Accumulation of medium chain acyl-CoAs during beta-oxidation of long chain fatty acid by isolated peroxisomes from rat liver.
We have reported fatty alcohol synthesis accompanied by chain elongation in liver peroxisomes (Biochim. Biophys. Acta, 1346, 38 (1997)). In the present experiment, we studied what kind of acyl-CoA(s) destined to be utilized as primer for fatty alcohol synthesis accumulate(s) during peroxisomal beta-oxidation. Peroxisomes were prepared from rat liver treated with clofibrate, a peroxisome proliferator, and incubated with [U-14C]palmitate, in order to investigate acyl-CoAs after beta-oxidation. At 1 mM concentration, MgATP activated beta-oxidation, but inhibited beta-oxidation at concentrations higher than 1 mM. After incubation of peroxisomes with palmitate, various acyl-CoAs were formed. Among medium-chain labelled acyl-CoAs, octanoyl-CoA was mainly detected. These results suggest that octanoyl-CoA accumulates during beta-oxidation of palmitate. When peroxisomes were incubated with [9,10-(3)H]palmitate and [9,10-(3)H]stearate, among medium-chain acyl-CoAs, octanoyl-CoA and decanoyl-CoA were primarily detected, respectively, suggesting the occurrence of at least 4 cycles of beta-oxidation of both fatty acids by peroxisomes.
Hashimoto
F
F
Department of Pathological Biochemistry, Faculty of Pharmaceutical Sciences, Josai University, Sakado, Saitama, Japan.
Furuya
Y
Y
Hayashi
H
H
D000214:Acyl Coenzyme A / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002994:Clofibrate / Q000008:administration & dosage; D004952:Esters; D008099:Liver / Q000648:ultrastructure*; D008297:Male; D010084:Oxidation-Reduction; D019308:Palmitic Acid / Q000378:metabolism; D020675:Peroxisomes / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013229:Stearic Acids / Q000378:metabolism
D000214:Acyl Coenzyme A; D004952:Esters; D013229:Stearic Acids; D019308:Palmitic Acid; C031183:stearic acid; D000255:Adenosine Triphosphate; D002994:Clofibrate