1
|
Breborowicz A, Witowski J, Knapowski J, Oreopoulos GD, Balaskas EV, Oreopoulos DG. In Vitro Cytotoxicity of Amino Acids and Their Glycyl-Dipeptide Forms to Human Peritoneal Mesothelial Cells. Perit Dial Int 2020. [DOI: 10.1177/089686089401400219] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Andrzej Breborowicz
- Department of Pathophysiology Medical School Poznan Poznan, Poland; Toronto Western Hospital University of Toronto Toronto, Canada
| | - Janusz Witowski
- Department of Pathophysiology Medical School Poznan Poznan, Poland; Toronto Western Hospital University of Toronto Toronto, Canada
| | - Jan Knapowski
- Department of Pathophysiology Medical School Poznan Poznan, Poland; Toronto Western Hospital University of Toronto Toronto, Canada
| | - George D. Oreopoulos
- Department of Pathophysiology Medical School Poznan Poznan, Poland; Toronto Western Hospital University of Toronto Toronto, Canada
| | - Elias V. Balaskas
- Department of Pathophysiology Medical School Poznan Poznan, Poland; Toronto Western Hospital University of Toronto Toronto, Canada
| | - Dimitrios G. Oreopoulos
- Department of Pathophysiology Medical School Poznan Poznan, Poland; Toronto Western Hospital University of Toronto Toronto, Canada
| |
Collapse
|
2
|
Fischer A, Bommarius AS, Drauz K, Wandrey C. A Novel Approach to Enzymatic Peptide Synthesis Using Highly Solubilizing Nα-Protecting Groups of Amino Acids. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/10242429408998213] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Andreas Fischer
- Institute of Biotechnology, Research Center Jülich, P.O. Box 1913, D-52425, Jülich, Germany
| | - Andreas S. Bommarius
- Degussa AG, Organic and Biological Chemistry R & D, P.O. Box 1345, D-63403, Hanau, Germany
| | - Karlheinz Drauz
- Degussa AG, Organic and Biological Chemistry R & D, P.O. Box 1345, D-63403, Hanau, Germany
| | - Christian Wandrey
- Institute of Biotechnology, Research Center Jülich, P.O. Box 1913, D-52425, Jülich, Germany
| |
Collapse
|
3
|
Mabjeesh SJ, Gal-Garber O, Milgram J, Feuermann Y, Cohen-Zinder M, Shamay A. Aminopeptidase N Gene Expression and Abundance in Caprine Mammary Gland is Influenced by Circulating Plasma Peptide. J Dairy Sci 2005; 88:2055-64. [PMID: 15905436 DOI: 10.3168/jds.s0022-0302(05)72882-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This study examined the localization and the effect of circulating peptides on the expression of aminopeptidase N (EC 3.4.11.2) in caprine mammary gland. Four lactating goats in mid to late lactation were used in a crossover design and were subjected to 2 dietary treatments. Abomasal infusion of casein hydrolysate was used to increase the concentration of peptide-bound amino acid in the circulation. Samples of mammary gland tissue from each goat were taken by biopsy at the end of each treatment period to measure gene and protein expression of aminopeptidase N in the tissue. There were no measurable effects on feed intake and milk production for any of the treatments. Western blot analysis showed that aminopeptidase N is located on the basolateral side of parenchymal cells and not on the apical membranes. Abomasal infusion of casein hydrolysate caused a marked change in the profile of arterial blood free amino acids and peptide-bound amino acids smaller than 1500 Da. Abundance of aminopeptidase N mRNA and protein increased by 51 and 58%, respectively, in casein hydrolysate-infused goats compared with the control treatment. It was concluded that aminopeptidase N is one candidate actively involved in the mammary gland to support protein synthesis and milk production. In accordance with the nutritional conditions in the current experiment, it is suggested that aminopeptidase N expression is partly controlled by the metabolic requirements of the gland and postabsorptive forms of amino acids in the circulation.
Collapse
Affiliation(s)
- S J Mabjeesh
- Department of Animal Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, PO Box 12, Rehovot, Israel.
| | | | | | | | | | | |
Collapse
|
4
|
Zhang EY, Knipp GT, Ekins S, Swaan PW. Structural biology and function of solute transporters: implications for identifying and designing substrates. Drug Metab Rev 2002; 34:709-50. [PMID: 12487148 DOI: 10.1081/dmr-120015692] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Solute carrier (SLC) proteins have critical physiological roles in nutrient transport and may be utilized as a mechanism to increase drug absorption. However, we have little understanding of these proteins at the molecular level due to the absence of high-resolution crystal structures. Numerous efforts have been made in characterizing the peptide transporter (PepT1) and the apical sodium dependent bile acid transporter (ASBT) that are important for both their native transporter function as well as targets to increase absorption and act as therapeutic targets. In vitro and computational approaches have been applied to gain some insight into these transporters with some success. This represents an opportunity for optimizing molecules as substrates for the solute transporters and providing a further screening system for drug discovery. Clearly the future growth in knowledge of SLC function will be led by integrated in vitro and in silico approaches.
Collapse
Affiliation(s)
- Eric Y Zhang
- Division of Pharmaceutics, The Ohio State University, 500 West 12th Avenue, Columbus, OH 43210-1291, USA
| | | | | | | |
Collapse
|
5
|
Abstract
Transport proteins have critical physiological roles in nutrient transport and may be utilized as a mechanism to increase drug absorption. However, we have little understanding of these proteins at the molecular level due to the absence of high-resolution crystal structures. Numerous efforts have been made to characterize the P-glycoprotein efflux pump, the peptide transporter (PepT1) and the apical sodium-dependent transporter (ASBT) which are important not only for their native transporter function but also as drug targets to increase absorption and bioactivity. In vitro and computational approaches have been applied to gain some insight into these transporters with some success. This represents an opportunity for optimizing molecules as substrates for the solute transporters and providing a further screening system for drug discovery. Clearly the future growth in knowledge of transporter function will be led by integrated in vitro and in silico approaches.
Collapse
Affiliation(s)
- Eric Y Zhang
- Division of Pharmaceutics, The Ohio State University, 500 West 12th Avenue, Columbus, OH 43210-1291, USA
| | | | | | | | | |
Collapse
|
6
|
Coudray-Lucas C, Lasnier E, Renaud F, Ziegler F, Settembre P, Cynober LA, Ekindjian OG. Is alpha-ketoisocaproyl-glutamine a suitable glutamine precursor to sustain fibroblast growth? Clin Nutr 1999; 18:29-33. [PMID: 10459079 DOI: 10.1016/s0261-5614(99)80046-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Glutamine is considered an essential nutrient for cellular growth. AIM To test the suitability of alpha-ketoisocaproyl-Gln (Kic-Gln) as a new glutamine (Gln) precursor to sustain human fibroblast growth. METHODS [3H] thymidine uptake into cellular DNA of human fibroblasts. Extracellular and intracellular amino acid patterns were determined with peptides and acylated compounds. RESULTS L-alanyl-L-glutamine (used here as a recognized Gln precursor) promoted DNA synthesis, while N-acetyl-L-glutamine (used here as a negative control since it is known to be a poor Gln precursor) and alpha-ketoisocaproyl-glutamine had no effect. Alanyl-glutamine progressively gave rise to free glutamine in the growth medium. In contrast, glutamine supplied in acylated form was poorly available and did not appear in free form in the medium. In addition, only alanyl-glutamine increased intracellular glutamine and glutamate levels. In contrast, Kic-Gln was able to sustain net protein synthesis as judged by total protein content and reduced intracellular levels of most essential amino acids. CONCLUSION Kic-Gln appears to be a poor extra-cellular precursor of Gln to sustain cell growth.
Collapse
Affiliation(s)
- C Coudray-Lucas
- Inflammation and Cell Biology Laboratory, University Paris XI, Chatenay, France
| | | | | | | | | | | | | |
Collapse
|
7
|
Shennan DB, Calvert DT, Backwell FR, Boyd CA. Peptide aminonitrogen transport by the lactating rat mammary gland. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1373:252-60. [PMID: 9733976 DOI: 10.1016/s0005-2736(98)00107-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Recent studies have shown that the lactating mammary gland is able to utilize plasma-derived dipeptides for milk protein synthesis. However, it was not clear whether the peptides were hydrolysed followed by uptake of the constituent amino acids or were taken up intact. In view of this, we have designed experiments to investigate (a) whether the lactating rat mammary gland is capable of transporting hydrolysis-resistant dipeptides and (b) whether or not mammary cells are able to hydrolyse peptides, including glutathione, extracellularly. The uptake of the hydrolysis-resistant dipeptides D-[3H]Phe-L-Gln and D-[3H]Phe-L-Glu by the perfused rat mammary gland was low. Concomitant addition of L-Leu-L-Ala (50 mM) had no effect on the clearance of either labelled dipeptide suggesting that the small, albeit significant, uptake of the dipeptides is not via a high affinity peptide transporter (PepT1/PepT2). All anionic dipeptides tested (L-Glu-L-Ala, L-Asp-L-Ala, L-Ala-L-Asp, L-Asp-Gly, Gly-L-Asp and Gly-L-Glu) with the exception of D-Phe-L-Glu were able to trans-accelerate the efflux of labelled D-aspartate from preloaded rat mammary tissue (explants and perfused mammary gland). It appears that these peptides were being hydrolysed extracellularly followed by the uptake of free anionic amino acids via the mammary tissue high affinity, Na+-dependent anionic amino acid carrier operating in the exchange mode. Glutathione was able to trans-accelerate D-aspartate efflux from lactating rat mammary tissue in a fashion which was sensitive to the peptidase inhibitor acivicin. This suggests that gamma-glutamyltranspeptidase hydrolyses glutathione to produce L-glutamate which is subsequently transported via the high-affinity anionic amino acid carrier. Hydrolysis of peptides followed by uptake of the constituent amino acids may provide an important source of amino acids for milk protein synthesis.
Collapse
|
8
|
Affiliation(s)
- P Fürst
- University of Hohenheim, Institute for Biological Chemistry and Nutrition, D-70593 Stuttgart, Germany
| |
Collapse
|
9
|
Pan Y, Bender PK, Akers RM, Webb KE. One or more serum factors promote peptide utilization in cultured animal cells. J Nutr 1998; 128:744-50. [PMID: 9521638 DOI: 10.1093/jn/128.4.744] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We have shown previously that MACT-T and C2C12 cells utilize methionine-containing di- to octapeptides as methionine sources for protein accretion and cell proliferation in the presence of 60 mL/L desalted fetal bovine serum. In this study, serum factors that may regulate the use of peptides as amino acid sources in C2C12 and MAC-T cells were examined. The basal media contained methionine-free Dulbecco's modified Eagle's medium supplemented with 4.0 mL/L bovine serum lipids, 10 mL/L chemically defined lipid concentrate, bovine insulin (1 mg/L), 30 mL/L low protein serum replacement (LPSR-1) or 60 mL/L desalted animal serum. Treatment media included basal media supplemented with no methionine, L-methionine, or one of the methionine-containing peptides. L-Methionine promoted protein and DNA accretion (P < 0.05) in the presence of desalted animal sera, insulin or LPSR-1. Methionine-containing peptides also promoted protein and DNA accretion (P < 0.05) in the presence of desalted animal sera or LPSR-1, but not with insulin, except methionylleucine. In a cell-free medium, fetal bovine serum hydrolyzed peptides to varying degrees. We conclude that animal sera contain one or more factors that regulate utilization of peptides as amino acid sources for C2C12 and MAC-T cells.
Collapse
Affiliation(s)
- Y Pan
- Departments of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0306, USA
| | | | | | | |
Collapse
|
10
|
Smolle KH, Kaufmann P, Fleck S, Lueger A, Mausser G, Pölz W, Kleinberger G, Krejs GJ. Influence of a novel amino acid solution (enriched with the dipeptide glycyl-tyrosine) on plasma amino acid concentration of patients with acute renal failure. Clin Nutr 1997; 16:239-46. [PMID: 16844602 DOI: 10.1016/s0261-5614(97)80035-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/1996] [Accepted: 01/24/1997] [Indexed: 10/26/2022]
Abstract
In this randomized, double-blind controlled study we compared the effect of parenteralnutrition with two different amino acid solutions on the plasma concentration of amino acids in 27 patients with acute renal failure. Fourteen patients received the new dipeptide-containing (glycyl-tyrosine) amino acid solution (AADI) in combination with glucose (60%) and fat (10%) as an 'all-in-one' solution over 120 h continuously via a central venous catheter. In the control group (AAST), parenteral nutrition with a standard amino acid solution in isonitrogenous and isocaloric form (0.7 g amino acids/kg BW/day and 25 kcal/kg BW/day) was administered to 13 patients over the same period of time. The administration of the dipeptide-containing amino acid solution caused a return to within the normal range of most of the amino acid concentrations which were decreased at the onset. A significant difference could be found between the AADI and AAST group for the achieved plasma concentrations of threonine (P < 0.01), phenylalanine (P<0.05), isoleucine (P<0.05), tryptophan (P<0.01) and ornithine (P<0.05), The phenylalanine/tyrosine ratio, did not change in the AADI group, while a marked increase was observed in the AAST group. (152.7 +/- 23.5 - 159.8 +/- 37.6 vs 172.6 +/- 24.6 - 310.6 +/- 136.7, respectively). The plasma concentration of glycyl-tyrosine was at the limit of detectability indicating rapid hydrolysis of the dipeptide in acute renal failure. These data suggest that the new dipeptide-containing amino acid solution offers a clear advantage over a standard amino acid formulation in correcting the amino acid imbalances in plasma of patients with ARF and is able to maintain normal tyrosine concentrations and phenylalanine/tyrosine ratio.
Collapse
Affiliation(s)
- K H Smolle
- Department of Internal Medicine, Karl Franzens University, Graz, Austria
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Abstract
Glutamine is a conditional indispensable amino acid during stress. However, limited solubility and instability of glutamine prevent its addition to presently available nutritional preparations. To overcome these drawbacks, we propose the dipeptide concept by which stable and highly soluble synthetic glutamine containing dipeptides are used. The synthetic dipeptides fulfill all chemical/physical properties to be considered as parenteral substrates. Numerous experimental studies show rapid clearance of parenteral supplied glutamine containing dipeptides without accumulation in tissues; the loss via the urine being inconsequential. Differences related to the dipeptide structure are not observed. There is overwhelming evidence existent that a nutritional support with supplemental glutamine dipeptide positively influences nitrogen excretion, immune status, gut integrity, morbidity, rehabilitation and outcome. Consequently, omission of glutamine from conventional TPN and its subsequent administration should be considered as a replacement of a deficiency rather than a supplementation. It might thus be conceivable that the beneficial effects observed with glutamine nutrition are simply a correction of disadvantages produced by an inadequacy of conventional amino acid solutions. The availability of stable glutamine containing preparations will certainly facilitate an adequate amino acid nutrition in routine clinical setting during episodes of stress and malnutrition.
Collapse
Affiliation(s)
- P Fürst
- Institute for Biological Chemistry and Nutrition, University of Hohenheim, Stuttgart, Germany
| | | | | |
Collapse
|
12
|
Herzog B, Frey B, Pogan K, Stehle P, Fürst P. In vitro peptidase activity of rat mucosa cell fractions against glutamine-containing dipeptides. J Nutr Biochem 1996. [DOI: 10.1016/0955-2863(95)00195-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
13
|
Liu W, Liang R, Ramamoorthy S, Fei YJ, Ganapathy ME, Hediger MA, Ganapathy V, Leibach FH. Molecular cloning of PEPT 2, a new member of the H+/peptide cotransporter family, from human kidney. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1235:461-6. [PMID: 7756356 DOI: 10.1016/0005-2736(95)80036-f] [Citation(s) in RCA: 204] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Mammalian kidney is known to express a transport system specific for small peptides and pharmacologically active aminocephalosporins. This system is energized by a transmembrane electrochemical H+ gradient. Recently, a H(+)-coupled peptide transporter has been cloned from rabbit and human intestine (Fei et al. (1994) Nature 368, 563-566; Liang et al., J. Biol. Chem., in press). Functional studies have established that the renal peptide transport system is similar but not identical to its intestinal counterpart. Therefore, in an attempt to isolate the renal H+/peptide cotransporter cDNA, we screened a human kidney cDNA library with a probe derived from the rabbit intestinal H+/peptide cotransporter cDNA. This has resulted in the isolation of a positive clone with a 2190 bp long open reading frame. The predicted protein consists of 729 amino acids. Hydropathy analysis of the amino acid sequence indicates the presence of twelve putative transmembrane domains. The primary structure of this protein exhibits 50% identity and 70% similarity to the human intestinal H+/peptide cotransporter. Functional expression of the kidney cDNA in HeLa cells results in the induction of a H(+)-coupled transport system specific for small peptides and aminocephalosporins. Reverse transcription-coupled polymerase chain reaction demonstrates that the cloned transporter is expressed in human kidney but not in human intestine. This transporter, henceforth called PEPT 2, represents a new member in the growing family of H(+)-coupled transport systems in the mammalian plasma membrane.
Collapse
Affiliation(s)
- W Liu
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta 30912, USA
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Backwell FR. Peptide utilization by tissues: current status and applications of stable isotope procedures. Proc Nutr Soc 1994; 53:457-64. [PMID: 7886046 DOI: 10.1079/pns19940056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
|
15
|
Kee AJ, Smith RC, Gross AS, Madsen DC, Rowe B. The effect of dipeptide structure on dipeptide and amino acid clearance in rats. Metabolism 1994; 43:1373-8. [PMID: 7968592 DOI: 10.1016/0026-0495(94)90030-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The kinetics of disappearance from the blood of GlyTyr, TyrArg, AlaTyr, TyrAla, GlnGly, GlyGln, GlnAla, and AlaGln and their constituent amino acids was assessed in anesthetized (pentabarbitone) Sprague-Dawley rats (n = 5 for each peptide). Catheters were inserted into both internal jugular veins. A bolus injection of dipeptide was administered into one catheter, and rapid blood samples were taken from the other catheter for measurement of dipeptide and amino acid concentrations. Kinetic parameters for the disappearance of dipeptides and of the amino acids released from the dipeptides from the blood were calculated using standard equations. All dipeptides were cleared rapidly from the blood (clearances ranged from 42.9 +/- 3.28 mL/min/kg body weight for GlyGln to 278 +/- 70.7 for GlnAla, mean +/- SD). Glutaminyl dipeptides with alanine or glycine in the C-terminal position or dipeptides with alanine in the N-terminal position had the greatest clearance values and the shortest half-lives (t1/2). There were significant differences (P < .001) in the volume of distribution of the dipeptides. Many dipeptides had volumes of distribution greater than the blood volume of the animals. The amino acids released from the dipeptides had a longer t1/2 (P < .001) than their parent dipeptides. The t1/2 and the weight-corrected area under the blood concentration-versus-time curve (AUC) of the same amino acid released from different dipeptides differed (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- A J Kee
- University of Sydney, NSW, Australia
| | | | | | | | | |
Collapse
|
16
|
Van Goudoever JB, Sulkers EJ, Timmerman M, Huijmans JG, Langer K, Carnielli VP, Sauer PJ. Amino acid solutions for premature neonates during the first week of life: the role of N-acetyl-L-cysteine and N-acetyl-L-tyrosine. JPEN J Parenter Enteral Nutr 1994; 18:404-8. [PMID: 7815670 DOI: 10.1177/0148607194018005404] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Tyrosine and cyst(e)ine are amino acids that are thought to be essential for preterm neonates. These amino acids have low stability (cyst(e)ine) or low solubility (tyrosine) and are therefore usually present only in small amounts in amino acid solutions. Acetylation improves the stability and solubility of amino acids, facilitating a higher concentration in the solution. We compared three commercially available amino acid solutions, Aminovenös-N-päd 10%, Vaminolact 6.5%, and Primène 10%, administered to 20 low-birth-weight neonates on total parenteral nutrition from postnatal day 2 onward. Aminovenös-N-päd 10% contains acetylated tyrosine and acetylated cysteine; the other solutions do not contain acetylated amino acids and differ in the amount of tyrosine and cysteine added. On postnatal day 7, plasma amino acids were measured together with urinary excretion of amino acids and the total nitrogen excretion; 38% of the intake of N-acetyl-L-tyrosine and 53% of the intake of N-acetyl-L-cysteine were excreted in urine. Plasma levels of N-acetyl-L-tyrosine (331 +/- 74 mumol/L) and N-acetyl-L-cysteine (18 +/- 29 mumol/L) were higher than those of tyrosine (105 +/- 108 mumol/L) and cystine (11 +/- 9 mumol/L), respectively. Plasma tyrosine levels in the groups receiving small amounts of tyrosine remained just below the reference range. We show a linear correlation of plasma cystine with the intake of cysteine (r = .75, p = 0.01), but not with N-acetyl-L-cysteine. The estimated intake of cysteine should be 500 mumol.kg-1.d-1 in order to obtain levels comparable with those shown in normal term, breast-fed neonates. Nitrogen retention did not differ among the three groups (247 to 273 mg.kg-1.d-1).(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
17
|
Abstract
The metabolic effects of intravenous peptides have undergone extensive investigation in recent years. Dipeptide solutions provide a mechanism for the provision of selected amino acids that may be conditionally indispensable under certain clinical conditions. In particular, amino acids such as cystine, glutamine, and tyrosine may be difficult to provide in their free form, but their availability can be increased substantially when they are supplied in the form of a dipeptide. Animal and human studies have demonstrated that parenteral dipeptides are cleared rapidly from the plasma compartment and favorably influence nitrogen equilibrium in healthy volunteers and catabolic patients. Certain dipeptides offer the potential for tailoring tissue-specific nutrition therapy. It seems likely that parenteral peptides will offer a major change in the delivery of intravenous nutrients.
Collapse
|
18
|
Choudhry VP, Desai N. Supportive therapy in management of leukemias. Indian J Pediatr 1993; 60:211-25. [PMID: 8244496 DOI: 10.1007/bf02822179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- V P Choudhry
- Department of Hematology, All India Institute of Medical Sciences, New Delhi
| | | |
Collapse
|
19
|
Affiliation(s)
- P Fürst
- Institute for Biological Chemistry and Nutrition, University of Hohenheim, Garbenstrasse 30, 7000 Stuttgart 70, Germany
| |
Collapse
|
20
|
Rees RG, Payne James JJ, Grimble GK, Halliday D, Frost PG, Silk DB. Glycine nitrogen in total parenteral nutrition: two prospective clinical trials comparing the efficacy of high and low glycine containing amino acid solutions. Gut 1992; 33:848-54. [PMID: 1624171 PMCID: PMC1379348 DOI: 10.1136/gut.33.6.848] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Glycine has been regarded as a poor source of nitrogen for total parenteral nutrition. Two prospective randomised cross over controlled clinical trials were undertaken to compare the efficacy of high and low glycine containing amino acid solutions in parenterally fed malnourished hypoalbuminaemic patients with gastrointestinal disease. In the first study (n = 9), amino acid solutions in which glycine accounted for 23% and 4% of total nitrogen were compared. No statistically significant difference was found in urea nitrogen/total urinary nitrogen excretion (mean (SEM) 83.4 (1.4) v 81.6 (1.7)%, p = 0.31), nitrogen balance (-1.9 (2.4) v -0.6 (2.0) g/day, p = 0.31) or plasma protein concentrations and blood urea nitrogen. In the second extended study (n = 5), there was no significant difference in net whole body protein synthesis (+1.3 (4.7) v-0.2 (3.7) mg/kg/hour, p = 0.69) or fractional (0.403 (0.070) v 0.480 (0.41)%/hour, p = 0.68) and absolute albumin synthesis rates (6.0 (0.9) v 7.2 (0.06) mg/kg/hour, p = 0.22), on comparing solutions of 25% and 8% glycine nitrogen. In addition, a significantly higher proportion of total urinary nitrogen comprised urea when patients received the low glycine containing amino acid source (81.4 (2.5) v 83.8 (3.2)%, p = 0.04). It is concluded that there are no apparent short term nutritional or metabolic disadvantages to using amino acid solutions that contain up to 25% of nitrogen as glycine in total parenteral nutrition.
Collapse
Affiliation(s)
- R G Rees
- Department of Gastroenterology and Nutrition, Central Middlesex Hospital, London
| | | | | | | | | | | |
Collapse
|
21
|
Abstract
Major thermal injury is associated with extreme hypermetabolism and catabolism as the principal metabolic manifestations encountered following successful resuscitation from the shock phase of the burn injury. Substrate and hormonal measurements, indirect calorimetry, and nitrogen balance are biochemical metabolic parameters which are useful and more readily available biochemical parameters worthy of serial assessment for the metabolic management of burn patients. However, the application of stable isotopes with gas chromatography/mass spectroscopy and more recently, new immunoassays for growth factors and cytokines has increased our understanding of the metabolic manifestations of severe trauma. The metabolic response to injury in burn patients is biphasic wherein the initial ebb phase is followed by a hypermetabolic and catabolic flow phase of injury. The increased oxygen consumption/metabolic rate is in part fuelled by evaporative heat loss from wounds of trauma victims, but likely also by a direct central effect of inflammation upon the hypothalamus. Although carbohydrates in the form of glucose appear to be an important fuel source following injury, a maximum of 5-6 mg/kg/min only is beneficial. Burn patients have accelerated gluconeogenesis, glucose oxidation, and plasma clearance of glucose. Additionally, considerable futile cycling of carbohydrate intermediates occurs which includes anaerobic lactate metabolism and Cori cycle activity arising from wound metabolism of glucose and other substrates. Similarly, accelerated lipolysis and futile fatty acid cycling occurs following burn injury. However, recent evidence suggests that lipids in the diet of burned and other injured patients serve not only as an energy source, but also as an important immunomodulator of prostaglandin metabolism and other immune responses. Amino acid metabolism in burn patients is characterized by increased oxidation, urea synthesis, and protein breakdown which is prolonged and difficult to reduce with current nutritional therapy. However, the current goal of nutritional support is to optimize protein synthesis. Specific unique requirements may exist for supplemental glutamine and arginine following burn injury but further research is needed before enhanced branched chain amino acids supplements can be recommended for burn patients. Recent research investigations have revealed the importance of enteral feeding to enhance mucosal defense against gut bacteria and endotoxin. Similarly, research has demonstrated that many of the metabolic perturbations of burns and sepsis may be due, at least in part, to inflammatory cytokines. Investigation of their pathogenesis and mechanism of action both at a tissue and a cellular level offer important prospects for improved understanding and therapeutic control of the metabolic disorders of burn patients.
Collapse
Affiliation(s)
- E E Tredget
- Firefighters' Burn Treatment Unit, University of Alberta Hospital, Canada
| | | |
Collapse
|
22
|
Druml W, Lochs H, Roth E, Hübl W, Balcke P, Lenz K. Utilization of tyrosine dipeptides and acetyltyrosine in normal and uremic humans. THE AMERICAN JOURNAL OF PHYSIOLOGY 1991; 260:E280-5. [PMID: 1996632 DOI: 10.1152/ajpendo.1991.260.2.e280] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The impact of renal failure on the elimination and hydrolysis of three sources of tyrosine for parenteral nutrition, the dipeptides alanyltyrosine (Ala-Tyr), glycyltyrosine (Gly-Tyr), and N-acetyltyrosine (NAc-Tyr) was investigated in eight patients on regular hemodialysis therapy (HD) and seven healthy controls (CON). In CON, whole body clearance (Ctot) of Ala-Tyr (3,169 +/- 198 ml/min) was higher than Gly-Tyr (1,781 +/- 184, P less than 0.001), and both exceeded NAc-Tyr (284 +/- 24, P less than 0.001). In HD, Ctot of Ala-Tyr was not different from CON, but Ctot of Gly-Tyr (858 +/- 73, P less than 0.001) and NAc-Tyr (129 +/- 30, P less than 0.02) was decreased. The rise in plasma levels of constituent amino acids was higher in Ala-Tyr vs. Gly-Tyr (P less than 0.01). In HD, the pattern was similar, although the increase in Tyr was less than in CON. Plasma Tyr did not increase with NAc-Tyr in either group. Urinary loss of peptides was neglible, but 60% of NAc-Tyr infused was excreted by CON. The half-life of peptides incubated in CON and HD plasma was unchanged for Ala-Tyr (12.3 +/- 0.9 vs. 14.6 +/- 1.9 min) and prolonged for Gly-Tyr in HD (101.7 +/- 4.9 vs. 131.3 +/- 12, P less than 0.05). Thus renal failure does not impair Ala-Tyr disposal and delays Gly-Tyr utilization. These differential effects on peptide assimilation underscore the importance of peptide structure on metabolism. Both peptides, but not NAc-Tyr, may serve as a nutritional substrate in renal failure patients.
Collapse
Affiliation(s)
- W Druml
- First Medical, Gastroenterological, and Surgical University Clinic, Vienna, Austria
| | | | | | | | | | | |
Collapse
|
23
|
|
24
|
Affiliation(s)
- P Fürst
- Institute for Biological Chemistry and Nutrition, University of Hohenheim, Garbenstraße 30, D-7000 Stuttgart 70, Germany
| |
Collapse
|
25
|
Affiliation(s)
- P Fürst
- Institute for Biological Chemistry and Nutrition, University of Hohenheim, Stuttgart, FRG
| | | | | |
Collapse
|
26
|
Lochs H, Roth E, Gasic S, Hübl W, Morse EL, Adibi SA. Splanchnic, renal, and muscle clearance of alanylglutamine in man and organ fluxes of alanine and glutamine when infused in free and peptide forms. Metabolism 1990; 39:833-6. [PMID: 2377079 DOI: 10.1016/0026-0495(90)90128-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The present study was designed to investigate organ metabolism of intravenously (IV) infused (100 mumol.h-1.kg-1) alanylglutamine and its amino acid constituents in a group of healthy subjects. The dipeptide clearance (mumol/min) by kidney (51 +/- 3) was significantly (P less than .01) greater than the clearance by either splanchnic organs (19 +/- 6) or skeletal muscle (21 +/- 8). Infusion of alanylglutamine significantly (P less than .01) increased arterial plasma concentrations of free alanine (260 +/- 31 v 330 +/- 38 mumol/L) and free glutamine (620 +/- 66 v 764 +/- 65 mumol/L) when compared with the baseline period. Concurrently, splanchnic uptake of alanine and glutamine increased and muscle release of alanine ceased. However, muscle release of glutamine remained unaffected. Renal balances of alanine and glutamine changed from neutral to negative (net release) and from positive (net uptake) to neutral, respectively. Infusion of a corresponding mixture of alanine and glutamine had similar effects on arterial plasma concentrations and splanchnic and muscle balances of alanine and glutamine, but had no effect on renal balances of these amino acids. From these studies in man, we conclude that kidney predominates over other organs in clearance of alanylglutamine from plasma and that this may account for the different effect of infusion of alanine and glutamine in free and peptide forms on renal fluxes of these amino acids.
Collapse
Affiliation(s)
- H Lochs
- 1. Univ Klinik für Gastroenterologie und Hepatologie, University of Vienna, Austria
| | | | | | | | | | | |
Collapse
|
27
|
Fürst P, Albers S, Stehle P. Glutamine-containing dipeptides in parenteral nutrition. JPEN J Parenter Enteral Nutr 1990; 14:118S-124S. [PMID: 2119457 DOI: 10.1177/014860719001400417] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Of the total pool of muscle free intracellular amino acids, glutamine represents about 60%. During catabolic stress, a marked reduction (50%) of this pool occurs; the depletion is not reversible by therapeutic efforts or conventional nutritional means. If maintenance of the intracellular glutamine pool promotes conservation of muscle protein, there is a theoretical case for use of glutamine supplements in the parenteral nutrition of patients with injury and infection. Glutamine is too unstable and poorly soluble for addition to existing preparations in its native form, but this drawback can be overcome by the use of synthetic stable and highly soluble glutamine-containing dipeptides. In vivo studies in humans and animals provide firm evidence that a synthetic glutamine-containing dipeptide, L-alanyl-L-glutamine (Ala-Gln), is readily hydrolyzed following its intravenous administration. The results also indicate a safe and efficient use of Ala-Gln as a source of free glutamine in parenteral nutrition. In clinical studies, nitrogen balance was more positive in catabolic patients receiving a peptide-supplemented solution than in control patients given isonitrogenous, isoenergetic total parenteral nutrition. Muscle glutamine concentrations were markedly decreased in the control groups. The intracellular concentrations were not influenced following severe injury, but were maintained in postoperative trauma. It is inferred that the increased intestinal requirement and cellular demand for metabolic fuel during catabolic stress is matched by an enhanced demand on muscle glutamine, resulting in intracellular glutamine depletion. Thus, the delivery of adequate amounts of glutamine is essential to maintain the integrity of intestinal mucosa and rapidly proliferating cells, to preserve the muscle glutamine pool, and to improve overall nitrogen economy during conditions of stress.
Collapse
Affiliation(s)
- P Fürst
- Institute for Biological Chemistry and Nutrition, University of Hohenheim, Stuttgart, Federal Republic of Germany
| | | | | |
Collapse
|
28
|
Vellas BJ, Balas D, Lafont C, Senegas-Balas F, Albarede JL, Ribet A. Adaptive response of pancreatic and intestinal function to nutritional intake in the aged. J Am Geriatr Soc 1990; 38:254-8. [PMID: 2107244 DOI: 10.1111/j.1532-5415.1990.tb03499.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- B J Vellas
- Department of Geriatric Medicine, CHU Purpan, Toulouse, France
| | | | | | | | | | | |
Collapse
|
29
|
Stehle P, Fürst P. In vitro hydrolysis of glutamine-, tyrosine- and cystine-containing short-chain peptides. Clin Nutr 1990; 9:37-8. [PMID: 16837322 DOI: 10.1016/0261-5614(90)90076-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- P Stehle
- Inst. Biol. Chem. and Nutrition, University of Hohenheim, Stuttgart, West Germany
| | | |
Collapse
|
30
|
Tiruppathi C, Ganapathy V, Leibach FH. Evidence for tripeptide-proton symport in renal brush border membrane vesicles. Studies in a novel rat strain with a genetic absence of dipeptidyl peptidase IV. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39938-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
31
|
Stehle P, Bahsitta HP, Monter B, Fürst P. Papain-catalysed synthesis of dipeptides: A novel approach using free amino acids as nucleophiles. Enzyme Microb Technol 1990; 12:56-60. [PMID: 1366382 DOI: 10.1016/0141-0229(90)90181-o] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
For the first time, papain-catalysed synthesis of peptide bonds was successfully carried out using free amino acids as nucleophiles. In kinetically controlled experiments employing pH-Stat-mode, the ester substrates Z-Ala-OMe and Z-Gly-OMe were coupled with alanine, glutamine, and Cys(Acm)-OH, respectively. Under optimized reaction conditions (pH 9.2, high ratio nucleophile/carboxyl component, 10 mumol substrate mg-1 papain), the peptide yields ranged from 17% to 79%, depending on the structure of the amino and/or carboxyl component. The peptides formed were not hydrolysed under the chosen reaction conditions. With Z-Gly-OMe as the ester substrate, formation of the dipeptide was both rapid and high yielding. Papain-catalysed formation of peptide bonds applying free amino acids as nucleophiles might serve as an economic and easily manageable approach for the synthesis of short-chain peptides to be used in clinical nutrition.
Collapse
Affiliation(s)
- P Stehle
- Institute for Biological Chemistry and Nutrition, University of Hohenheim, Stuttgart, FRG
| | | | | | | |
Collapse
|
32
|
Furukawa T, Hara T. Potential of γ-L-glutamyl-L-glutamine as an L-glutamine-containing dipeptide for parenteral nutrition. Amino Acids 1990. [DOI: 10.1007/978-94-011-2262-7_140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
33
|
Steininger R, Karner J, Roth E, Langer K. Infusion of dipeptides as nutritional substrates for glutamine, tyrosine, and branched-chain amino acids in patients with acute pancreatitis. Metabolism 1989; 38:78-81. [PMID: 2503685 DOI: 10.1016/0026-0495(89)90147-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In this study we investigated the effect of a total parenteral nutrition supplemented with synthetic dipeptides on plasma and muscle amino acid metabolism in four patients with acute pancreatitis. We infused an amino acid solution containing alanylglutamine, glycylglutamine, glycylvaline, glycylisoleucine, glylcylleucine, and glycyltyrosine for a period of five days in daily dosages of 10.3, 22.1, 68.8, 37.2, 42.5, and 15.7 mmol, respectively. The plasma levels remained below 100 mumol/L for all infused dipeptides. The plasma concentrations of alanylglutamine were not measurable. Mean peptide urine excretion remained below 5%, with the exception of glycylglutamine (8.5% +/- 5.1%). Arteriovenous concentration differences of the dipeptides across the leg were not significantly different from zero, indicating that the infused dipeptides have no important role in the nitrogen exchange of skeletal muscle. A marked intracellular glutamine deficiency in skeletal muscle was found in all four patients (5.1 +/- 0.6 mmol/L v 19.5 +/- 0.8 in healthy subjects) before infusion. Intracellular glutamine concentration was significantly higher after the infusion period (5.1 +/- 0.7 v 9.5 +/- 1.8 mmol/L, P greater than .05), but no normalization of the intracellular glutamine levels was achieved by the infusion of the two glutamine-containing peptides. We conclude that peptides are well metabolized as substrates for parenteral nutrition in catabolic patients. Furthermore, the infusion of glutamine peptides caused a significant increase in intracellular glutamine levels; however, the dosage of glutamine peptides was too low to normalize the muscular glutamine concentrations.
Collapse
Affiliation(s)
- R Steininger
- First Surgical University Clinic, Department of Pathophysiology, Vienna, Austria
| | | | | | | |
Collapse
|
34
|
Abumrad NN, Morse EL, Lochs H, Williams PE, Adibi SA. Possible sources of glutamine for parenteral nutrition: impact on glutamine metabolism. THE AMERICAN JOURNAL OF PHYSIOLOGY 1989; 257:E228-34. [PMID: 2504051 DOI: 10.1152/ajpendo.1989.257.2.e228] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Due to its instability, glutamine is not included in solutions for parenteral solution. This problem can be obviated by providing glutamine as acetyl-, glycyl-, or alanylglutamine. Using an organ balance technique in conscious dogs, we investigated metabolism of these three sources of glutamine. Liver, gut, kidney, and muscle participated in clearance of glycyl- and alanylglutamine from plasma, but among these organs only kidney cleared acetylglutamine. Furthermore, there was a large urinary excretion for acetylglutamine (38 +/- 6% of amount infused) but only a trace amount for either dipeptide. The infusion of glutamine-dipeptides resulted in similar increases in blood level of free glutamine. The main source of this increase appeared to be hydrolysis of dipeptides by kidney and release of free glutamine to circulation. During the infusion of both dipeptides, glutamine balance (free and dipeptide forms) was always positive (net uptake) across liver, gut, and kidney but was neutral across muscle. Liver or gut glutamine balances were not significantly different during the infusion of dipeptides, but kidney glutamine balance was twofold greater during the infusion of glycyl- than alanylglutamine. We conclude that among these three sources of glutamine, acetylglutamine is least desirable for use in parenteral nutrition. Glycylglutamine may be preferable over alanylglutamine if the objective is to target glutamine for kidney.
Collapse
Affiliation(s)
- N N Abumrad
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | | | | | | | | |
Collapse
|
35
|
Affiliation(s)
- S A Adibi
- Clinical Nutrition Unit, Montefiore Hospital, Pittsburgh, PA 15213
| |
Collapse
|
36
|
Abstract
In this review, new knowledge about the potential use of glutamine containing dipeptides as substrates in the frame of parenteral nutrition is presented. Using chemical and biotechnological methods, the stable and highly soluble peptide L-alanyl-L-glutamine (Ala-Gln) can be synthesized in high yields. Studies in experimental rats and dogs demonstrate the effective utilization of intravenously supplied Ala-Gln and the rapid provision of free glutamine for maintenance of the intracellular muscle-free glutamine pool in catabolic situations. Subsequent studies in healthy volunteers provide firm evidence that the infused Ala-Gln is rapidly eliminated from plasma (t1/2:3.8 minutes), associated by a prompt equimolar increase in the concentrations of free alanine and glutamine. Bolus injection and continuous infusion of the peptide was not accompanied by any side effects, and no complaints by the subjects were noted. These results may indicate a safe and efficient use of Ala-Gln as source of free glutamine in parenteral nutrition.
Collapse
Affiliation(s)
- P Fürst
- Institute for Biological Chemistry and Nutrition, University of Hohenheim, FRG
| | | | | |
Collapse
|
37
|
Magnusson I, Kihlberg R, Alvestrand A, Wernerman J, Ekman L, Wahren J. Utilization of intravenously administered N-acetyl-L-glutamine in humans. Metabolism 1989; 38:82-8. [PMID: 2569664 DOI: 10.1016/0026-0495(89)90148-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
L-glutamine is too unstable for inclusion in solutions for parenteral nutrition, but its acetylated analogue, N-acetyl-L-glutamine is not. The purpose of this three-part study was to investigate the utilization of intravenously (IV) administered acetylglutamine in humans. In study 1, nine healthy postabsorptive subjects were given 9.4 g acetylglutamine IV during four hours. In study 2, five healthy subjects were studied on two occasions following an overnight fast. They were given 9.4 g of acetylglutamine or an equivalent amount of glutamine as part of a total parenteral nutrition (TPN) regimen during 7.2 hours. A control group of five subjects was given the same TPN regimen, but without acetylglutamine or glutamine. The nutrient solution included glucose, amino acids, and a fat emulsion, supplying 9.4 g nitrogen and 6,300 kJ in a total volume of 1.8 L. In study 3, four patients were studied the day after major surgery. They were given the same TPN regimen as in study 2, containing 9.4 g acetylglutamine, during 7.2 hours. Plasma concentrations and urinary excretion of acetylglutamine and glutamine were measured in all three studies, and so were splanchnic and renal exchange of acetylglutamine and glutamine in study 1. In study 1, the plasma concentration of glutamine rose from 594 +/- 28 mumol/L to 728 +/- 26 mumol/L (P less than .001), whereas plasma levels of acetylglutamine exceeded 1,000 mumol/L in all subjects at the end of infusion. The eight-hour urinary excretion of acetylglutamine and glutamine corresponded to 18% of the infused amount of acetylglutamine.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- I Magnusson
- Department of Clinical Physiology, Huddinge Hospital, Sweden
| | | | | | | | | | | |
Collapse
|
38
|
Abumrad NN, Williams P, Frexes-Steed M, Geer R, Flakoll P, Cersosimo E, Brown LL, Melki I, Bulus N, Hourani H. Inter-organ metabolism of amino acids in vivo. DIABETES/METABOLISM REVIEWS 1989; 5:213-26. [PMID: 2656153 DOI: 10.1002/dmr.5610050302] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- N N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Stehle P, Zander J, Mertes N, Albers S, Puchstein C, Lawin P, Fürst P. Effect of parenteral glutamine peptide supplements on muscle glutamine loss and nitrogen balance after major surgery. Lancet 1989; 1:231-3. [PMID: 2563409 DOI: 10.1016/s0140-6736(89)91254-3] [Citation(s) in RCA: 307] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Twelve patients admitted for elective resection of carcinoma of colon or rectum were allocated at random to experimental and control groups (six in each) and received a total parenteral nutrition regimen providing 230 mg N/kg and 166 KJ/kg daily over the first 5 postoperative days. In the experimental group the parenteral fluid was supplemented with a synthetic glutamine-containing dipeptide, L-alanyl-L-glutamine (54 mg peptide-N/kg per day) and the control group received corresponding amounts of alanine-N and glycine-N. On each postoperative day nitrogen balance was better in the experimental group; mean daily nitrogen balance with alanyl-glutamine was -1.5 (SE 0.4) g N/day and with the control solution -3.6 (0.2) g N/day. The cumulative nitrogen balances on the fifth postoperative day were -7.1 (2.2) and -18.1 (1.7) g N, respectively. With the peptide-containing solution intramuscular glutamine concentration remained close to the preoperative value whereas with the control solution it decreased from 19.7 (SE 0.9) to 12.0 (0.6) mmol/l intracellular water.
Collapse
Affiliation(s)
- P Stehle
- Institute for Biological Chemistry and Nutrition, University of Hohenheim, Stuttgart, Federal Republic of Germany
| | | | | | | | | | | | | |
Collapse
|
40
|
|