Hepatic pyruvate dehydrogenase kinase activities during the starved-to-fed transition.
Starvation for 48 h elicited a 74% increase in hepatic pyruvate dehydrogenase (PDH) kinase activity, measured directly by 32Pi-incorporation from [gamma-32P]ATP into a synthetic peptide corresponding to the major phosphorylation site on E1. The administration of chow ad libitum to previously-starved rats suppressed hepatic PDH kinase activity by only approx. 20% within 2 h of re-feeding, and the relatively high activity of PDH kinase was associated with continued suppression of PDC complex re-activation. Whereas there was no further decline in PDH kinase activity over the next 2 h, PDC re-activation to the fed value was observed during this time interval. PDH kinase activity decreased to fed values only after 8 h.
Jones
B S
BS
Department of Biochemistry and Genetics, Medical School, University of Newcastle-upon-Tyne, UK.
Yeaman
S J
SJ
Sugden
M C
MC
Holness
M J
MJ
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D007328:Insulin / Q000097:blood; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013217:Starvation / Q000201:enzymology*
D005230:Fatty Acids, Nonesterified; D007328:Insulin; D011768:Pyruvate Dehydrogenase Complex; D000255:Adenosine Triphosphate