Plasma Aspartate Levels in Rats Following Administration of Monopotassium Aspartate via Three Routes

Itoh, Hiroshi; Kishi, Tohru; Iwasawa, Yasuo; Kawashima, Keisuke; Chibata, Ichiro

doi:10.2131/jts.4.377

Cited by 4 publications

(4 citation statements)

References 16 publications

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“…Studies by Itoh and co-workers [19] demonstrated that peak plasma concentrations of a radioactive amino acid were obtained -15 min after ip injection of rats followed by rapid disappearance. Barton [20] demonstrated that the concentration of free labeled amino acid in liver peaked at -30 min with subsequent rapid decline similar to that observed in plasma.…”

Section: Resultsmentioning

confidence: 99%

In vivo biosynthesis of clathrin and other coated vesicle proteins from rat liver

Pierce

Zurzolo

Edelhoch

1986

J of Cellular Biochemistry

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A biosynthetic study of rat liver coated vesicle (CV) proteins was undertaken by using in vivo labeling with L-[35S]methionine. CVs were isolated and purified by using standard procedures and characterized by electron microscopy, sedimentation, and sodium dodecyl sulfate polyacrylamide gel electrophoresis followed by fluorography, or by gel slicing and liquid scintillation counting. After 5 1/2 min of labeling (the earliest time examined), incorporation of radioactive clathrin heavy-chain (180-kD (kilodalton] subunits as well as a 90-kD CV-associated protein into purified CVs was demonstrated. The level of labeled 180-kD clathrin in coated vesicles increased rapidly during the first 2 hr of labeling and then continued to rise at a slower rate between 4 and 16 hr. This slow accumulation of labeled clathrin heavy chains in the CV pool may reflect early compartmental sequestration of a fraction of newly synthesized clathrin with delayed assembly into free CVs. By 16 hr of labeling, clathrin 180-kD chains and the 90-kD CV-associated protein accounted for approximately 48 and 26%, respectively, of the radioactivity in all CV proteins. Two proteins of MWa 68 kD and 53 kD showed marked declines in cpm/unit protein between 30 min and 4 hr, raising the possibility that these species may be transferred out of CVs during or after transport without loss of the other CV proteins. The possibility is also raised that clathrin heavy chains may be recycled during CV formation. Possible heterogeneity within individual CV preparations with respect to protein composition and derivation from both plasma membrane and Golgi regions are proposed.

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Section: Resultsmentioning

confidence: 99%

In vivo biosynthesis of clathrin and other coated vesicle proteins from rat liver

Pierce

Zurzolo

Edelhoch

1986

J of Cellular Biochemistry

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“…Doses of aspartate or glutamate that produce plasma glutamate plus aspartate concentrations lower than 60 pmol/dl (6 to 10 times normal) do not produce lesions in the infant rodent (44)(45)(46)(47)(48)(49). Lesions are noted only when very large doses of glutamate or aspartate are administered and plasma glutamate plus aspartate concentrations exceed 60 to 100 pmol/dl.…”

Section: Discussionmentioning

confidence: 99%

Plasma Glutamate Concentrations in 1-Year-Old Infants and Adults Ingesting Monosodium L-Glutamate in Consommé

et al. 1986

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ABSTRACT. This study tested the hypothesis that infants metabolize glutamate more slowly than adults. Eight l-yrold infants ingested 160 ml of a beef consommi: providing monosodium L-glutamate at 0, 25, and 50 mg/kg body weight. Plasma glutamate and aspartate concentrations were measured sequentially for the next 2 h. The results were compared to values noted in nine adult subjects ingesting equivalent doses of monosodium L-glutamate in consomme. In adults, mean (+ SD) peak plasma glutamate concentrations were 5.59 f 1.56, 10.2 + 2.08, and 17.0 f The ability of human infants to metabolize MSG has been one area of concern in considering glutamate's safety as a food additive. Olney (1-3) postulated that human infants metabolized dicarboxylic amino acids more slowly than adults, and projected theoretical plasma glutamate concentrations for infants at much higher values than those for adults following glutamate ingestion.The present study directly tested this hypothesis by measuring the plasma glutamate and aspartate response in 1-yr-old infants fed a beef consommi containing graded doses of MSG. The results of these studies were compared with previously reported (4) plasma glutamate and aspartate values in normal adults administered equivalent doses of MSG in the same consomm6. MATERIALS AND METHODSEight infants (four male, four female) were studied. The proposed study was explained to at least one of the parents and informed, written consent was obtained. The protocol of the study was reviewed and approved by the Committee on Research Involving Human Subjects of the University of Iowa.Each child ingested 160 ml of beef consommC providing 0,25, and 50 mg/kg body weight of added MSG in a balanced crossover design. Each infant was randomly assigned to receive consommi providing either 0 or 25 mg MSG/kg body weight, followed by the other dose at least 1 wk later. After these two tests had been completed and the results evaluated, each infant ingested consommi providing MSG at 50 mg/kg body weight. All tests were begun at 0800 h following an overnight fast.The monohydrate of monosodium L-glutamate was purchased from a local grocery store (Accent International, Pet Incorporated, St. Louis MO). The soup was prepared from a special beef consommk base supplied by the Ajinomoto Company (Tokyo, Japan). The composition of the soup base is shown in Table 1. As noted in Table 1, 160 ml of reconstituted soup contained 37 mg of free glutamate, for a mean dose of 4.1 mg/kg body weight. Thus, the true final doses of MSG studied in these infants were 4.1, 29.1 and 54.1 mg/kg body weight.Each infant was assigned by random allocation into one of two equal groups that differed with respect to time of blood sampling. Since only four blood samples were obtained from each infant after dosing, two different sampling schedules were utilized so as to obtain samples during the entire absorptive period. Blood samples at each dose level were obtained from four infants at 0, 30, 60, and 120 min After ingestion of the consommG Blood samples from ...

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“…Oral administration by gavage to Wistar rats (7,21 and 35 days old) of 1.9 and 3.8 g potassium aspartate 5 / kg body weight, slowly increased plasma aspartate levels reaching a maximum of 30 to 90 min after administration (44 and 98 µmoles/100 ml, respectively) (Itoh et al 1979). Control aspartate plasma levels (~ 3 µmoles/100 ml) were attained 4 hours after administration.…”

Section: Metabolic Fate Of the Source And Biological Distributionmentioning

confidence: 94%

“…Oral administration by gavage of 1.9 and 3.8 g potassium aspartate/kg bw (assuming a mean potassium content of 20 %, this dosage would be equivalent to approximately 1.5 and 3.0 g aspartate/ kg bw, respectively) of at least 5 male Wistar rats to groups of animals aged 7, 21 and 35 days old, did not affect free amino acids levels in plasma except for aspartic acid, glutamic acid, alanine and proline (Itoh et al, 1979). It was reported that oral administration of 3.8 g potassium aspartate/kg bw, leading to aspartate plasma levels of 66 µmoles/100 ml, induced hypothalamic lesions in 50 % of the 7-days old rats group.…”

Section: Animal Datamentioning

confidence: 99%

Magnesium aspartate, potassium aspartate, magnesium potassium aspartate, calcium aspartate, zinc aspartate, and copper aspartate as sources for magnesium, potassium, calcium, zinc, and copper added for nutritional purposes to food supplements - Scientific

2008

EFSA Journal

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Plasma Aspartate Levels in Rats Following Administration of Monopotassium Aspartate via Three Routes

Cited by 4 publications

References 16 publications

In vivo biosynthesis of clathrin and other coated vesicle proteins from rat liver

In vivo biosynthesis of clathrin and other coated vesicle proteins from rat liver

Plasma Glutamate Concentrations in 1-Year-Old Infants and Adults Ingesting Monosodium L-Glutamate in Consommé

Magnesium aspartate, potassium aspartate, magnesium potassium aspartate, calcium aspartate, zinc aspartate, and copper aspartate as sources for magnesium, potassium, calcium, zinc, and copper added for nutritional purposes to food supplements - Scientific

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