EFFECT OF CORTISOL TREATMENT ON FREE AMINO ACID LEVELS IN RATS

1973 ◽  
Vol 59 (1) ◽  
pp. 57-63 ◽  
Author(s):  
W. DE LOECKER ◽  
M. L. STAS

SUMMARY Changes in the concentrations of free amino acids in intracellular fluids and blood plasma were measured in rats treated with cortisol. Increasing age raised the concentrations of free amino acids in plasma, while in liver, with the exception of glycine and alanine, decreased concentrations were observed. Cortisol treatment reduced free amino acid levels in plasma and liver which suggested a progressive catabolism of body proteins and increased protein synthesis in the liver. In skeletal muscle of control rats the free amino acid concentrations increased during the experimental period. Cortisol increased the concentration of certain amino acids and decreased that of others due to an increased protein turnover in muscle.

1977 ◽  
Vol 232 (2) ◽  
pp. E243
Author(s):  
J B Li ◽  
L S Jefferson

The effect of isoproterenol on amino acid concentrations in perfusate and skeletal muscle was studied during a 3-h perfusion of the isolated rat hemicorpus. The beta-adrenergic agonist inhibited the accumulation of alanine, threonine, phenylalanine, tyrosine, lysine, arginine, leucine, and valine and increased the loss of glutamate, aspartate, serine, and isoleucine from the pool of free amino acids in perfusate and muscle. The loss of glutamate was accompanied by a greater accumulation of glutamine. Changes in alanine levels showed the greatest response with a net accumulation of 98 mumol in the controls becoming a net loss of 54 mumol in the experimentals. These changes in amino acid levels were accounted for in part by a 20% decrease in protein degradation. Protein synthesis was not affected by isoproterenol. In addition to an effect on degradation, it appeared that isoproterenol affected amino acid levels by increasing alanine utilization and causing formation of glutamine instead of alanine. Other effects of the drug included increased rates of lactate production, muscle glycogen breakdown, and oxygen consumption, whereas no effects were observed on ATP and creatine phosphate levels. Pyruvate content of muscle was maintained at a higher level in the presence of the drug than in control perfusions.


1976 ◽  
Vol 54 (11) ◽  
pp. 1927-1931 ◽  
Author(s):  
J. Alison Hanson ◽  
Thomas H. Dietz

Free amino acids constitute 11% of the cellular solute in Ligumia subrostrata acclimated in pond water but less than 1% of blood total solute. Arginine, glutamate, histidine, and alanine account for 60% of the cellular free amino acid concentration. Tissue free amino acid concentrations increase when the animals are exposed to dehydration and anoxic stress. Free amino acids contributing most to the elevated tissue amino acid concentrations are glutamate, alanine, threonine, and serine. These specific free amino acids play an important role in cellular volume regulation.


2002 ◽  
Vol 45 (3) ◽  
pp. 279-285
Author(s):  
E. Straková ◽  
P. Suchý ◽  
V. Večerek ◽  
L. Máchal

Abstract. The paper provides an overview of results obtained in the study of variation in free amino acid levels in the blood plasma of breeding roosters (RIR 05 line) during sexual maturation (in the 10th, 15th, 20th and 25th weeks of age). The results prove that dynamic changes in free amino acid concentrations in blood plasma are connected with the sexual maturation of breeding roosters. During this period the concentrations of each particular free amino acid varied at a significance level of P ≤ 0.05 and P ≤ 0.01. Furthermore, in most cases the plasma concentrations of free amino acids in the 10th and 15th week were higher in comparison with those in the 20th and 25th week. Interestingly, the concentrations of individual free amino acids ranged over a wide interval (units, tens and hundreds of μmol/l). In this respect the free amino acids in plasma can be divided into three groups. The first group consisted of amino acids that occurred at low molar concentration (up to 100 μmol/l): cysteic acid, aspartic acid, α-aminoadipic acid, methionine, isoleucine, γ-aminobutyric acid, 3-methylhistidine, tryptophan and ornitine. The second group included amino acids occurring at medium to high molar concentration (100–300 μmol/l): taurine, glutamine, 1/2 cystine, valine, leucine, tyrosine, phenylalanine, histidine, lysine and arginine. Finally, the third group contained threonine, serine, glutamic acid, proline, glycine and alanine that were present at high molar concentrations (above 300 μmol/l). Analyses of plasma in the period from the 10th to 25th week detected dynamic changes in levels of individual free amino acids and showed that the total content of these amino acids gradually decreased to the following mean values: 5 685.00 μmol/l in the 10th week, 5 076.21 μmol/l in the 15th week, 4 384.78 μmol/l in the 20th week and 4 793.30 μmol/l in the 25th week.


1980 ◽  
Vol 239 (6) ◽  
pp. G493-G496 ◽  
Author(s):  
E. J. Feldman ◽  
M. I. Grossman

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.


2021 ◽  
Vol 233 ◽  
pp. 02040
Author(s):  
Xuting Bai ◽  
Tao Li ◽  
Honglei Zhao ◽  
Xuepeng Li ◽  
Wenhui Zhu ◽  
...  

Protamex was selected to prepare the hydrolysate. E-tongue, free amino acid combined with soluble peptide analysis were used to detect the flavor changes of Aloididae aloidi during enzymolysis. Degree of proteolysis increased with the prolongation of enzymolysis time, and reached the maximum value at 8 hours. The content of soluble peptide of hydrolysate increased firstly and then decreased in the later process. The E-tongue could effectively distinguish the taste difference of hydrolysates at different enzymolysis time, and the hydrolysate presented strong bitterness and astringency during the whole enzymolysis. The total amount of free amino acids in the hydrolysate increased gradually, and some sweet, umami and bitter amino acids increased in varying degrees during the process of enzymolysis.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1637
Author(s):  
Quintino Reis de Araujo ◽  
Guilherme Amorim Homem de Abreu Loureiro ◽  
Cid Edson Mendonça Póvoas ◽  
Douglas Steinmacher ◽  
Stephane Sacramento de Almeida ◽  
...  

Free amino acids in cacao beans are important precursors to the aroma and flavor of chocolate. In this research, we used inferential and explanatory statistical techniques to verify the effect of different edaphic crop conditions on the free amino acid profile of PH-16 dry cacao beans. The decreasing order of free amino acids in PH-16 dry cacao beans is leucine, phenylalanine, glutamic acid, alanine, asparagine, tyrosine, gamma-aminobutyric acid, valine, isoleucine, glutamine, lysine, aspartic acid, serine, tryptophan, threonine, glycine. With the exception of lysine, no other free amino acid showed a significant difference between means of different edaphic conditions under the ANOVA F-test. The hydrophobic free amino acids provided the largest contribution to the explained variance with 58.01% of the first dimension of the principal component analysis. Glutamic acid stands out in the second dimension with 13.09%. Due to the stability of the biochemical profile of free amino acids in this clonal variety, it is recommended that cacao producers consider the genotype as the primary source of variation in the quality of cacao beans and ultimately the chocolate to be produced.


1969 ◽  
Vol 50 (2) ◽  
pp. 319-326
Author(s):  
R. R. HARRIS

1. Non-protein and protein nitrogen fractions of the isopod Sphaeroma rugicauda were measured in animals adapted to 100 and 2% sea water. 2. The non-protein nitrogen component was reduced in animals acclimatized to the lower salinity. 3. Free amino acids accounted for 88 and 74% respectively of the non-protein nitrogen in the two salinities. 4. In 2% sea water taurine, proline, glycine, alanine and glutamic acid showed the greatest decreases in concentration compared to the levels measured in animals adapted to 100% sea water. 5. The decrease in total free amino acids of animals acclimatized to 100% sea water and transferred to 2% sea water was measured. 6. The total free amino acid concentration is reduced to the 2% sea water level within 12 hr. after transfer. 7. Free amino acid, haemolymph sodium and total body sodium levels after transfer to 2% sea water were compared. 8. The asymmetry between the fall in haemolymph sodium concentration and the decrease in total body sodium under these conditions is thought to be due to a water shift from the haemolymph into the tissues. 9. It is suggested that the osmotic pressure of the cells falls at a slower rate than that of the haemolymph.


1987 ◽  
Vol 17 (1) ◽  
pp. 27-30 ◽  
Author(s):  
Y. T. Kim ◽  
C. Glerum ◽  
J. Stoddart ◽  
S. J. Colombo

Greenhouse-grown black spruce and jack pine container seedlings were fertilized weekly with a 20–8–20 fertilizer at four concentrations during the fall. Seedlings were sampled when 23 weeks old towards the end of the greenhouse cultural period to determine the effect of fertilization on the free amino acid concentrations. All amino acids, except tryptophan, showed significant increases in concentration with higher levels of fertilizer; the concentration of tryptophan decreased with increasing fertilizer concentration. Amino acids with the highest concentrations in black spruce were arginine, glutamic acid, and proline, while in jack pine, besides these three, aspartic acid and glutamine were also found in high concentrations. Black spruce had significantly higher amino acid concentrations than jack pine. The concentrations of certain free amino acids may be more sensitive indicators of seedling nitrogen status than total foliar nitrogen.


1956 ◽  
Vol 9 (4) ◽  
pp. 539 ◽  
Author(s):  
JV Possingham

The lovel and the qllHnj~itat,jve compositien of the free amino acid fraction of tomato plants grown in full nutrient and in cultures doficiollt ill zinc, copper, nlallganeso, iron. and molybdenum have beon cletormiuecl. 'I'he methods used in the investigation inelude the quantitative estimation of amino aeids by a technique involving paper chromatogl'l1phy, and the cultm'o of tomato plants in highly purified n utriollt solutions.


1981 ◽  
Vol 8 (2) ◽  
pp. 113-116 ◽  
Author(s):  
Harold E. Pattee ◽  
Clyde T. Young ◽  
Francis G. Giesbrecht

Abstract Peanuts from a commercial source were segregated into specific seed sizes and placed in storage conditions approximating commercial conditions to determine the amino acid changes taking place during storage within various size seeds. Concentrations of the isolated free amino acid fractions significantly decreased with seed size except for phenylalanine which significantly increased with seed size. Significant changes also occurred in the free amino acid fractions across storage periods up to nine months in duration. These results are the first to document a change in amino acids during the storage of peanuts.


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