[Effect of ethanol on synthesis of serine and exchange of methyl groups in hepatocytes by NMR spectroscopy].
The method of NMR spectroscopy was used to investigate the role of voltage-dependent anion channels in the outer mitochondrial membrane in the mechanism of ethanol hepatotoxicity using the synthesis of serine and exchange of methyl groups in hepatocytes metabolizing 13C-labeled glycine. Here we present and describe a methodological approach developed for the independent monitoring of the synthesis of serine in two intracellular compartments: the cytoplasm and mitochondria of intact hepatocytes, and quantification of different serine isotopomers synthesized in hepatocytes from 13C-labeled glycine. The data obtained indicate that the treatment of cells with ethanol as well as cysteamine (specific inhibitor of mitochondrial synthesis of serine) suppressed the level of mitochondria but not cytoplasmic serine isotopomers. It is concluded that the decrease in the production of mitochondrial serine isotopomers in hepatocytes exposed to ethanol can be caused not only by decreased permeability of the outer mitochondrial membrane due to the closure of voltage-dependent anion channels and suppression of the exchange of substrates of serine synthesis in mitochondria but also by the restoration of the cytoplasmic and/or mitochondrial pool of pyridine nucleotides (NADH) during the oxidation of ethanol. Our work reveals a new mechanism of action of ethanol (alcohol intoxication) in hepatocytes through the regulation of glycine metabolism and opens new possibilities in the treatment of alcohol poisoning.
E L
EL
Kholmukhamedov
V V
VV
Teplova
C B
CB
Johnson
J
J
MacDonald
D000818:Animals; D003543:Cysteamine / Q000494:pharmacology; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D000431:Ethanol / Q000494:pharmacology*; D005998:Glycine / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D008715:Methionine / Q000378:metabolism; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D012694:Serine / Q000037:antagonists & inhibitors / Q000096:biosynthesis*
D000431:Ethanol; D012694:Serine; D003543:Cysteamine; D008715:Methionine; D005998:Glycine