Ketogenesis in mitochondria isolated from liver biopsies of normal and starved dogs: comparison with rat-liver mitochondria.
Fatty acid oxidation and ketogenesis were studied in isolated dog-liver mitochondria in order to investigate whether the absence of hyperketonemia in fasting dogs results from a low capacity of hepatic ketogenesis. Isolated rat-liver mitochondria were used as reference. The results indicate that: (a) Dog-liver mitochondria oxidize long-chain fatty acids and produce ketone bodies at about equal rates as rat-liver mitochondria. No differences were detected in the regulation of ketogenesis. (b) Rates of oxidation of medium-chain fatty acids are significantly lower in dog-liver mitochondria than in rat-liver mitochondria. (c) Fasting does not influence the capacity of liver mitochondria for fatty acid oxidation but their ketogenic capacity is slightly enhanced in both species. The regulation of the energy metabolism in the fasting dog is discussed and compared with that in other mammalian species.
D000818:Animals; D004285:Dogs; D005260:Female; D066298:In Vitro Techniques; D007659:Ketones / Q000096:biosynthesis*; D008930:Mitochondria, Liver / Q000378:metabolism*; D010084:Oxidation-Reduction; D010168:Palmitates / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity; D013217:Starvation / Q000378:metabolism*
D007659:Ketones; D010168:Palmitates