KETONE-BODY METABOLISM IN THE CARP CYPRINUS-CARPIO - BIOCHEMICAL AND H-1-NMR SPECTROSCOPICAL ANALYSIS

In fed and starved carp, Cyprinus carpio, ketone body metabolism and t hose metabolic and endocrine factors that are known to induce ketogene sis in starving mammals were investigated. Acetoacetate was detected i n plasma and liver of both fed and starved carp. We could not detect S -hydroxybutyrate, neither by H-1-NMR spectroscopy nor by spectrophotom etric assay, in spite of low activities of hepatic 3-hydroxybutyrate d ehydrogenase. Starvation of carp did not create metabolic conditions t hat would favor ketone body synthesis: Mobilization and hepatic catabo lism of fatty acids were only moderately enhanced, the rate of glucone ogenesis was not elevated, and glucagon levels as well as the glucagon /insulin-ratio remained stable or declined. Therefore, the discrepancy in the effect of food deprivation on mammalian and teleostean ketogen esis appears to be caused not by the absence of the ketogenic pathway from teleosts but by major differences between mammals and fish in the ir metabolic response to starvation. Copyright (C) 1997 Elsevier Scien ce Inc.