title: Effects of pyruvate on pyruvate dehydrogenase kinase of rat heart.
abstract: Sensitivity of rat heart pyruvate dehydrogenase kinase (PDHK) to pyruvate inhibition was tested under various conditions using pyruvate dehydrogenase complex (PDC) in mitochondria (mPDC) and in a high speed precipitate of whole tissue homogenates (hPDC). In the latter preparation pyruvate in the range of concentration 1-10 mM caused increasing inhibition of PDHK when the enzyme was prepared from animals fed ad libitum but had no effect when the enzyme was prepared from 48 h starved animals. Similar behaviour was observed in mPDC from fed and starved animals when rotenone was present, pyruvate at 1 mM concentration stimulated PDHK from hearts of fed animals but was without effect at 10 mM. When mPDC or hPDC from hearts of starved animals was incubated at 30 degrees C for 30 min, inhibition of PDHK by pyruvate was restored.
authors.affiliation: Department of Biochemistry, Faculty of Medical Sciences, University of the West Indies, St. Augustine, Trinidad, West Indies.
authors.forename: T C
authors.initials: TC
authors.lastname: Carter
authors.forename: H G
authors.initials: HG
authors.lastname: Coore
mesh_terms: D000818:Animals; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D003999:Dichloroacetic Acid / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008929:Mitochondria, Heart / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology*; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism*; D011773:Pyruvates / Q000378:metabolism*; D019289:Pyruvic Acid; D051381:Rats; D013217:Starvation; D014475:Uncoupling Agents / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D011768:Pyruvate Dehydrogenase Complex; D011773:Pyruvates; D014475:Uncoupling Agents; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D019289:Pyruvic Acid; D003999:Dichloroacetic Acid; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases