Increased hepatic pyruvate dehydrogenase kinase activity in fed hyperthyroid rats: studies in vivo and with cultured hepatocytes. 1996

M C Sugden, and L G Fryer, and D A Priestman, and K A Orfali, and M J Holness
Department of Biochemistry, Queen Mary and Westfield College, (University of London), UK.

Experimental hyperthyroidism induced by the administration of tri-iodothyronine (T3; 100 micrograms/100 g body wt; 3 days) increased plasma non-esterified fatty acids in the fed state in the rat. At the same time, hepatic PDH kinase responded with a persistent (1.6-fold) increase in activity. The exposure of hepatocytes from fed euthyroid rats to T3 (100 nM) in culture for 21 h increased PDH kinase activity to an extent comparable to that observed in vivo in response to hyperthyroidism. The in vitro increase in PDH kinase activity was suppressed by insulin (100 microU/ml) and by inhibition of mitochondrial fatty acid oxidation. The results demonstrate a direct hepatic action of T3 to increase PDH kinase activity, which is mediated by intramitochondrial fatty acyl-CoA or a product of beta-oxidation, and facilitated by hepatic insulin resistance.

UI MeSH Term Description Entries
D006980 Hyperthyroidism Hypersecretion of THYROID HORMONES from the THYROID GLAND. Elevated levels of thyroid hormones increase BASAL METABOLIC RATE. Hyperthyroid,Primary Hyperthyroidism,Hyperthyroidism, Primary,Hyperthyroids
D007328 Insulin A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1). Iletin,Insulin A Chain,Insulin B Chain,Insulin, Regular,Novolin,Sodium Insulin,Soluble Insulin,Chain, Insulin B,Insulin, Sodium,Insulin, Soluble,Regular Insulin
D008099 Liver A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances. Livers
D008928 Mitochondria Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed) Mitochondrial Contraction,Mitochondrion,Contraction, Mitochondrial,Contractions, Mitochondrial,Mitochondrial Contractions
D010084 Oxidation-Reduction A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471). Redox,Oxidation Reduction
D010168 Palmitates Salts and esters of the 16-carbon saturated monocarboxylic acid--palmitic acid. Hexadecanoates,Palmitate
D011494 Protein Kinases A family of enzymes that catalyze the conversion of ATP and a protein to ADP and a phosphoprotein. Protein Kinase,Kinase, Protein,Kinases, Protein
D001786 Blood Glucose Glucose in blood. Blood Sugar,Glucose, Blood,Sugar, Blood
D002334 Carnitine O-Palmitoyltransferase An enzyme that catalyzes reversibly the conversion of palmitoyl-CoA to palmitoylcarnitine in the inner mitochondrial membrane. EC 2.3.1.21. Carnitine Palmitoyltransferase,CPT II,Carnitine Acyltransferase I,Carnitine Palmitoyltransferase I,Carnitine Palmitoyltransferase II,Palmitoylcarnitine Transferase,Palmitylcarnitine Acyltransferase,Acyltransferase I, Carnitine,Acyltransferase, Palmitylcarnitine,Carnitine O Palmitoyltransferase,II, Carnitine Palmitoyltransferase,O-Palmitoyltransferase, Carnitine,Palmitoyltransferase I, Carnitine,Palmitoyltransferase II, Carnitine,Palmitoyltransferase, Carnitine,Transferase, Palmitoylcarnitine
D002478 Cells, Cultured Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others. Cultured Cells,Cell, Cultured,Cultured Cell

Related Publications

M C Sugden, and L G Fryer, and D A Priestman, and K A Orfali, and M J Holness
February 1986, The Biochemical journal,
M C Sugden, and L G Fryer, and D A Priestman, and K A Orfali, and M J Holness
January 1989, The Biochemical journal,
M C Sugden, and L G Fryer, and D A Priestman, and K A Orfali, and M J Holness
August 1987, The Biochemical journal,
M C Sugden, and L G Fryer, and D A Priestman, and K A Orfali, and M J Holness
March 1992, Biochimica et biophysica acta,
M C Sugden, and L G Fryer, and D A Priestman, and K A Orfali, and M J Holness
May 1991, The American journal of physiology,
M C Sugden, and L G Fryer, and D A Priestman, and K A Orfali, and M J Holness
October 2015, European journal of nutrition,
M C Sugden, and L G Fryer, and D A Priestman, and K A Orfali, and M J Holness
February 1997, Biochemical Society transactions,
M C Sugden, and L G Fryer, and D A Priestman, and K A Orfali, and M J Holness
February 1993, The Biochemical journal,
M C Sugden, and L G Fryer, and D A Priestman, and K A Orfali, and M J Holness
January 1975, Biochemical Society transactions,
M C Sugden, and L G Fryer, and D A Priestman, and K A Orfali, and M J Holness
November 1985, The Biochemical journal,
Copied contents to your clipboard!