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Pathway Description
Ethanol Degradation
Homo sapiens
Metabolic Pathway
Created: 2013-08-01
Last Updated: 2022-10-18
Ethanol metabolism in humans occurs mainly in the liver, though degradation has also been shown in gastric, pancreatic, and lung tissue. Ethanol degradation occurs via four pathways, three of which are oxidative pathways and are depicted here. The fourth is a nonoxidative pathway which is less well studied but known to produce fatty acid ethyl esters. Each of the three oxidative pathways is differentiated by the mechanism utilized to oxidize ethanol to acetaldehyde in the first step. In the alcohol dehydrogenase mediated ethanol degradation pathway (I), cytoplasmic alcohol dehydrogenase produces the acetaldehyde from the ethanol. In the MEOS mediated ethanol degradation pathway (II), the ethanol enters the endoplasmic reticulum, where the Microsomal Ethanol Oxidising System (MEOS), also know as also known as cytochrome P-450 2E1, does the oxidizing and returns the acetaldehyde to the cytoplasm. In the catalase mediated ethanol degradation pathway (III), the oxidation occurs in the peroxisome via peroxisomal catalase, with the resulting acetaldehyde being released to the cytoplasm. In each of the three oxidative pathways the cytosolic acetaldehyde then enters the mitochondrial compartment, where it is converted to acetate by mitochondrial aldehyde dehydrogenase. The acetate leaves the mitochondria and moves to extra-hepatic tissues for further metabolism. In extra-hepatic cells the acetate is converted to acetyl-CoA via either cytoplasmic or mitochondrial acetyl-CoA synthetase. The alcohol dehydrogenase mediated ethanol degradation pathway (I) is the predominant mechanism of catabolism under conditions of acute alcohol consumption. However, under conditions of chronic ethanol consumption the MEOS mediated ethanol degradation pathway (II) and nonoxidative pathway are induced to assist with ethanol degradation.
References
Ethanol Degradation References
Best CA, Laposata M: Fatty acid ethyl esters: toxic non-oxidative metabolites of ethanol and markers of ethanol intake. Front Biosci. 2003 Jan 1;8:e202-17.
Pubmed: 12456329
Salway, J.G. Metabolism at a glance (3rd ed.) (2004). Alden, Mass.: Blackwell Pub.
Waluga M, Hartleb M: [Alcoholic liver disease]. Wiad Lek. 2003;56(1-2):61-70.
Pubmed: 12901271
Yamashita H, Kaneyuki T, Tagawa K: Production of acetate in the liver and its utilization in peripheral tissues. Biochim Biophys Acta. 2001 May 31;1532(1-2):79-87.
Pubmed: 11420176
Ikuta T, Fujiyoshi T, Kurachi K, Yoshida A: Molecular cloning of a full-length cDNA for human alcohol dehydrogenase. Proc Natl Acad Sci U S A. 1985 May;82(9):2703-7. doi: 10.1073/pnas.82.9.2703.
Pubmed: 2986130
Heden LO, Hoog JO, Larsson K, Lake M, Lagerholm E, Holmgren A, Vallee BL, Jornvall H, von Bahr-Lindstrom H: cDNA clones coding for the beta-subunit of human liver alcohol dehydrogenase have differently sized 3'-non-coding regions. FEBS Lett. 1986 Jan 6;194(2):327-32. doi: 10.1016/0014-5793(86)80111-9.
Pubmed: 3000832
Duester G, Smith M, Bilanchone V, Hatfield GW: Molecular analysis of the human class I alcohol dehydrogenase gene family and nucleotide sequence of the gene encoding the beta subunit. J Biol Chem. 1986 Feb 15;261(5):2027-33.
Pubmed: 2935533
Novoradovsky A, Tsai SJ, Goldfarb L, Peterson R, Long JC, Goldman D: Mitochondrial aldehyde dehydrogenase polymorphism in Asian and American Indian populations: detection of new ALDH2 alleles. Alcohol Clin Exp Res. 1995 Oct;19(5):1105-10. doi: 10.1111/j.1530-0277.1995.tb01587.x.
Pubmed: 8561277
Braun T, Bober E, Singh S, Agarwal DP, Goedde HW: Evidence for a signal peptide at the amino-terminal end of human mitochondrial aldehyde dehydrogenase. FEBS Lett. 1987 May 11;215(2):233-6. doi: 10.1016/0014-5793(87)80152-7.
Pubmed: 3582651
Braun T, Bober E, Singh S, Agarwal DP, Goedde HW: Isolation and sequence analysis of a full length cDNA clone coding for human mitochondrial aldehyde dehydrogenase. Nucleic Acids Res. 1987 Apr 10;15(7):3179. doi: 10.1093/nar/15.7.3179.
Pubmed: 3562250
Hu Y, Oscarson M, Johansson I, Yue QY, Dahl ML, Tabone M, Arinco S, Albano E, Ingelman-Sundberg M: Genetic polymorphism of human CYP2E1: characterization of two variant alleles. Mol Pharmacol. 1997 Mar;51(3):370-6.
Pubmed: 9058590
Fairbrother KS, Grove J, de Waziers I, Steimel DT, Day CP, Crespi CL, Daly AK: Detection and characterization of novel polymorphisms in the CYP2E1 gene. Pharmacogenetics. 1998 Dec;8(6):543-52.
Pubmed: 9918138
Song BJ, Gelboin HV, Park SS, Yang CS, Gonzalez FJ: Complementary DNA and protein sequences of ethanol-inducible rat and human cytochrome P-450s. Transcriptional and post-transcriptional regulation of the rat enzyme. J Biol Chem. 1986 Dec 15;261(35):16689-97.
Pubmed: 3782137
Quan F, Korneluk RG, Tropak MB, Gravel RA: Isolation and characterization of the human catalase gene. Nucleic Acids Res. 1986 Jul 11;14(13):5321-35. doi: 10.1093/nar/14.13.5321.
Pubmed: 3755525
Bell GI, Najarian RC, Mullenbach GT, Hallewell RA: cDNA sequence coding for human kidney catalase. Nucleic Acids Res. 1986 Jul 11;14(13):5561-2.
Pubmed: 3755526
Jin LH, Bahn JH, Eum WS, Kwon HY, Jang SH, Han KH, Kang TC, Won MH, Kang JH, Cho SW, Park J, Choi SY: Transduction of human catalase mediated by an HIV-1 TAT protein basic domain and arginine-rich peptides into mammalian cells. Free Radic Biol Med. 2001 Dec 1;31(11):1509-19.
Pubmed: 11728823
Luong A, Hannah VC, Brown MS, Goldstein JL: Molecular characterization of human acetyl-CoA synthetase, an enzyme regulated by sterol regulatory element-binding proteins. J Biol Chem. 2000 Aug 25;275(34):26458-66. doi: 10.1074/jbc.M004160200.
Pubmed: 10843999
Ota T, Suzuki Y, Nishikawa T, Otsuki T, Sugiyama T, Irie R, Wakamatsu A, Hayashi K, Sato H, Nagai K, Kimura K, Makita H, Sekine M, Obayashi M, Nishi T, Shibahara T, Tanaka T, Ishii S, Yamamoto J, Saito K, Kawai Y, Isono Y, Nakamura Y, Nagahari K, Murakami K, Yasuda T, Iwayanagi T, Wagatsuma M, Shiratori A, Sudo H, Hosoiri T, Kaku Y, Kodaira H, Kondo H, Sugawara M, Takahashi M, Kanda K, Yokoi T, Furuya T, Kikkawa E, Omura Y, Abe K, Kamihara K, Katsuta N, Sato K, Tanikawa M, Yamazaki M, Ninomiya K, Ishibashi T, Yamashita H, Murakawa K, Fujimori K, Tanai H, Kimata M, Watanabe M, Hiraoka S, Chiba Y, Ishida S, Ono Y, Takiguchi S, Watanabe S, Yosida M, Hotuta T, Kusano J, Kanehori K, Takahashi-Fujii A, Hara H, Tanase TO, Nomura Y, Togiya S, Komai F, Hara R, Takeuchi K, Arita M, Imose N, Musashino K, Yuuki H, Oshima A, Sasaki N, Aotsuka S, Yoshikawa Y, Matsunawa H, Ichihara T, Shiohata N, Sano S, Moriya S, Momiyama H, Satoh N, Takami S, Terashima Y, Suzuki O, Nakagawa S, Senoh A, Mizoguchi H, Goto Y, Shimizu F, Wakebe H, Hishigaki H, Watanabe T, Sugiyama A, Takemoto M, Kawakami B, Yamazaki M, Watanabe K, Kumagai A, Itakura S, Fukuzumi Y, Fujimori Y, Komiyama M, Tashiro H, Tanigami A, Fujiwara T, Ono T, Yamada K, Fujii Y, Ozaki K, Hirao M, Ohmori Y, Kawabata A, Hikiji T, Kobatake N, Inagaki H, Ikema Y, Okamoto S, Okitani R, Kawakami T, Noguchi S, Itoh T, Shigeta K, Senba T, Matsumura K, Nakajima Y, Mizuno T, Morinaga M, Sasaki M, Togashi T, Oyama M, Hata H, Watanabe M, Komatsu T, Mizushima-Sugano J, Satoh T, Shirai Y, Takahashi Y, Nakagawa K, Okumura K, Nagase T, Nomura N, Kikuchi H, Masuho Y, Yamashita R, Nakai K, Yada T, Nakamura Y, Ohara O, Isogai T, Sugano S: Complete sequencing and characterization of 21,243 full-length human cDNAs. Nat Genet. 2004 Jan;36(1):40-5. doi: 10.1038/ng1285. Epub 2003 Dec 21.
Pubmed: 14702039
Deloukas P, Matthews LH, Ashurst J, Burton J, Gilbert JG, Jones M, Stavrides G, Almeida JP, Babbage AK, Bagguley CL, Bailey J, Barlow KF, Bates KN, Beard LM, Beare DM, Beasley OP, Bird CP, Blakey SE, Bridgeman AM, Brown AJ, Buck D, Burrill W, Butler AP, Carder C, Carter NP, Chapman JC, Clamp M, Clark G, Clark LN, Clark SY, Clee CM, Clegg S, Cobley VE, Collier RE, Connor R, Corby NR, Coulson A, Coville GJ, Deadman R, Dhami P, Dunn M, Ellington AG, Frankland JA, Fraser A, French L, Garner P, Grafham DV, Griffiths C, Griffiths MN, Gwilliam R, Hall RE, Hammond S, Harley JL, Heath PD, Ho S, Holden JL, Howden PJ, Huckle E, Hunt AR, Hunt SE, Jekosch K, Johnson CM, Johnson D, Kay MP, Kimberley AM, King A, Knights A, Laird GK, Lawlor S, Lehvaslaiho MH, Leversha M, Lloyd C, Lloyd DM, Lovell JD, Marsh VL, Martin SL, McConnachie LJ, McLay K, McMurray AA, Milne S, Mistry D, Moore MJ, Mullikin JC, Nickerson T, Oliver K, Parker A, Patel R, Pearce TA, Peck AI, Phillimore BJ, Prathalingam SR, Plumb RW, Ramsay H, Rice CM, Ross MT, Scott CE, Sehra HK, Shownkeen R, Sims S, Skuce CD, Smith ML, Soderlund C, Steward CA, Sulston JE, Swann M, Sycamore N, Taylor R, Tee L, Thomas DW, Thorpe A, Tracey A, Tromans AC, Vaudin M, Wall M, Wallis JM, Whitehead SL, Whittaker P, Willey DL, Williams L, Williams SA, Wilming L, Wray PW, Hubbard T, Durbin RM, Bentley DR, Beck S, Rogers J: The DNA sequence and comparative analysis of human chromosome 20. Nature. 2001 Dec 20-27;414(6866):865-71. doi: 10.1038/414865a.
Pubmed: 11780052
Gerhard DS, Wagner L, Feingold EA, Shenmen CM, Grouse LH, Schuler G, Klein SL, Old S, Rasooly R, Good P, Guyer M, Peck AM, Derge JG, Lipman D, Collins FS, Jang W, Sherry S, Feolo M, Misquitta L, Lee E, Rotmistrovsky K, Greenhut SF, Schaefer CF, Buetow K, Bonner TI, Haussler D, Kent J, Kiekhaus M, Furey T, Brent M, Prange C, Schreiber K, Shapiro N, Bhat NK, Hopkins RF, Hsie F, Driscoll T, Soares MB, Casavant TL, Scheetz TE, Brown-stein MJ, Usdin TB, Toshiyuki S, Carninci P, Piao Y, Dudekula DB, Ko MS, Kawakami K, Suzuki Y, Sugano S, Gruber CE, Smith MR, Simmons B, Moore T, Waterman R, Johnson SL, Ruan Y, Wei CL, Mathavan S, Gunaratne PH, Wu J, Garcia AM, Hulyk SW, Fuh E, Yuan Y, Sneed A, Kowis C, Hodgson A, Muzny DM, McPherson J, Gibbs RA, Fahey J, Helton E, Ketteman M, Madan A, Rodrigues S, Sanchez A, Whiting M, Madari A, Young AC, Wetherby KD, Granite SJ, Kwong PN, Brinkley CP, Pearson RL, Bouffard GG, Blakesly RW, Green ED, Dickson MC, Rodriguez AC, Grimwood J, Schmutz J, Myers RM, Butterfield YS, Griffith M, Griffith OL, Krzywinski MI, Liao N, Morin R, Palmquist D, Petrescu AS, Skalska U, Smailus DE, Stott JM, Schnerch A, Schein JE, Jones SJ, Holt RA, Baross A, Marra MA, Clifton S, Makowski KA, Bosak S, Malek J: The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). Genome Res. 2004 Oct;14(10B):2121-7. doi: 10.1101/gr.2596504.
Pubmed: 15489334
Hsu LC, Chang WC: Cloning and characterization of a new functional human aldehyde dehydrogenase gene. J Biol Chem. 1991 Jul 5;266(19):12257-65.
Pubmed: 2061311
Humphray SJ, Oliver K, Hunt AR, Plumb RW, Loveland JE, Howe KL, Andrews TD, Searle S, Hunt SE, Scott CE, Jones MC, Ainscough R, Almeida JP, Ambrose KD, Ashwell RI, Babbage AK, Babbage S, Bagguley CL, Bailey J, Banerjee R, Barker DJ, Barlow KF, Bates K, Beasley H, Beasley O, Bird CP, Bray-Allen S, Brown AJ, Brown JY, Burford D, Burrill W, Burton J, Carder C, Carter NP, Chapman JC, Chen Y, Clarke G, Clark SY, Clee CM, Clegg S, Collier RE, Corby N, Crosier M, Cummings AT, Davies J, Dhami P, Dunn M, Dutta I, Dyer LW, Earthrowl ME, Faulkner L, Fleming CJ, Frankish A, Frankland JA, French L, Fricker DG, Garner P, Garnett J, Ghori J, Gilbert JG, Glison C, Grafham DV, Gribble S, Griffiths C, Griffiths-Jones S, Grocock R, Guy J, Hall RE, Hammond S, Harley JL, Harrison ES, Hart EA, Heath PD, Henderson CD, Hopkins BL, Howard PJ, Howden PJ, Huckle E, Johnson C, Johnson D, Joy AA, Kay M, Keenan S, Kershaw JK, Kimberley AM, King A, Knights A, Laird GK, Langford C, Lawlor S, Leongamornlert DA, Leversha M, Lloyd C, Lloyd DM, Lovell J, Martin S, Mashreghi-Mohammadi M, Matthews L, McLaren S, McLay KE, McMurray A, Milne S, Nickerson T, Nisbett J, Nordsiek G, Pearce AV, Peck AI, Porter KM, Pandian R, Pelan S, Phillimore B, Povey S, Ramsey Y, Rand V, Scharfe M, Sehra HK, Shownkeen R, Sims SK, Skuce CD, Smith M, Steward CA, Swarbreck D, Sycamore N, Tester J, Thorpe A, Tracey A, Tromans A, Thomas DW, Wall M, Wallis JM, West AP, Whitehead SL, Willey DL, Williams SA, Wilming L, Wray PW, Young L, Ashurst JL, Coulson A, Blocker H, Durbin R, Sulston JE, Hubbard T, Jackson MJ, Bentley DR, Beck S, Rogers J, Dunham I: DNA sequence and analysis of human chromosome 9. Nature. 2004 May 27;429(6990):369-74. doi: 10.1038/nature02465.
Pubmed: 15164053
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