Hepatic branched-chain alpha-keto acid dehydrogenase complex in female rats: activation by exercise and starvation.
The effects of acute exercise and starvation on hepatic branched-chain alpha-keto acid dehydrogenase (BCKDH) complex activity were examined in female rats fed high (30%)- or low (8%)-protein diets. The total activity of the complex was significantly higher in the high protein-fed rats than in the low protein-fed rats but was not affected by acute exercise and starvation in either diet group. The proportion of the active form of BCKDH complex was less than 10% in both diet groups. Acute exercise and starvation markedly increased the active form of the complex in both diet groups. The activity of BCKDH kinase, which is responsible for inactivation of the BCKDH complex by phosphorylation, tended to be decreased by acute exercise and starvation in both diet groups. These results suggest that the activity of the BCKDH kinase is an important factor determining the proportion of the active form of BCKDH complex in exercise and starvation, and that the female rat is a useful model for studying the regulation of hepatic BCKDH complex activity.
Kobayashi
R
R
Department of Nutrition and Food Science, Ochanomizu University, Tokyo, Japan.
Shimomura
Y
Y
Murakami
T
T
Nakai
N
N
Otsuka
M
M
Arakawa
N
N
Shimizu
K
K
Harris
R A
RA
D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide); D000818:Animals; D018753:Diet, Protein-Restricted; D004044:Dietary Proteins / Q000008:administration & dosage; D004789:Enzyme Activation; D005260:Female; D007651:Keto Acids / Q000097:blood; D007658:Ketone Oxidoreductases / Q000378:metabolism*; D008099:Liver / Q000201:enzymology*; D009097:Multienzyme Complexes / Q000378:metabolism*; D005082:Physical Exertion / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013217:Starvation
D004044:Dietary Proteins; D007651:Keto Acids; D009097:Multienzyme Complexes; C013082:alpha-ketoisocaproic acid; D007658:Ketone Oxidoreductases; D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)