Oxidation of cis-5-unsaturated fatty acids in intact rat liver mitochondria: the operation of reduction pathways.
The metabolism of cis-5 unsaturated fatty acids was studied in intact rat liver mitochondria to assess the operation of a reduction pathway. By using direct quantification of metabolites with a capillary-column gas chromatography, 3-hydroxydodecanoate was identified among other metabolites when cis-5-dodecenoate was metabolized in intact rat liver mitochondria. The formation of 3-hydroxydodecanoate supports the existence of a reduction pathway in the metabolism of cis-5-unsaturated fatty acids. This metabolite cannot be produced from the conventional isomerase-mediated pathway. However, the data also indicated the possible operation of the conventional isomerase-mediated pathway in intact rat liver mitochondria. The reduction pathway appears to account for at least 61% of the pathway for cis-5-dodecenoate. This reduction pathway was likely to proceed from the dehydrogenation to trans-2,cis-5-dodecadienoyl-CoA, which was isomerized to delta 3, delta 5-dodecadienoyl-CoA, then to trans-2,trans-4-dodecadienoate. The reduction was mediated by 2,4-dienoyl-CoA reductase by the conversion of trans-2,trans-4-dodecadienoyl-CoA into trans-3-dodecenoyl-CoA. However, direct reduction of the cis-5 double bond was also shown to be operating, although to a lesser extent.
Tserng
K Y
KY
Medical Research Service, VA Medical Center, Cleveland, OH, USA.
Jin
S J
SJ
D000818:Animals; D005229:Fatty Acids, Monounsaturated / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D066298:In Vitro Techniques; D008930:Mitochondria, Liver / Q000378:metabolism*; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D051381:Rats; D017207:Rats, Sprague-Dawley
D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated; C078125:5-dodecenoic acid; D009249:NADP