Inhibition of the oxidation of acetaldehyde and formaldehyde by hepatocytes and mitochondria by crotonaldehyde

Dicker, E; Cederbaum, AI

HERO ID

1578983

Reference Type

Journal Article

Year

1984

Language

English

PMID

6486817

HERO ID 1578983
In Press No
Year 1984
Title Inhibition of the oxidation of acetaldehyde and formaldehyde by hepatocytes and mitochondria by crotonaldehyde
Authors Dicker, E; Cederbaum, AI
Journal Archives of Biochemistry and Biophysics
Volume 234
Issue 1
Page Numbers 187-196
Abstract Crotonaldehyde was oxidized by disrupted rat liver mitochondrial fractions or by intact mitochondria at rates that were only 10 to 15% that of acetaldehyde. Although a poor substrate for oxidation, crotonaldehyde is an effective inhibitor of the oxidation of acetaldehyde by mitochondrial aldehyde dehydrogenase, by intact mitochondria, and by isolated hepatocytes. Inhibition by crotonaldehyde was competitive with respect to acetaldehyde, and the Ki for crotonaldehyde was about 5 to 20 microM. Crotonaldehyde had no effect on the oxidation of glutamate or succinate. Very low levels of acetaldehyde were detected during the metabolism of ethanol. Crotonaldehyde increased the accumulation of acetaldehyde more than 10-fold, indicating that crotonaldehyde, besides inhibiting the oxidation of added acetaldehyde, also inhibited the oxidation of acetaldehyde generated by the metabolism of ethanol. Formaldehyde was a substrate for the low-Km mitochondrial aldehyde dehydrogenase, as well as for a cytosolic, glutathione-dependent formaldehyde dehydrogenase. Crotonaldehyde was a potent inhibitor of mitochondrial oxidation of formaldehyde, but had no effect on the activity of formaldehyde dehydrogenase. In hepatocytes, crotonaldehyde produced about 30 to 40% inhibition of formaldehyde oxidation, which was similar to the inhibition produced by cyanamide. This suggested that part of the formaldehyde oxidation occurred via the mitochondrial aldehyde dehydrogenase, and part via formaldehyde dehydrogenase. The fact that inhibition by crotonaldehyde is competitive may be of value since other commonly used inhibitors of aldehyde dehydrogenase are irreversible inhibitors of the enzyme.
Doi 10.1016/0003-9861(84)90340-0
Pmid 6486817
Wosid WOS:A1984TN05200024
Url <Go to ISI>://WOS:A1984TN05200024
Is Certified Translation No
Dupe Override No
Comments Source: Web of Science WOS:A1984TN05200024
Is Public Yes
Language Text English