Amino acid content of rat renal cortex and the response to in vitro incubation

1979 ◽  
Vol 236 (4) ◽  
pp. F398-F404
Author(s):  
B. Blazer-Yost ◽  
R. Reynolds ◽  
S. Segal

The concentration of aspartic acid, threonine, serine, glycine, and alanine is significantly higher in newborn rat renal cortex than in the adult tissue, while phenylalanine and histidine are higher in the adult. When adult cortical slices are placed in bicarbonate buffer at room temperature for 20 min there is a 30-60% decrease in the levels of all amino acids except for lysine, which is slightly higher, and methionine and serine, which do not change. Under the same conditions, newborn cortical slices reveal a similar decrease in only glycine, tyrosine, histidine, and the branched-chain amino acids. On subsequent in vitro incubation of the cortical slices at 37 degrees C for 120 min the concentrations in adult tissue remain at the lower values observed on removal from buffer at room temperature except that glutamic acid, glycine, and lysine levels decrease further and serine increases to the concentration found in fresh tissue. Newborn tissue when incubated at 37 degrees C for 120 min shows amino acid concentrations comparable to unincubated fresh tissue for all except aspartic acid, glutamic acid, serine, and phenylalanine, which reach levels higher than unincubated tissue. The ability of newborn tissue to maintain amino acid pools may play a role in the enhanced transport of some amino acids resulting from preincubation at 37 degrees C (Reynolds et al. Science 184: 68-69, 1974; Reynolds and Segal, Biochim. Biophys. Acta 406: 513-525, 1976).

1972 ◽  
Vol 43 (6) ◽  
pp. 823-837 ◽  
Author(s):  
D. Burston ◽  
Jill M. Addison ◽  
D. M. Matthews

1. The characteristics of transport and hydrolysis of twenty-two dipeptides containing basic and acidic amino acids by rat ileal rings were investigated in vitro. The peptides included combinations of basic and neutral, basic and basic, basic and acidic, acidic and acidic, and acidic and neutral amino acids. 2. All peptides studied were removed intact from the bulk phase of the incubation medium, though, in general, only free amino acids appeared in the tissue. Uptake of one or both constituent amino acids was greater from the peptide than from the equivalent amino acid or amino acid mixture in the case of at least one peptide from each group and in eighteen of the twenty-two peptides studied. In general, there was no relationship between the extent of uptake of amino acids from peptides and the extent of their hydrolysis by the system. The results support the hypothesis that there is more than one mode of uptake of amino acids from peptides. 3. Hydrolysis of γ-glutamyl-l-glutamic acid by intact intestine or intestinal homogenate was slight, and intact peptide was taken up by the tissue. Uptake of free glutamic acid from this peptide was poor. Comparison of γ-glutamyl-l-glutamic acid with three other slowly hydrolysed dipeptides, glycyl-d-valine, sarcosylglycine and glycylsarcosine, suggested that all four were transported into the mucosal cells and hydrolysed intracellularly. The results indicate that the presence of a γ-linkage or a d-amino acid, or methylation of the free amino group as in sarcosylglycine, impair both transport and hydrolysis of peptide, but that attachment of a methyl group to the N of the peptide bond, as in glycylsarcosine, impairs hydrolysis but has no effect on peptide transport. 4. l-Aspartic acid and l-glutamic acid were extensively transaminated by the intestine, whether presented as free amino acids or in peptides. Evidence was obtained suggesting that production of alanine from aspartic acid resulted from direct transamination of aspartic acid with pyruvic acid, rather than from a sequence of two reactions involving aspartate and alanine aminotransferases. 5. The results show that more rapid uptake of amino acids from peptides than from free amino acids is not confined to peptides made up of neutral amino acids, and probably occurs with many small peptides. Uptake of lysine and the dicarboxylic amino acids, which are particularly slowly absorbed from free solution, was much greater from several dipeptides than from the free amino acids. The results suggest the importance of mucosal peptide uptake in protein absorption.


2019 ◽  
Vol 17 (1) ◽  
pp. 313-324 ◽  
Author(s):  
Marta Pikosz ◽  
Joanna Czerwik-Marcinkowska ◽  
Beata Messyasz

AbstractFilamentous green algae (FGA) frequently forms dense mats which can be either mono- or polyspecies. While various defense mechanisms of competition in algae are known, little is known about the interactions between different species of FGA. An experiment in controlled laboratory conditions was conducted to gather data on the changes in amino acids (AA) concentrations in FGA species in the presence of exudates from different other species. The aim of the present study was to identify the AA whose concentrations showed significant changes and to assess if the changes could be adaptation to stress conditions. The major constituents of the AA pool in Cladophora glomerata, C. fracta and Rhizoclonium sp. were Glutamic acid (Glu), Aspartic acid (Asp) and Leucine (Leu). In response to chemical stress, that is the increasing presence of exudates, a significant increase in the concentrations Proline (Pro) and Tryptophan (Trp) was noted. The increase in Proline levels was observed in C. fracta and Rhizoclonium in response to chemical stress induced by C. glomerata exudates. As the concentration of exudates increased in the medium, there was a progressive shift in the pattern of AA group in FGA.


1983 ◽  
Vol 49 (3) ◽  
pp. 395-399 ◽  
Author(s):  
Rachel Bielorai ◽  
Z. Harduf ◽  
B. Iosif ◽  
Eugenia Alumot

1. The apparent absorption values of individual amino acids from two samples of feather meal (FM) were determined in the lower ileum of chicks fed on diets containing magnesium ferrite as a marker.2. The average absorption values for FM amino acids were low, approximately 0.50, as compared with approximately 0.85 for soya bean, used as a control. Values for individual amino acids from FM differed distinctly, ranging from 0.20 to 0.70. Low values were obtained for aspartic acid, histidine, lysine, glutamic acid and cystine.3. An indication of the low absorption of the previously-mentioned amino acids was obtained by analysing the amino acid composition of the FM residues undigested by pepsin or pancreatin.4. The reasons for testing the apparent rather than the true absorption are discussed.


Author(s):  
A. I. Fedosov ◽  
V. S. Kyslychenko ◽  
O. M. Novosel

Introduction. Plant amino acids have an important impact on functioning of various systems and organs of human body. In addition, they possess a wide range of pharmacotherapeutic properties, improve the digestion and potentiate the activity of biologically active compounds present in plants. Thus, the search of plant species that contain a large complex of plant amino acids and are used as food is of current interest. Garlic (Allium sativum L.) from Alliaceae family is one of such plants, and has been used since ancient times for the treatment of various disorders.The aim of the study – to determine the composition and quantitative content of free and bound amino acids of garlic bulbs and leaves.Research methods. The amino acid composition was determined using the high-performance liquid chromatography (HPLC) method.Results and Discussion. 16 amino acids were detected in garlic bulbs as a result of the experiment. Arginine (3.04 %) and proline (1.56 %) were found to be accumulated infree state, while glutamic acid (10.59 %), aspartic acid (6.06 %) and arginine (5.94 %) prevailed in bound state. 15 free and 16 bound amino acids were identified and quantified in garlic leaves. Glutamic acid (2.11 %), leucine (1.79 %), valine (1.77 %), isoleucine (1.52 %), treonine and phenylalanine (1.44 %) dominated infree state, and glutamic acid (28.49 %), aspartic acid (12.90 %) and leucine (7.61 %) prevailed in bound state. Methionine was found only in bound state in garlic leaves.Conclusions. The amino acid composition of garlic bulbs and leaves was studied using the HPLC method. 16 amino acids in both free and bound state were detected and their content was determined in garlic bulbs, while in garlic leaves – 15 free and 16 bound amino acids. The results of the experiment showed that methionine is present only in bound state in garlic leaves.


1959 ◽  
Vol 37 (6) ◽  
pp. 957-964 ◽  
Author(s):  
J. E. J. Habowsky ◽  
R. W. Shuel

The protein constituents of the larval diets of queen and worker honeybees were separated by continuous paper electrophoresis. The electrophoretic patterns of royal jelly of any age and the early worker diet were similar and comprised five ninhydrin-reactive bands or fractions. Fraction 1 (nearest the cathode) contained lysine as a free amino acid. Fractions 3 and 4 appeared to be complex polypeptides. Alanine, asparagine, aspartic acid, glutamic acid, glycine, histidine, isoleucine and/or leucine, lysine, phenylalanine, threonine, tyrosine, valine, and an unidentified substance were found in chromatograms of the acid hydrolyzate of fraction 3; the hydrolyzate of fraction 4 contained the same amino acids except for threonine. Fractions 2 and 5 were not characterized. Electrophoresis of the diet of worker larvae older than 3 days showed a pronounced fading of all bands, attributable to the dilution of the solids by the addition of honey which occurs at this time. There appeared to be no qualitative differences between the protein fractions of royal jelly and worker diet which would account for the differentiation of female honeybees into queens and workers. The decrease with age in the percentage of protein in the worker diet may be significant.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Affiong Iyire ◽  
Maryam Alaayedi ◽  
Afzal R. Mohammed

Abstract The aim of this work was to investigate alternative safe and effective permeation enhancers for buccal peptide delivery. Basic amino acids improved insulin solubility in water while 200 and 400 μg/mL lysine significantly increased insulin solubility in HBSS. Permeability data showed a significant improvement in insulin permeation especially for 10 μg/mL of lysine (p < 0.05) and 10 μg/mL histidine (p < 0.001), 100 μg/mL of glutamic acid (p < 0.05) and 200 μg/mL of glutamic acid and aspartic acid (p < 0.001) without affecting cell integrity; in contrast to sodium deoxycholate which enhanced insulin permeability but was toxic to the cells. It was hypothesized that both amino acids and insulin were ionised at buccal cavity pH and able to form stable ion pairs which penetrated the cells as one entity; while possibly triggering amino acid nutrient transporters on cell surfaces. Evidence of these transport mechanisms was seen with reduction of insulin transport at suboptimal temperatures as well as with basal-to-apical vectoral transport, and confocal imaging of transcellular insulin transport. These results obtained for insulin are the first indication of a possible amino acid mediated transport of insulin via formation of insulin-amino acid neutral complexes by the ion pairing mechanism.


1956 ◽  
Vol 34 (6) ◽  
pp. 527-532 ◽  
Author(s):  
Ernest Hodgson ◽  
Vernon H. Cheldelin ◽  
R. W. Newburgh

Phormia regina grown on a chemically defined diet under sterile conditions has been shown to have a specific dietary requirement for choline. The present work shows that carnitine and 2,2-dimethylaminoethanol can completely replace this in the diet whereas betaine is ineffective in this respect. Deletion of single amino acids from a mixture of 18 adequate for growth has previously shown the following 10 amino acids to be essential: arginine, histidine, leucine, lysine, phenylalanine, threonine, tryptophan, valine, proline, and isoleucine. The present work: shows by the inability of the organism to grow on these essential amino acids that this method is not adequate to detect amino acid combinations for which alternate requirements exist. By the deletion of groups of two or more amino acids it has been shown that P. regina has a dietary requirement for either methionine or cystine and for either glutamic acid or aspartic acid. Growth on the 10 essential amino acids is stimulated by yeast extract. This is apparently not due to a simple replacement of missing amino acids, since the addition of yeast creates an increased requirement for thiamine.


1973 ◽  
Vol 51 (4) ◽  
pp. 323-331 ◽  
Author(s):  
C. Mavrides

The regulation of glyconeogenesis from amino acids by acetate was studied in Tetrahymena pyriformis. Alanine aminotransferase and glutamate dehydrogenase were repressed by 0.1% sodium acetate in the growth medium. Incorporations into the glycogen of washed cells from the respective isotopically labelled amino acids were similarly suppressed.Incorporations into glycogen from uniformly 14C-labelled L-serine, L-leucine, L-isoleucine, L-tyrosine, and DL-β-14C-tyrosine were also suppressed by prior growth in a medium supplemented with 0.1% or 0.3% acetate. Percentage incorporation into glycogen was highest from tyrosine, followed by leucine, isoleucine, and alanine, and lowest from glutamic acid and serine.Supplementation of the medium with 0.25% glucose resulted in repression of the above two enzymes and suppression of incorporation into glycogen from amino acids.Incorporation of aspartic acid into glycogen was negligible and was variously and minimally affected by growth in glucose- or acetate-supplemented media. Aspartate aminotransferase was affected in a like manner.Glycogen content was not significantly affected by growth in media supplemented with 0.1% or 0.3% acetate. On the whole, the data suggest that acetate spares amino acids for glyconeogenesis by a mechanism which entails repression of amino-acid-catabolizing enzymes.


1978 ◽  
Vol 91 (3) ◽  
pp. 717-725 ◽  
Author(s):  
T. N. Barry ◽  
D. N. Mundell ◽  
R. J. Wilkins ◽  
D. E. Beever

SummaryLucerne was made into ten silages using either a flail or a precision-chop harvester with application of formaldehyde or a range of rates of formic acid during harvesting. Amino-acid analyses were done on the silages and on samples taken from the herbage at ensiling.In excess of 70% of aspartic acid, serine, glutamic acid, tyrosine, threonine, lysine, histidine and arginine were destroyed in untreated silages when a flail harvester was used and in excess of 50% when a precision-chop harvester was used. Glycine, leucine, iso-leucine, valine and methionine showed little change, with net losses or increases of up to 10%, whilst proline, cystine + cysteine and phenylalanine were intermediate between these two categories. Net synthesis of alanine and α and γ amino-butyric acids occurred in the untreated silages. Increasing rates of formic acid addition, and the use of the precision-chop harvester, reduced the loss of the amino acids which were extensively degraded in the untreated silages and minimized the increases in alanine and α and γ amino-butyric acids. Formaldehyde treatment also reduced amino-acid degradation, apart from apparently high losses of lysine, histidine and tyrosine. It was concluded, however, that these losses arose through problems of estimation in formaldehyde-treated silages following HCl hydrolysis.It is suggested that the most probable precursors for alanine and α and γ aminobutyric acids were respectively aspartic acid, threonine and glutamic acid. Voluntary intake and the utilization of silage nitrogen by young sheep were related to the net changes in amino acids involved in decarboxylation reactions, the best measures of this being the interconversions involving the formation of alanine and α and γ aminobutyric acids. Deamination reactions appeared to be of much less importance in limiting silage nutritive value than those involving decarboxylation.


1972 ◽  
Vol 70 (2) ◽  
pp. 409-416 ◽  
Author(s):  
S. Jaszczak ◽  
E. S. E. Hafez

ABSTRACT Free amino acid content was measured in the uterine fluid and blood serum in the following groups of rabbits 168 h post copulation: intact; intact progesterone-treated; ovariectomized progesterone-treated; ovariectomized progesterone-oestradiol-treated; and ovariectomized without hormonal treatment. At implantation, concentration of the majority of amino acid in uterine fluid exceeded greatly that of blood serum; the difference in concentration being maximal for glycine, taurine, alanine, glutamic acid, aspartic acid, serine and threonine. Glutamine-asparagine and arginine were found in comparable quantities or were even higher in blood serum. Glycine, alanine, taurine, glutamic acid, serine and glutamine-asparagine were found in highest concentration in the uterine fluid. The level of ammonia in uterine fluid was also relatively high. Exogenous progesterone and oestradiol caused significant changes in the concentration of some amino acid. The concentration of glycine, taurine, alanine, serine, glutamic acid, aspartic acid, threonine, ½ cystine and histidine seems to be especially hormonally dependent. The results are discussed in relation to hormonal activity of corpora lutea during early pregnancy, physiological significance of free amino acids in uterine fluid and nourishment of an early embryo.


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