Mitochondria as the primary site of acetaldehyde metabolism in beef and pig liver slices.
Aldehyde dehydrogenase (ALDH) is the major enzyme involved in the oxidation of acetaldehyde. It has been shown that the liver enzyme is located in both cytosol and mitochondria. It has not been established where the subcellular oxidation of acetaldehyde occurs in species other than rat. Using slices isolated from beef and pig livers and selectively inhibiting the mitochondria enzyme with cyanamide or the cytosolic enzyme with disulfiram, it was possible to address this question. It was found that with both beef and pig liver slices 60% of the oxidation was catalyzed by the mitochondrial ALDH and 20% by the higher Km cytosolic enzyme. The remainder of the metabolism was the result of non-ALDH involvement. Furthermore, any decrease in the level of the low Km mitochondrial aldehyde dehydrogenase activity resulted in a decreased rate of acetaldehyde oxidation showing that its activity governed the rate of acetaldehyde oxidation. These were the same conclusions previously reached using rat liver tissue slices. Thus, it appears that for all mammalian tissue, mitochondria is the primary location of acetaldehyde oxidation.
Cao
Q N
QN
Biochemistry Department, Purdue University, West Lafayette, Indiana 47907.
Tu
G C
GC
Weiner
H
H
D000079:Acetaldehyde / Q000378:metabolism*; D000444:Aldehyde Dehydrogenase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D046508:Culture Techniques; D003484:Cyanamide / Q000494:pharmacology; D004221:Disulfiram / Q000494:pharmacology; D008930:Mitochondria, Liver / Q000201:enzymology*; D013552:Swine
D003484:Cyanamide; D000444:Aldehyde Dehydrogenase; D000079:Acetaldehyde; D004221:Disulfiram