Coenzyme Q releases the inhibitory effect of free fatty acids on mitochondrial glycerophosphate dehydrogenase.
Data presented in this paper show that the size of the endogenous coenzyme Q (CoQ) pool is not a limiting factor in the activation of mitochondrial glycerophosphate-dependent respiration by exogenous CoQ(3), since successive additions of succinate and NADH to brown adipose tissue mitochondria further increase the rate of oxygen uptake. Because the inhibition of glycerophosphate-dependent respiration by oleate was eliminated by added CoQ(3), our data indicate that the activating effect of CoQ(3) is related to the release of the inhibitory effect of endogenous free fatty acids (FFA). Both the inhibitory effect of FFA and the activating effect of CoQ(3) could be demonstrated only for glycerophosphate-dependent respiration, while succinate- or NADH-dependent respiration was not affected. The presented data suggest differences between mitochondrial glycerophosphate dehydrogenase and succinate or NADH dehydrogenases in the transfer of reducing equivalents to the CoQ pool.
Rauchová
Hana
H
Center for Experimental Cardiovascular Research, Czech Academy of Sciences, 142 20 Prague 4, Videnská 1083, Czech Republic.
Drahota
Zdenek
Z
Rauch
Pavel
P
Fato
Romana
R
Lenaz
Giorgio
G
D002001:Adipose Tissue, Brown / Q000378:metabolism; D000818:Animals; D002417:Cattle; D006224:Cricetinae; D045304:Cytochromes c / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005230:Fatty Acids, Nonesterified / Q000378:metabolism*; D005993:Glycerolphosphate Dehydrogenase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005994:Glycerophosphates / Q000378:metabolism; D008297:Male; D008647:Mesocricetus; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology*; D009243:NAD / Q000378:metabolism; D009245:NADH Dehydrogenase / Q000378:metabolism; D019301:Oleic Acid / Q000037:antagonists & inhibitors / Q000494:pharmacology; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D013384:Succinate Cytochrome c Oxidoreductase / Q000378:metabolism; D019802:Succinic Acid / Q000378:metabolism; D014451:Ubiquinone / Q000378:metabolism / Q000494:pharmacology*; D024483:Vitamin K 3 / Q000494:pharmacology
D005230:Fatty Acids, Nonesterified; D005994:Glycerophosphates; D009243:NAD; C028325:ubiquinone Q3; D014451:Ubiquinone; D012710:Serum Albumin, Bovine; D019301:Oleic Acid; C013173:osteum; D024483:Vitamin K 3; D045304:Cytochromes c; D019802:Succinic Acid; D013384:Succinate Cytochrome c Oxidoreductase; D005993:Glycerolphosphate Dehydrogenase; D009245:NADH Dehydrogenase