title: Nutritional efficiency of succinic acid and glutamic acid dimethyl esters in colon carcinoma cells.
abstract: The dimethyl esters of succinic acid (SAD) and glutamic acid (GME) were found to be efficiently metabolized in colon carcinoma cells of the Caco-2 line. The rate of [1,4-14C]SAD and [2,3-14C]SAD conversion to radioactive acidic metabolites, CO2, amino acids, pyruvic acid, and lactic acid suggested that the catabolism of the ester-derived succinic acid occurred mainly through the sequence of reactions catalyzed by succinate dehydrogenase, fumarase, and the malic enzyme. This coincided with a marked sparing action of SAD on the utilization of D-[2-(3)H]glucose and D-[5-(3)H]glucose and generation of 14C-labeled acid metabolites, CO2, and lactic acid from D-[U-14C]glucose by the enterocytes. Likewise, the conversion of [U-14C]GME to 14C-labeled amino acids, its oxidation compared with that of [1-(14)C]GME, and the production of NH4+ in the absence or presence of GME indicated efficient catabolism of the latter ester. Like SAD, GME decreased the utilization of D-[5-(3)H]glucose and generation of 14C-labeled acidic metabolites, pyruvate, and CO2 from D-[6-(14)C]glucose, while increasing the generation of 14C-labeled amino acids from the labeled hexose. The oxidation of D-[6-(14)C]glucose was even more severely inhibited by GME. In normal rat intestinal cells, SAM, SAD, and GME also exerted a marked sparing action on D-[U-14C]glucose oxidation. The present findings suggest, therefore, that these esters could possibly be used to sustain ATP generation in intestinal cells.
authors.affiliation: Laboratory of Experimental Medicine, Brussels Free University, Belgium.
authors.forename: T M
authors.initials: TM
authors.lastname: Zhang
authors.forename: H
authors.initials: H
authors.lastname: Jijakli
authors.forename: W J
authors.initials: WJ
authors.lastname: Malaisse
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D018938:Caco-2 Cells / Q000187:drug effects / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism* / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000166:cytology; D009747:Nutritional Physiological Phenomena; D010084:Oxidation-Reduction / Q000187:drug effects; D012016:Reference Values; D013386:Succinates / Q000378:metabolism* / Q000494:pharmacology; D019802:Succinic Acid
chemical_list: D005971:Glutamates; D013386:Succinates; D018698:Glutamic Acid; C035873:glutamic acid dimethyl ester; D000255:Adenosine Triphosphate; D019802:Succinic Acid; D005947:Glucose