Activation of rat liver branched-chain 2-oxo acid dehydrogenase in vivo by glucagon and adrenaline.
The activity of liver branched-chain 2-oxo acid dehydrogenase complex was measured in rats fed on low-protein diets and given adrenaline, glucagon, insulin or dibutyryl cyclic AMP in vivo. Administration of glucagon or adrenaline (200 micrograms/100 g body wt.) resulted in a 4-fold increase in the percentage of active complex. As with glucagon and adrenaline, treatment of rats with cyclic AMP (5 mg/100 g body wt.) resulted in marked activation of branched-chain 2-oxo acid dehydrogenase. Insulin administration (1 unit/100 g body wt.) also resulted in activation of enzyme; however, these effects were less than those observed with glucagon and adrenaline. In contrast with the results obtained with low-protein-fed rats, administration of adrenaline (200 micrograms/100 g body wt.) to rats fed with an adequate amount of protein resulted in only a modest (14%) increase in the activity of the complex. The extent to which these hormones activate branched-chain 2-oxo acid dehydrogenase appears to be correlated with their ability to stimulate amino acid uptake into liver.
D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide); D000818:Animals; D004044:Dietary Proteins / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004837:Epinephrine / Q000494:pharmacology*; D005934:Glucagon / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology; D007658:Ketone Oxidoreductases / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D009097:Multienzyme Complexes / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D004044:Dietary Proteins; D007328:Insulin; D009097:Multienzyme Complexes; D005934:Glucagon; D007658:Ketone Oxidoreductases; D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide); D004837:Epinephrine