Chronic ethanol ingestion increases efficiency of oxidative phosphorylation in rat liver mitochondria.
The efficiency of oxidative phosphorylation was compared between rats chronically fed with ethanol and controls. (i) Results showed that the liver mitochondria state 4 respiratory rate was strongly inhibited, while the corresponding proton-motive force was not affected; (ii) the cytochrome oxidase content and activity were decreased and (iii) the oxidative-phosphorylation yield was increased in the ethanol exposed group. Furthermore, oxidative phosphorylation at coupling site II was not affected by ethanol. Cytochrome oxidase inhibition by sodium-azide mimicked the effects of ethanol intoxication in control mitochondria. This indicates that the decrease in cytochrome oxidase activity induced by ethanol intoxication directly increases the efficiency of oxidative phosphorylation.
Piquet
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Laboratoire de Bioénergétique Fondamentale et Appliquée, UJF, P.O. Box 53X, 38041, Grenoble, France.
Nogueira
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V
Devin
A
A
Sibille
B
B
Filippi
C
C
Fontaine
E
E
Roulet
M
M
Rigoulet
M
M
Leverve
X M
XM
D000428:Alcohol Drinking / Q000378:metabolism; D000435:Alcoholic Intoxication / Q000378:metabolism; D000437:Alcoholism / Q000378:metabolism*; D000818:Animals; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D003576:Electron Transport Complex IV / Q000037:antagonists & inhibitors / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D009840:Oligomycins / Q000494:pharmacology; D010085:Oxidative Phosphorylation / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D012402:Rotenone / Q000494:pharmacology; D019810:Sodium Azide / Q000494:pharmacology
D009840:Oligomycins; D012402:Rotenone; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D019810:Sodium Azide; D003576:Electron Transport Complex IV