EFFECTS OF DIETARY UREA LEVEL ON AMINO ACID CONCENTRATIONS IN RUMINANT TISSUES

1973 ◽  
Vol 53 (4) ◽  
pp. 717-724 ◽  
Author(s):  
H. A. SALEM ◽  
T. J. DEVLIN ◽  
J. R. INGALLS ◽  
G. D. PHILLIPS
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Latin Square ◽  
Essential Amino Acids ◽  
Plasma Amino Acid ◽  
Isoleucine Leucine ◽  
Rumen Microorganisms ◽  
Rumen Epithelium ◽  
Amino Acid Concentrations

The effects of a semipurified diet containing 0 (0% urea-N diet), 50 (39% urea-N diet), or 100% (76% urea-N diet) of added dietary nitrogen (N) as urea on the amino acid concentrations in ruminant tissues was investigated. Three rumen-fistulated bull calves averaging 240 kg were used in a latin square design. The calves were fed using a continuous feeder to provide 7 kg of feed daily. Each experimental period of the latin square was 40 days divided into four 10-day intervals. Liver samples were obtained on the 9th day of each 10-day interval and rumen epithelium and rumen microorganisms were obtained on the 10th day of each 10-day interval. Blood samples were collected on the 6th, 8th, and 10th day of each 10-day interval for the determination of plasma amino acid patterns as well as the amino acid concentrations in the tissues. Plasma amino acid patterns indicated that when the 76% urea-N diet was fed the levels of aspartic acid, citrulline, glutamic acid, glycine, and proline were increased. Most of the essential amino acids were decreased on the 76% urea-N diet as compared with the 0% urea-N diet. All amino acids of rumen microorganisms were increased on the 39% urea-N diet with the exception of arginine, lysine, and threonine, which decreased slightly or did not show any change. Most amino acids were lower on the 76% urea-N diet as compared with the 39% or 0% urea-N diets. All essential amino acids measured in the liver were reduced on the 76% urea-N diet. Cystine, glutamic acid, glycine, isoleucine, leucine, lysine, tryptophan, and valine were also reduced on the 39% urea-N diet. In rumen epithelium, there was a reduction of the essential amino acids and an increase of the nonessential amino acids on the 76% urea-N diet.

scholarly journals Age-specific distribution of plasma amino acid concentrations in a healthy pediatric population

1997 ◽  
Vol 43 (12) ◽  
pp. 2397-2402 ◽  
Author(s):  
Nathalie Lepage ◽  
Nancy McDonald ◽  
Louis Dallaire ◽  
Marie Lambert
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Pediatric Population ◽  
Plasma Amino Acid ◽  
Steady Increase ◽  
Childhood And Adolescence ◽  
Healthy Children ◽  
Isoleucine Leucine ◽  
Specific Distribution ◽  
Amino Acid Concentrations

Abstract Reference values were determined for 23 plasma free amino acids from measurements done in 148 healthy children ranging from 0 to 18 years of age. Amino acid analysis was performed by ion-exchange chromatography. We propose a graphic form of presenting the age-specific distribution of plasma amino acid concentrations where the 10th, 50th, and 90th quantiles are illustrated. Although each amino acid possesses its own pattern of distribution, we can identify five different profiles. Nine amino acids (alanine, arginine, asparagine, methionine, ornithine, phenylalanine, proline, threonine, and tyrosine) demonstrate a decrease in their concentrations during the first year of life; their concentrations then tend to increase throughout childhood and adolescence. Nine others (cystine, glutamine, glycine, histidine, isoleucine, leucine, lysine, tryptophan, and valine) show a steady increase throughout infancy, childhood, and adolescence. Five amino acids (aspartic acid, citrulline, glutamic acid, serine, and taurine) do not follow these two common profiles. For the first time, quantile curves are produced to illustrate the age-dependent variation of amino acid concentrations from infancy to adulthood. This alternative way of presenting amino acid concentrations may facilitate the follow-up of patients with inborn errors of amino acid metabolism.

Effects of atropine on plasma amino acid profiles and on the synthesis of individual milk proteins in dairy cows fed with pasture

2003 ◽  
Vol 70 (4) ◽  
pp. 373-378 ◽  
Author(s):  
Martin J Auldist ◽  
Catherine M Menzies ◽  
Colin G Prosser
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Blood Plasma ◽  
Latin Square ◽  
Milk Proteins ◽  
Protein Composition ◽  
Essential Amino Acids ◽  
Plasma Amino Acid ◽  
Milk Components ◽  
In Blood Plasma

Effects of atropine on blood plasma amino acid profile and on the yields and concentration of milk components were investigated in 12 Friesian cows in early lactation. Cows were housed indoors and fed with cut pasture ad libitum. Each cow received four treatments over 12 d during a replicated 4×4 Latin square experiment. Treatments were: control (saline); low dose (L; 30 μg atropine/kg body weight (BW)); medium dose (M; 40 μg atropine/kg BW); and 2×L dose, 2 h apart (2×L). On each of four treatment days, cows were milked at about 7.00, after which treatments were administered by subcutaneous injection. Cows were milked again at 2 h, 6 h and 10 h after injection. Milk samples were collected at each milking. Immediately after the 2 h milking, blood samples were drawn from each cow and the second injection was given for the 2×L treatment. Atropine reduced hourly milk yield, and concentrations and hourly yields of total protein, casein, whey protein, α-casein, β-casein, κ-casein, β-lactoglobulin and α-lactalbumin, but by differing amounts. Milk concentrations of bovine serum albumin and immunoglobulin G were increased by atropine, and overall yields of these proteins were mostly unchanged. Atropine lowered concentrations of most, but not all, amino acids in blood plasma, with essential amino acids reduced more than non-essential amino acids. Concentrations of α-amino N in whole blood, and glucose and insulin in blood plasma, fell after atropine injection. There was no difference between the L and M doses of atropine, but the 2×L dose had greater effects on milk composition than the single doses. For yields of milk and milk components, the effect of the 2×L dose was also more persistent. The results highlight the differential synthesis of individual milk proteins, and suggest that atropine might be useful for evaluating the mechanisms regulating milk protein composition.

scholarly journals Biosynthesis of ‘essential’ amino acids by scleractinian corals

1997 ◽  
Vol 322 (1) ◽  
pp. 213-221 ◽  
Author(s):  
Lisa M. FITZGERALD ◽  
Alina M. SZMANT
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Reef Coral ◽  
Acid Synthesis ◽  
Essential Amino Acids ◽  
Acropora Cervicornis ◽  
Isoleucine Leucine ◽  
Amino Acid Synthesis ◽  
Protein Amino Acids

Animals rely on their diet for amino acids that they are incapable either of synthesizing or of synthesizing in sufficient quantities to meet metabolic needs. These are the so-called ‘essential amino acids’. This set of amino acids is similar among the vertebrates and many of the invertebrates. Previously, no information was available for amino acid synthesis by the most primitive invertebrates, the Cnidaria. The purpose of this study was to examine amino acid synthesis by representative cnidarians within the Order Scleractinia. Three species of zooxanthellate reef coral, Montastraea faveolata, Acropora cervicornis and Porites divaricata, and two species of non-zooxanthellate coral, Tubastrea coccinea and Astrangia poculata, were incubated with 14C-labelled glucose or with the 14C-labelled amino acids glutamic acid, lysine or valine. Radiolabel tracer was followed into protein amino acids. A total of 17 amino acids, including hydroxyproline, were distinguishable by the techniques used. Of these, only threonine was not found radiolabelled in any of the samples. We could not detect tryptophan or cysteine, nor distinguish between the amino acid pairs glutamic acid and glutamine, or aspartic acid and asparagine. Eight amino acids normally considered essential for animals were made by the five corals tested, although some of them were made only in small quantities. These eight amino acids are valine, isoleucine, leucine, tyrosine, phenylalanine histidine, methionine and lysine. The ability of cnidarians to synthesize these amino acids could be yet another indicator of a separate evolutionary history of the cnidarians from the rest of the Metazoa.

The uptake of amino acids by mouse cells (strain LS) during growth in batch culture and chemostat culture: the influence of cell growth rate

1967 ◽  
Vol 168 (1013) ◽  
pp. 421-438 ◽  
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Amino Acid ◽  
Cell Growth ◽  
Glutamic Acid ◽  
Batch Culture ◽  
Amino Acid Uptake ◽  
Essential Amino Acids ◽  
Growth Yields ◽  
Acid Uptake

The uptake of thirteen essential amino acids by mouse LS cells in suspension culture was determined by bacteriological assay methods. Chemostat continuous-flow cultures were used to determine the effect of different cell growth rates on the quantitative amino acid requirements for growth. The growth yields of the cells ( Y = g cell dry weight produced/g amino acid utilized) were calculated for each of the essential amino acids. A mixture of the non-essential amino acids, serine, alanine and glycine increased the cell yield from the essential amino acids. The growth yields from nearly all the essential amino acids in batch culture were increased when glutamic acid was substituted for the glutamine in the medium. The growth yields from the amino acids in batch culture were much less at the beginning than at the end of the culture. The highest efficiencies of conversion of amino acids to cell material were obtained by chemostat culture. When glutamic acid largely replaced the glutamine in the medium the conversion of amino acid nitrogen to cell nitrogen was 100 % efficient (that is, the theoretical yield was obtained) at the optimum growth rate (cell doubling time, 43 h). The maximum population density a given amino acid mixture will support can be calculated from the data. It is concluded that in several routinely used tissue culture media the cell growth is limited by the amino acid supply. In batch culture glutamine was wasted by (1) its spontaneous decomposition to pyrrolidone carboxylic acid and ammonia, and (2) its enzymic breakdown to glutamic acid and ammonia, but also glutamine was used less efficiently than glutamic acid. Study of the influence of cell growth rate on amino acid uptake rates per unit mass of cells indicated that a marked change in amino acid metabolism occurred at a specific growth rate of 0.4 day -1 (cell doubling time, 43 h). With decrease in specific growth rate below 0.4 day -1 there was a marked stimulation of amino acid uptake rate per cell and essential amino acids were consumed increasingly for functions other than synthesis of cell material.

USE OF GLUTAMIC ACID-U-C14 TO DETERMINE NUTRITIONALLY ESSENTIAL AMINO ACIDS FOR LARVAE OF THE BLOW FLY, PHORMIA REGINA

1960 ◽  
Vol 38 (11) ◽  
pp. 1229-1234 ◽  
Author(s):  
R. Kasting ◽  
A. J. McGinnis
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Essential Amino Acids ◽  
Phormia Regina ◽  
Blow Fly ◽  
Isoleucine Leucine ◽  
Low Level ◽  
Third Instar Larvae

The production of C14O2 by third-instar larvae of the blow fly, Phormia regina Meig., after it was injected with glutamic acid-U-C14, indicates that this substrate was metabolized under these conditions. However, the nutritionally essential amino acids lysine, phenylalanine, valine, isoleucine, leucine, and threonine, isolated from the injected larvae, contained little radioactivity. A low level of radioactivity in arginine, histidine, and methionine suggests that they were slowly synthesized. The nutritionally non-essential amino acids alanine, serine, aspartic acid, and proline contained large quantities of radioactivity; tyrosine and glycine were exceptions. These results, in agreement with earlier work that used glucose-U-C14, show that radioactivity data are useful for determining certain of the nutritionally essential amino acids.

USE OF GLUTAMIC ACID-U-C14 TO DETERMINE NUTRITIONALLY ESSENTIAL AMINO ACIDS FOR LARVAE OF THE BLOW FLY, PHORMIA REGINA

1960 ◽  
Vol 38 (1) ◽  
pp. 1229-1234 ◽  
Author(s):  
R. Kasting ◽  
A. J. McGinnis
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Essential Amino Acids ◽  
Phormia Regina ◽  
Blow Fly ◽  
Isoleucine Leucine ◽  
Low Level ◽  
Third Instar Larvae

The production of C14O2 by third-instar larvae of the blow fly, Phormia regina Meig., after it was injected with glutamic acid-U-C14, indicates that this substrate was metabolized under these conditions. However, the nutritionally essential amino acids lysine, phenylalanine, valine, isoleucine, leucine, and threonine, isolated from the injected larvae, contained little radioactivity. A low level of radioactivity in arginine, histidine, and methionine suggests that they were slowly synthesized. The nutritionally non-essential amino acids alanine, serine, aspartic acid, and proline contained large quantities of radioactivity; tyrosine and glycine were exceptions. These results, in agreement with earlier work that used glucose-U-C14, show that radioactivity data are useful for determining certain of the nutritionally essential amino acids.

scholarly journals Effect of zinc deficiency on appetite and plasma amino acid concentrations in the rat

1981 ◽  
Vol 45 (1) ◽  
pp. 127-136 ◽  
Author(s):  
J. C. Wallwork ◽  
G. J. Fosmire ◽  
H. H. Sandstead
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Eating Habits ◽  
Plasma Amino Acid ◽  
Zn Deficiency ◽  
Feeding Cycle ◽  
Cyclic Feeding ◽  
Amino Acid Concentrations ◽  
Cell Volumes ◽  
Deficient Group

1. Levels of zinc in liver and plasma of the Zn-depleted rats fluctuated with the feeding cycle and were significantly higher at the bottom than at the top of the cycle. As Zn deficiency became more severe fluctuations in plasma Zn diminished. Concentrations of Zn in liver, in contrast to levels in plasma and femur, were not markedly lowered by day 15.2. In contrast to udlib.-fed (AL) and overnight-fasted (OF) controls, some pair-fed (PF) controls had elevated levels of Zn in liver and plasma.3. Intakes of water and food were sigdicantly correlated in Zn-deficient rats. Packed cell volumes were significantly higher for Zn-depleted than for AL and PF rats.4. Food intakes and plasma glucose concentrations were related in AL, OF and PF control rats but not in Zn-deficient rats.5. At day 15 of Zn deficiency the order of total plasma amino acid concentrations in the groups of rats was AL > Zn-deficient > OF > PF. Many of the differences between the AL and OF groups for individual plasma amino acids also appeared in the Zn-deficient group at the top and bottom of the feeding cycle. Differences in individual amino acid conmntrations at the top and bottom of the feeding cycle tended to be opposite in the PF and the Zn-ddicient group. Levels of tyrosine and tryptophan in plasma were correlated (P ≶ 0.05) with the cyclic feeding pattern of the Zn-deficient group; however, the ratios tryptophan or tyrosine: sum of other large neutral amino acids did not correlate significantly with the eating habits of Zndeficient rats.

Effects of intramammary arterial infusion of essential amino acids in the lactating goat

1974 ◽  
Vol 41 (1) ◽  
pp. 101-109 ◽  
Author(s):  
J. L. Linzell ◽  
T. B. Mepham
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Milk Protein ◽  
Amino Acid Uptake ◽  
Essential Amino Acids ◽  
Acid Uptake ◽  
Lactating Goats ◽  
Arterial Concentration ◽  
Arterial Plasma ◽  
Amino Acid Concentrations

SummaryExperiments were performed on 3 lactating goats, in which mammary arterial plasma amino-acid concentrations were elevated by the infusion of a solution of essential amino-acids into the carotid artery supplying a transplanted mammary gland. In 2 experiments there were marked elevations in the arterial concentrations of most essential amino acids, but in one case only did this result in significantly increased uptake of amino acids by the gland, the arterio-venous difference being significantly correlated with arterial concentration for all except one amino acid. In the experiment in which increased amino-acid uptake was observed, infusion also resulted in a significantly increased milk yield and increased milk protein yield. The results are discussed in relation to data from other laboratories and lead to the suggestion that milk protein synthesis may be limited by the availability of either methionine or tryptophan.

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