Effects of riboflavin deficiency and clofibrate treatment on the five acyl-CoA dehydrogenases in rat liver mitochondria.
Rats were maintained on a riboflavin-deficient diet or on a diet containing clofibrate (0.5%, w/w). The activities of the mitochondrial FAD-dependent straight-chain acyl-CoA dehydrogenases (butyryl-CoA, octanoyl-CoA and palmitoyl-CoA) and the branched-chain acyl-CoA dehydrogenases (isovaleryl-CoA and isobutyryl-CoA) involved in the degradation of branched-chain acyl-CoA esters derived from branched-chain amino acids were assayed in liver mitochondrial extracts prepared in the absence and presence of exogenous FAD. These activities were low in livers from riboflavin-deficient rats (11, 28, 16, 6 and less than 2% of controls respectively) when prepared in the absence of exogenous FAD, and were not restored to control values when prepared in 25 microM-FAD (29, 47, 28, 7 and 17%). Clofibrate feeding increased the activities of butyryl-CoA, octanoyl-CoA and palmitoyl-CoA dehydrogenases (by 48, 116 and 98% of controls respectively), but not, by contrast, the activities of isovaleryl-CoA and isobutyryl-CoA dehydrogenases (62 and 102% of controls respectively). The mitochondrial fractions from riboflavin-deficient and from clofibrate-fed rats oxidized palmitoylcarnitine in State 3 at rates of 32 and 163% respectively of those from control rats.
Veitch
K
K
Laboratoire de Chimie Physiologique, I.C.P., Brussels, Belgium.
Draye
J P
JP
Van Hoof
F
F
Sherratt
H S
HS
D000818:Animals; D002994:Clofibrate / Q000494:pharmacology*; D044943:Fatty Acid Desaturases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005182:Flavin-Adenine Dinucleotide / Q000494:pharmacology; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects / Q000201:enzymology*; D010084:Oxidation-Reduction; D010172:Palmitoylcarnitine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012257:Riboflavin Deficiency / Q000201:enzymology*
D007527:Isoenzymes; D005182:Flavin-Adenine Dinucleotide; D010172:Palmitoylcarnitine; D044943:Fatty Acid Desaturases; D002994:Clofibrate