Pyruvate dehydrogenase-complex activity in brown adipose tissue of gold thioglucose-obese mice.
The activity of pyruvate dehydrogenase (PDH) complex and PDH kinase were measured in brown adipose tissue (BAT) of 4-week-gold thioglucose (GTG)-obese mice. The proportion of PDH complex in the active dephosphorylated form was 2-fold higher in BAT of post-absorptive obese mice compared with lean controls. This result was consistent with the higher circulating insulin concentration observed in GTG-obese mice. In both obese and lean mice the PDH-complex activity in BAT decreased after 24 h starvation and increased in response to supraphysiological insulin injection, indicating that the PDH complex is insulin-responsive in BAT of GTG-obese mice. There was no difference in the PDH kinase activity of BAT in post-absorptive or insulin-injected lean and obese mice, suggesting that the higher PDH-complex activity in obese mice was not due to decreased PDH kinase activity. There is no evidence for a decreased activity of PDH complex contributing to insulin resistance in BAT of 4-week-GTG-obese mice.
Cooney
G J
GJ
Department of Endocrinology, Royal Prince Alfred Hospital, N.S.W., Australia.
Denyer
G S
GS
Kerbey
A L
AL
Frankland
R L
RL
Blair
S C
SC
Williams
P F
PF
Caterson
I D
ID
D002001:Adipose Tissue, Brown / Q000201:enzymology*; D000818:Animals; D006051:Aurothioglucose; D007328:Insulin / Q000097:blood; D051379:Mice; D008808:Mice, Inbred CBA; D008928:Mitochondria / Q000201:enzymology; D009765:Obesity / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism*
D007328:Insulin; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D011768:Pyruvate Dehydrogenase Complex; D006051:Aurothioglucose; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases