title: Effect of thyroid state on ketogenic capacity of the isolated perfused liver of starved rats.
abstract: The effect of different thyroid states on the oxidation of free fatty acids was investigated in the isolated perfused liver of 24-h-starved rats. 1. Compared with the euthyroid control the oxidation of oleate to ketone bodies as well as to CO2 was increased in hyper-, while it was unchanged in hypothyroid livers. 2. The addition of carnitine stimulated oleate oxidation in livers from eu- and hyperthyroid rats, but was without effect in hypothyroid livers. 3. Glucose did not affect the thyroid hormone-mediated effect of oleate conversion to ketone bodies. 4. Hepatic oxidation of octanoate was similar in all thyroid states. 5. Re-esterification of oleate was enhanced in hypo-, but reduced in hyperthyroidism. 6. The concentration of hepatic malonyl-CoA was decreased in hypo- and unchanged in hyperthyroid livers. 7. The concentration of cyclic AMP was elevated in the liver of hyperthyroid rats, no differences were observed between eu- and hypothyroid livers. However, increasing the hepatic cyclic AMP content by the addition of glucagon did not stimulate ketogenesis in eu- and hypothyroid livers. 8. The results indicate that thyroid hormones stimulate oleate oxidation by an accelerated transport of its CoA derivative into the mitochondrial compartment.
mesh_terms: D000227:Adenine Nucleotides / Q000378:metabolism; D000818:Animals; D000242:Cyclic AMP / Q000494:pharmacology; D005934:Glucagon / Q000494:pharmacology; D006980:Hyperthyroidism / Q000378:metabolism*; D007037:Hypothyroidism / Q000378:metabolism*; D007657:Ketone Bodies / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008297:Male; D019301:Oleic Acid; D009829:Oleic Acids / Q000378:metabolism; D010101:Oxygen Consumption; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D013217:Starvation; D013961:Thyroid Gland / Q000502:physiology*
chemical_list: D000227:Adenine Nucleotides; D007657:Ketone Bodies; D009829:Oleic Acids; D019301:Oleic Acid; D005934:Glucagon; D000242:Cyclic AMP