scholarly journals The importance of transmethylation reactions to methionine metabolism in sheep: effects of supplementation with creatine and choline

1996 ◽  
Vol 75 (1) ◽  
pp. 47-56 ◽  
Author(s):  
G. E. Lobley ◽  
A. Connell ◽  
D. Revell
Keyword(s):  
Amino Acid ◽  
Venous Blood ◽  
Amino Acid Mixture ◽  
Intradermal Injection ◽  
Acid Mixture ◽  
Label Pattern ◽  
Similar Data ◽  
Hepatic Venous Blood ◽  
Significant Depression ◽  
Hepatic Portal

The influence of administering the methylated products choline and creatine on methionine irreversible loss rate (ILR) and recycling from homocysteine has been investigated in sheep fed close to energy and N equilibrium. Two methods to estimate methionine recycling were compared. The first involved & [U-13C& ]methionine infused as part of a labelled amino acid mixture obtained from hydrolysed algal protein. In this approach the isotope dilution of methionine with all five C atoms labelled (m+5) will represent the ILR which does not recycle through homocysteine, while that which includes molecules with C-l–C-4 labelled will allow for loss of the labelled methyl (5)-C atom and replacement by an unlabelled moiety in the remethylation of homocysteine. The second method involved a combined infusion of [l-13C]- & [S-methyl-2H3& rsqb;methionine. These two approaches gave similar data for methionine ILR which does not include label recycled to the amino acid from homocysteine but differed for recycled methionine fluxes. Consequently the two procedures differed in the calculated extent of homocysteine methylation under control conditions (6 v. 28). These extents of remethylation are within the range observed for the fed human subject, despite the fact that fewer dietary methyl groups are available for the ruminant. Using combined data from the infwions, significant depression of methionine recycling occurred in blood (P <0·05), with a similar trendfor plasma (P = 0·077), when choline plus creatine were infused. Wool growth, assessed by intradermal injection of [35S]cysteine, was not altered by supplementation with the methylated products. From changes in the label pattern of free methionine in aortal, hepatic portal and hepatic venous blood during U-13C-labelled algal hydrolysate infusion, the major sites of homocysteine remethylation appear to be the portal-drained viscera and the liver. This was confirmed by analysis of free methionine enrichments in various tissues following dual infusion of & [1J3C& ]- and & [S-methyl-2H3methionine, with the greatest activities occurring in rumen, jejunum and liver. Of the non-splanchnic tissues examined, only kidney exhibited substantial methionine cycling; none was detected in muscle, heart, lung and skin. The implications of methyl group provision under net prduction conditions are discussed.

15N enrichments of casein and plasma protein amino acids in cows ingesting 15N-labelled ammonium sulphate

1997 ◽  
Vol 64 (3) ◽  
pp. 367-376
Author(s):  
FLORENCE CASSERON ◽  
GUIDO RYCHEN ◽  
XIMO RUBERT-ALEMAN ◽  
GERARD JEAN MARTIN ◽  
FRANÇOIS LAURENT
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Plasma Protein ◽  
Plasma Proteins ◽  
Venous Blood ◽  
Isotope Ratio Mass Spectrometry ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Liver Protein ◽  
Lactating Cows

The aim of this work was to determine by ion-exchange liquid chromatography and isotope ratio mass spectrometry the specific 15N enrichment of amino acids in casein and plasma proteins in cows receiving three successive daily oral doses (300, 150 and 150 g) of (15NH4)2SO4 (10 atom per cent isotopic enrichment) and to examine the 15N enrichments obtained with regard to nitrogen transport and metabolism in the lactating cow. To investigate the 15N distribution in amino acids in casein and in plasma proteins, samples of 15N-labelled casein and plasma proteins were extracted either from a pool of several milkings (36–96 h after starting to administer the tracer) or from pooled venous blood (removed on the fourth day after the start of administration) from the four lactating cows. 15N enrichments of the proteins studied, expressed as atoms percent excess, were 0·2509 for casein and 0·0577 for plasma protein. Chromatographic fractionation of the amino acid mixture (protein hydrolysates) resulted in nine groups containing between one and four amino acids: Asp, Ser and Thr; Glu; Pro; Gly, Ala, Val and Met; Ileu and Leu; Tyr; Phe; His and Lys; and Arg. High 15N incorporation was demonstrated in all individual or groups of amino acids studied. In both proteins, Glu appeared to be the most enriched amino acid, Phe and Arg the least enriched. Most aliphatic molecules with a single amino group were highly enriched. The much lower (3·5–7·7-fold) enrichments in plasma protein compared with casein suggest considerable intracellular dilution at the site of liver protein synthesis. Finally, the amino acid separation methods are discussed and suggestions for improving them considered.

An open-label, single-center pilot study to test the effects of an amino acid mixture in older patients admitted to internal medicine wards

Nutrition ◽  
2020 ◽  
Vol 69 ◽  
pp. 110588 ◽  
Author(s):  
Francesco Bellanti ◽  
Aurelio Lo Buglio ◽  
Elena Di Stasio ◽  
Giorgia di Bello ◽  
Rosanna Tamborra ◽  
...  
Keyword(s):  
Internal Medicine ◽  
Amino Acid ◽  
Pilot Study ◽  
Older Patients ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Single Center ◽  
Open Label ◽  
Internal Medicine Wards

Choosing A Balanced Amino Acid Mixture

1970 ◽  
Vol 100 (3) ◽  
pp. 380-380 ◽  
Author(s):  
Hans Fisher
Keyword(s):  
Amino Acid ◽  
Amino Acid Mixture ◽  
Acid Mixture

scholarly journals Effect of co-ingestion of amino acids with rice on glycaemic and insulinaemic response

2015 ◽  
Vol 114 (11) ◽  
pp. 1845-1851 ◽  
Author(s):  
Yean Yean Soong ◽  
Joseph Lim ◽  
Lijuan Sun ◽  
Christiani Jeyakumar Henry
Keyword(s):  
Amino Acids ◽  
Blood Glucose ◽  
Amino Acid ◽  
Glycaemic Index ◽  
Amino Acid Mixture ◽  
Postprandial Blood Glucose ◽  
Acid Mixture ◽  
White Rice ◽  
Amino Acid Mixtures

AbstractConsumption of high glycaemic index (GI) and glycaemic response (GR) food such as white rice has been implicated in the development of type 2 diabetes. Previous studies have reported the ability of individual amino acids to reduce GR of carbohydrate-rich foods. Because of the bitter flavour of amino acids, they have rarely been used to reduce GR. We now report the use of a palatable, preformed amino acid mixture in the form of essence of chicken. In all, sixteen healthy male Chinese were served 68 or 136 ml amino acid mixture together with rice, or 15 or 30 min before consumption of white rice. Postprandial blood glucose and plasma insulin concentrations were measured at fasting and every 15 min after consumption of the meal until 60 min after the consumption of the white rice. Subsequent blood samples were taken at 30-min intervals until 210 min. The co-ingestion of 68 ml of amino acid mixture with white rice produced the best results in reducing the peak blood glucose and GR of white rice without increasing the insulinaemic response. It is postulated that amino acid mixtures prime β-cell insulin secretion and peripheral tissue uptake of glucose. The use of ready-to-drink amino acid mixtures may be a useful strategy for lowering the high-GI rice diets consumed in Asia.

Olfactory Conditioning by Association with Histidine-Free or Balanced Amino Acid Loads in Rats†

1973 ◽  
Vol 25 (3) ◽  
pp. 354-359 ◽  
Author(s):  
P. C. Simson ◽  
D. A. Booth
Keyword(s):  
Amino Acid ◽  
Food Intake ◽  
Amino Acid Mixture ◽  
Conditioned Aversion ◽  
Acid Mixture ◽  
Olfactory Conditioning ◽  
Conditioned Preference ◽  
Gastric Intubation ◽  
Protein Free Diet

An histidine-devoid but otherwise balanced amino acid mixture depressed food intake from 2 hr after its gastric intubation. It induced conditioned aversion to an odour incorporated in a protein-free diet presented for 6 h following intubation. In other rats, a balanced amino acid mixture established conditioned preference for odour presented in the same diet for 6 h following intubation. The degree of preference was considerably less than the degree of aversion.

Liver extract and its free amino acids equally stimulate gastric acid secretion

1980 ◽  
Vol 239 (6) ◽  
pp. G493-G496 ◽  
Author(s):  
E. J. Feldman ◽  
M. I. Grossman
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Secretion ◽  
Gastric Acid Secretion ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Liver Extract ◽  
Amino Acid Mixture ◽  
Acid Mixture

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.

scholarly journals THE EFFECT OF dl-METHIONINE, l-CYSTINE, AND dl-ISOLEUCINE ON THE UTILIZATION OF PARENTERALLY ADMINISTERED DOG HEMOGLOBIN

1947 ◽  
Vol 85 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Leon L. Miller ◽  
Eric L. Alling
Keyword(s):  
Amino Acid ◽  
Developmental Stages ◽  
Peripheral Circulation ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Absorption Bands ◽  
Suggested Approach ◽  
Dog Plasma ◽  
Veronal Buffer ◽  
Definition Of

1. Further observations on the utilization of parenterally administered dog hemoglobin show that oral supplements of dl-methionine and l-cystine improve the efficiency of utilization of hemoglobin N, while a fed supplement of dl-isoleucine alone is without effect. 2. When N-isoleucine is added to a fed supplement of methionine or methionine and cystine, the utilization of parenterally given hemoglobin N is even better than with the sulfur-containing amino acids alone. 3. A suggested approach to the problem of designing the quantitatively "ideal" amino acid mixture lies in the definition of what may be called total organism-amino acid patterns of rat, dog, man, etc. These may vary considerably not only at different developmental stages in a given species, but also certainly from one species to another. 4. Further attempts to detect globin in the peripheral circulation have pointed to the need for a highly specific procedure such as that an immunologic method may offer. 5. Reduced hemin in dog plasma migrates with α1-globulin and albumin in veronal buffer at pH 8.5 and the colored zones give strong hemochromogen absorption bands.

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