Absorption, Distribution and Excretion
Glutamate is absorbed from the gut by an active transport system specific for amino acids. This process is saturable, can be competitively inhibited, and is dependent on sodium ion concentration... . During intestinal absorption, a large proportion of glutamic acid is transaminated and consequently alanine levels in portal blood are elevated. If large amounts of glutamate are ingested, portal glutamate levels increase ... . This elevation results in increased hepatic metabolism of glutamate, leading to release of glucose, lactate, glutamine, and other amino acids, into systemic circulation ... . The pharmacokinetics of glutamate depend on whether it is free or incorporated into protein, and on the presence of other food components. Digestion of protein in the intestinal lumen and at the brush border produces a mixture of small peptides and amino acids; di-and tri-peptides may enter the absorptive cells where intracellular hydrolysis may occur, liberating further amino acids. Defects are known in both amino acid and peptide transport ... .. Glutamic acid in dietary protein, together with endogenous protein secreted into the gut, is digested to free amino acids and small peptides, both of which are absorbed into mucosal cells where peptides are hydrolyzed to free amino acids and some of the glutamate is metabolized. Excess glutamate and other amino acids appear in portal blood. As a consequence of the rapid metabolism of glutamate in intestinal mucosal cells and in the liver, systemic plasma levels are low, even after ingestion of large amounts of dietary protein. /Glutamic acid/
... Intestinal and hepatic metabolism results in elevation of levels in systemic circulation only after extremely high doses given by gavage (>30mg/kg body weight). Ingestion of monosodium glutamate (MSG) was not associated with elevated levels in maternal milk, and glutamate did not readily pass the placental barrier. Human infants metabolized glutamate similarly to adults.
Oral administration of pharmacologically high doses of glutamate results in elevated plasma levels. The peak plasma glutamate levels are both dose and concentration dependent ... . When the same dose (1 g/kg b.w.) of monosodium glutamate (MSG) was administered by gavage in aqueous solution to neonatal rats, increasing the concentration from 2% to 10% caused a five-fold increase in the plasma area under curve; similar results were observed in mice ... . Conversely, when MSG (1.5 g/kg b.w.) was administered to 43-day-old mice by gavage at varying concentrations of 2 to 20% w/v, no correlation could be established between plasma levels and concentration ...
Administration of a standard dose of 1 g/kg b.w. MSG by gavage as a 10% w/v solution resulted in a marked increase of plasma glutamate in all species studied. Peak plasma glutamate levels were lowest in adult monkeys (6 times fasting levels) and highest in mice (12-35 times fasting levels). Age-related differences between neonates and adults were observed; in mice and rats, peak plasma levels and area under curve were higher in infants than in adults while in guinea pigs the converse was observed.
For more Absorption, Distribution and Excretion (Complete) data for MONOSODIUM GLUTAMATE (7 total), please visit the HSDB record page.

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Metabolism / Metabolites
Glutamic acid is metabolized in the tissues by oxidative deamination ... or by transamination with pyruvate to yield oxaloacetic acid ... which, via alpha-ketoglutarate, enters the citric acid cycle ... .. Quantitatively minor but physiologically important pathways of glutamate metabolism involve decarboxylation to gamma-aminobutyrate (GABA) and amidation to glutamine ... . Decarboxylation to GABA is dependent on pyridoxal phosphate, a coenzyme of glutamic acid decarboxylase ..., as is glutamate transaminase. Vitamin B6-deficient rats have elevated serum glutamate levels and delayed glutamate clearance ... . /Glutamic acid/
Oral dose of 1 g/kg monosodium glutamate given to rats was followed by only a small rise in plasma pyroglutamate levels. No incr of pyroglutamate or glutamate brain levels was observed under these conditions.

[1]. MEASUREMENT OF DNA DAMAGE, OXIDATIVE STRESS, AND GENE EXPRESSION OF β-CATENIN AND P53 GENES IN LIVER AND BRAIN OF MALE MICE RECEIVING MONOSODIUM L-GLUTAMATE MONOHYDRATE. MEASUREMENT, 2020, 13(7).

Monosodium glutamate appears as white or off-white crystalline powder with a slight peptone-like odor. pH (0.2% solution)7.0. (NTP, 1992)
One of the FLAVORING AGENTS used to impart a meat-like flavor.
See also: Glutamic Acid (has active moiety) ... View More ...

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Mechanism of Action
L-Glutamate and GABA supposedly act as excitatory and inhibitory transmitters, respectively, in the central nervous system. Glutamate is also involved in the synthesis of proteins. /Glutamate/

C5H10NNAO5

187.13

187.045

6106-04-3

L-Glutamic acid-13C5 hydrate salt;202114-62-3

23672308

White free flowing crystals or crystalline powder
Forms rhombic prisms when crystallized from water

333.8ºC at 760 mmHg

232 °C (dec.)(lit.)

155.7ºC

2

5

4

11

149

1

O([H])C([C@]([H])(C([H])([H])C([H])([H])C(=O)O[H])N([H])[H])=O

LPUQAYUQRXPFSQ-DFWYDOINSA-M

InChI=1S/C5H9NO4.Na/c6-3(5(9)10)1-2-4(7)8;/h3H,1-2,6H2,(H,7,8)(H,9,10);/q;+1/p-1/t3-;/m0./s1

sodium;(2S)-2-amino-5-hydroxy-5-oxopentanoate

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O: 100 mg/mL (534.39 mM)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)