5 small-for-dates newborns. We studied the metabolic kinetics of these amino acids in the serum and calculated elimination half life time, elimination constants, clearance and transfer rates of the single amino acids. The results were correlated with sex, nutritional state and age. 5 additional experiments were performed with 3 prematurely born infants and 2 small-for-dates newborns. The following results were of special interests: 1. Nearly all amino-acids had half life times between 30 and 50 min. Ornithine and tryptophane were more (half life time: 70 and about 50 min, respectively) slowly eliminated, while arginine and glutamic acid had half life times of between 5 and 15 min. 2. There was no statistically significant differences between sexes. 3. Eutrophic prematures eliminated the amino acids much faster then the hypotrophic ones. 4. Hypotrophic premature infants showed slow elimination of nearly all amino acids compared with hypotrophic newborns. 5. The elimination of nearly all amino acids studied grew faster with increasing age. The most significant differences were registered between the 1st and 3rd weeks of life.

Age Factors↗
PubMed2005

Co-ingestion of a protein hydrolysate and amino acid mixture with carbohydrate improves plasma glucose disposal in patients with type 2 diabetes.

BACKGROUND: Although insulin secretion after carbohydrate ingestion is severely impaired in patients with type 2 diabetes, amino acid and protein co-ingestion can substantially increase plasma insulin responses. OBJECTIVE: We investigated insulin responses and the subsequent plasma glucose disposal rates after the ingestion of carbohydrate alone (CHO) or with a protein hydrolysate and amino acid mixture (CHO+PRO) in patients with a long-term diagnosis of type 2 diabetes. DESIGN: Ten type 2 diabetic patients [mean (+/-SEM) age: 62 +/- 2 y; body mass index (kg/m(2)): 27 +/- 1] and 9 healthy control subjects (age: 58 +/- 1 y; body mass index: 27 +/- 1) participated in 2 trials in which the plasma insulin response was measured after the ingestion of 0.7 g carbohydrate . kg(-1) . h(-1) with or without 0.35 g . kg(-1) . h(-1) of a mixture that contained a protein hydrolysate, leucine, and phenylalanine. Continuous infusions with [6,6-(2)H(2)]glucose were then given to investigate plasma glucose disposal. RESULTS: Plasma insulin responses were higher by 299 +/- 64% and 132 +/- 63% in the CHO+PRO trial than in the CHO trial in the diabetic patients and the matched control subjects, respectively (P < 0.001). The subsequent plasma glucose responses were reduced by 28 +/- 6% and 33 +/- 3% in the CHO+PRO trial than in the CHO trial in the diabetic patients and the matched control subjects, respectively (P < 0.001). The reduced plasma glucose response in the diabetic patients was attributed to a 13 +/- 3% increase in glucose disposal (P < 0.01). CONCLUSIONS: The combined ingestion of carbohydrate with a protein hydrolysate and amino acid mixture significantly increases de novo insulin production in patients with a long-term diagnosis of type 2 diabetes. The increased insulin response stimulates plasma glucose disposal and reduces postprandial glucose concentrations.

Blood Glucose↗
PubMedDate not supplied

[Effect of muscular activity and administration of amino acid mixture on protein synthesis in rat skeletal muscles].

The mechanisms were studied determining the protein synthesis intensification in the skeletal muscles of albino rats during systematic physical activity only and in combination with enteroadministration of amino acid mixture. It is shown that systematic physical activity induces an increase in the RNA content in the skeletal muscles along with the lack of differences in specific radioactivity of microsomal, ribosomal and poly-A-containing mRNA. Supplementary administration of amino acid mixture in combination with the systematic physical activity induces a further increase in the skeletal muscle RNA content along with a decrease in specific radioactivity of poly-A-containing mRNA, parallel with an increase in its portion in microsomal RNA, as well as results in shifts of the ribosomal spectrum towards polysomal complexes.

Amino Acids↗
PubMed1977

Effect of glycylglycine on absorption from human jejunum of an amino acid mixture simulating casein and a partial enzymic hydrolysate of casein containing small peptides.

1. A jejunal perfusion technique has been used in normal volunteer subjects to study jejunal absorption of amino acid residues from a partial enzymic hydrolysate of casein in which about 50% of the amino acids existed as small peptides, and also from an equivalent mixture of free amino acids. 2. The effect of a high concentration of the dipeptide glycylglycine on the absorption of amino acid residues from these preparations was studied to quantify the importance of mucosal uptake of intact peptides during absorption of the partial hydrolysate of casein. 3. The results were unexpected. Glycylglycine significantly inhibited absorption of several amino acid residues (aspartic acid + asparagine, serine, glutamic acid + glutamine, proline, alanine, phenylalanine, threonine and isoleucine) from the free amino acid mixture, whereas it significantly inhibited the absorption of only two (serine, glutamin acid + glutamine) from the peptide-containing partial casein hydrolysate. 4. The effect of glycylglycine on absorption of amino acids from the mixture of free amino acids was apparently due to inhibition of amino acid uptake by free glycine liberated from the dipeptide during perfusion. The reason for the failure of glycylglycine to cause extensive inhibition of absorption from the partial hydrolysate is not clear. It may be due to glycylglycine being only a weak inhibitor of peptide uptake, but the possibility that some peptides are taken up by a system unavailable to glycylglycine has to be considered.

Adult↗
PubMedDate not supplied

[Effect of ultrasonic treatment on the intensification of processes for obtaining amino acid mixtures from ethanol-assimilating yeasts].

We studied the effects of ultrasound treatment on an increase of the yield of amino acid mixtures from autolysates of Saccharomyces cerevisiae VKM-Y-2465 grown on ethanol. Adding 2% chloroform (activating agent), autolysis for 5-10 h, and ultrasound treatment of autolysates allowed us to obtain mixtures balanced in lysine, methionine, and tryptophan and containing up to 90% free amino acids.

Amino Acids↗
PubMed1979

Effect of feeding amino acid mixtures on lipid transport from rat liver as measured by liver perfusion.

The present study examined lipid transport from the liver by application of a perfusion technique in situ in rats fed diets consisting of a low level Wheat- or Rice- or Miyazaki-pattern amino acid mixture. The net release of hepatic lipids was directly estimated from analysis of the perfusate continuously circulated through the liver. The net release of triacylglycerol from the liver into the perfusate was much more severely inhibited in the Wheat-pattern diet group, and more depressed in the Rice-pattern diet group than in the control group, and slightly reduced in the Miyazaki-pattern diet group compared with the control. For serum lipoproteins fractionated by the Quick-Disc electrophoresis method, there was a significant decrease in the serum pre-beta lipoprotein fraction in all the rats of the Wheat-, Rice- and Miyazaki-pattern diet groups compared with the control. These observations provide firm support for the hypothesis that in rats given diets consisting of a low level of the Wheat-, Rice- and Miyazaki-pattern amino acid mixture, fatty liver may be produced mainly by an impaired transport of triacylglycerols from the liver.

Amino Acids↗