scholarly journals Plasma amino acid concentrations in pregnant rats and in 21-day foetuses

1977 ◽  
Vol 166 (1) ◽  
pp. 49-55 ◽  
Author(s):  
A Palou ◽  
L Arola ◽  
M Alemany
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Plasma Amino Acid ◽  
Female Rats ◽  
Total Amino Acid ◽  
Acid Uptake ◽  
Pregnant Rats ◽  
Foetal Growth ◽  
Amino Acid Concentrations ◽  
Concentration Ratios

Plasma amino acid concentrations were determined in virgin female rats, in pregnant rats (12 and 21 days after impregnation) and in 21-day foetuses. The total amino acid concentration in plasma decreases significantly with pregnancy, being lower at 12 than at 21 days. Alanine, glutamine+glutamate and other ‘gluconeogenic’ amino acids decrease dramatically by mid-term, but regain their original concentrations at the end of the pregnancy. With most other amino acids, mainly the essential ones, the trend is towards lower concentrations which are maintained throughout pregnancy. These data agree with known nitrogen-conservation schemes in pregnancy and with the important demands on amino acids provoked by foetal growth. In the 21-day foetuses, concentrations of individual amino acids are considerably higher than in their mothers, with high plasma foetal/maternal concentration ratios, especially for lysine, phenylalanine and hydroxy-proline, suggesting active protein biosynthesis and turnover. All other amino acids also have high concentration ratios, presumably owing to their requirement by the foetuses for growth. Alanine, glutamine+glutamate, asparagine+aspartate, glycine, serine and threonine form a lower proportion of the total amino acids in foetuses than in the virgin controls or pregnant rats, probably owing to their role primarily in energy metabolism in the adults. The results indicate that at this phase of foetal growth, the placental amino acid uptake is considerable and seems to be higher than immediately before birth.

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.

Amino acid metabolism in leg muscle after an endotoxin injection in healthy volunteers

2005 ◽  
Vol 288 (2) ◽  
pp. E360-E364 ◽  
Author(s):  
Rokhsareh F. Vesali ◽  
Maria Klaude ◽  
Olav Rooyackers ◽  
Jan Wernerman
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Amino Acid ◽  
Healthy Volunteers ◽  
Initial Phase ◽  
Plasma Amino Acid ◽  
Human Model ◽  
Endotoxin Administration ◽  
Leg Muscle ◽  
Amino Acid Concentrations

Decreased plasma amino acid concentrations and increased net release of amino acids from skeletal muscle, especially for glutamine, are common features in critically ill patients. A low dose of endotoxin administered to healthy volunteers was used as a human model for the initial phase of sepsis to study the early metabolic response to sepsis. Six healthy male volunteers were studied in the postabsorptive state. Blood samples from the forearm artery and femoral vein were taken during 4 h before and 4 h after an intravenous endotoxin injection (4 ng/kg body wt). In addition, muscle biopsies from the leg muscle were taken. Plasma concentration of the total sum of amino acids decreased by 19% ( P = 0.001) and of glutamine by 25% ( P = 0.004) the 3rd h after endotoxin administration. At the same time, muscle concentrations of the sum of amino acids and glutamine decreased by 11% ( P = 0.05) and 9% ( P = 0.09), respectively. In parallel, the efflux from the leg increased by 35% ( P = 0.004) for the total sum of amino acids and by 43% ( P = 0.05) for glutamine. In conclusion, intravenous endotoxin administration to healthy volunteers, used as a model for the initial phase of sepsis, resulted in a decrease in plasma amino acid concentrations. At the same time, amino acid concentrations in muscle tissue decreased, whereas the efflux of amino acids from leg skeletal muscle increased.

scholarly journals Comparison of the effects of a high- and normal-casein breakfast on satiety, ‘satiety’ hormones, plasma amino acids and subsequent energy intake

2008 ◽  
Vol 101 (2) ◽  
pp. 295-303 ◽  
Author(s):  
Margriet A. B. Veldhorst ◽  
Arie G. Nieuwenhuizen ◽  
Ananda Hochstenbach-Waelen ◽  
Klaas R. Westerterp ◽  
Marielle P. K. J. Engelen ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Energy Intake ◽  
Plasma Amino Acid ◽  
Plasma Amino Acids ◽  
Casein Protein ◽  
Ad Libitum ◽  
Glucagon Like Peptide 1 ◽  
Branched Chain ◽  
Amino Acid Concentrations

The present study compared the effects of a high- and normal-casein-protein breakfast on satiety, ‘satiety’ hormones, plasma amino acid responses and subsequent energy intake. Twenty-five healthy subjects (BMI 23·9 (sem 0·3) kg/m2; age 22 (sem 1) years) received a subject-specific standardised breakfast (20 % of daily energy requirements): a custard with casein as the single protein source with either 10, 55 and 35 (normal-casein breakfast) or 25, 55 and 20 (high-casein breakfast) % of energy (En%) from protein, carbohydrate and fat respectively in a randomised, single-blind design. Appetite profile (visual analogue scale; VAS), plasma glucose, insulin, glucagon-like peptide 1, ghrelin and amino acid concentrations were determined for 4 h; here the sensitive moment in time for lunch was determined. Subjects came for a second set of experiments and received the same custards for breakfast, and an ad libitum lunch was offered at 180 min after breakfast; energy intake was assessed. There were increased scores of fullness and satiety after the 25 En% casein-custard compared with the 10 En% casein-custard, particularly at 180 min (26 (sem 4) v. 11 (sem 5) mm VAS; P < 0·01) and 240 min (13 (sem 5) v. − 1 (sem 5) mm VAS; P < 0·01). This coincided with prolonged elevated plasma amino acid concentrations; total amino acids and branched-chain amino acids were higher after the 25 En% casein-custard compared with the 10 En% casein-custard at 180 and 240 min (P < 0·001). There was no difference in energy intake (3080 (sem 229) v. 3133 (sem 226) kJ for 25 En% and 10 En% respectively; NS) from the ad libitum lunch. In conclusion, a breakfast with 25 % of energy from casein is rated as being more satiating than a breakfast with 10 % of energy from casein at 3 and 4 h after breakfast, coinciding with prolonged elevated concentrations of plasma amino acids, but does not reduce subsequent energy intake.

scholarly journals Amino acids in Arctic aerosols

2012 ◽  
Vol 12 (7) ◽  
pp. 17367-17396 ◽  
Author(s):  
E. Scalabrin ◽  
R. Zangrando ◽  
E. Barbaro ◽  
N. M. Kehrwald ◽  
J. Gabrieli ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Water Cycle ◽  
Amino Acid Content ◽  
Boreal Summer ◽  
Total Amino Acid ◽  
Radiation Balance ◽  
Polar Regions ◽  
Wide Range ◽  
Amino Acid Concentrations

Abstract. Amino acids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of amino acid reactivities suggest that amino acids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess amino acid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of amino acid compounds in the global atmosphere, we determined free amino acids (FAAs) in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS) to analyze 20 amino acids to quantify compounds at fmol m−3 levels. Mean total FAA concentration was 1070 fmol m−3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45–60% of the total amino acid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m−3. The higher amino acid concentrations were present in the ultrafine aerosol fraction (<0.49 μm) and accounted for the majority of the total amino acid content. Local marine sources dominate the boreal summer amino acid concentrations, with the exception of the regional input from Icelandic volcanics.

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.

Valine entry into rat brain after diet-induced changes in plasma amino acids

1987 ◽  
Vol 252 (1) ◽  
pp. R78-R84
Author(s):  
J. K. Tews ◽  
J. Greenwood ◽  
O. E. Pratt ◽  
A. E. Harper
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Content ◽  
Protein Intake ◽  
Amino Acid Uptake ◽  
Plasma Amino Acid ◽  
Acid Uptake ◽  
Induced Changes ◽  
The Brain

Passage of amino acids across the blood-brain barrier is assumed to be modified by amino acid composition of the blood. To gain a better understanding of the effects of protein intake on brain amino acid uptake, we examined associations among diet, plasma amino acid patterns, and the rate of entry of valine into the brain. Rats were fed (8 h/day for 7–10 days) diets containing 6, 18, or 50% casein before receiving one meal of a diet containing 0, 6, 18, or 50% casein. After 4–7 h, they were anesthetized and infused intravenously with [14C]valine for 5 min before plasma and brain samples were taken for determination of radioactivity and content of individual amino acids. As protein content of the meal was increased from 0 to 50% casein, plasma and brain concentrations of valine and most other large neutral amino acids (LNAA) increased severalfold; also the ratio of [14C]valine in brain to that in plasma decreased by greater than 50%, and the rate of valine entry into the brain increased 3.5-fold. The increase in valine flux slowed as plasma levels of LNAA, competitors for valine transport, increased. The results were far more dependent on protein content of the final meal than on that of the adaptation diet; thus changes in protein intake, as reflected in altered plasma amino acid patterns, markedly altered valine entry into the brain.

scholarly journals Amino acids in Arctic aerosols

2012 ◽  
Vol 12 (21) ◽  
pp. 10453-10463 ◽  
Author(s):  
E. Scalabrin ◽  
R. Zangrando ◽  
E. Barbaro ◽  
N. M. Kehrwald ◽  
J. Gabrieli ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Content ◽  
Boreal Summer ◽  
Total Amino Acid ◽  
Radiation Balance ◽  
Polar Regions ◽  
Volcanic Emissions ◽  
Wide Range ◽  
Amino Acid Concentrations

Abstract. Amino acids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of amino acid reactivities suggest that amino acids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess amino acid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of amino acid compounds in the global atmosphere, we determined free amino acids (FAAs) in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS) to analyze 20 amino acids and quantify compounds at fmol m−3 levels. Mean total FAA concentration was 1070 fmol m−3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45–60% of the total amino acid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m−3. The higher amino acid concentrations were present in the ultrafine aerosol fraction (< 0.49 μm) and accounted for the majority of the total amino acid content. Local marine sources dominate the boreal summer amino acid concentrations, with the exception of the regional input from Icelandic volcanic emissions.

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