Effects of pyruvate on pyruvate dehydrogenase kinase of rat heart.
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.
Carter
T C
TC
Department of Biochemistry, Faculty of Medical Sciences, University of the West Indies, St. Augustine, Trinidad, West Indies.
Coore
H G
HG
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
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