Modulation of branched-chain amino acid oxidation in rat hemidiaphragms in vitro by glucose and ketone bodies.
Branched-chain amino acid metabolism in hemidiaphragms from 40 h-starved rats is influenced by the provision of glucose as co-substrate. Glucose inhibits 14CO2 production from [l-14C]valine and [U-14C]valine but stimulates 14CO2 production from [l-14C]leucine, [U-14C]leucine and [U-14C]isoleucine. In the presence of glucose, ketone bodies inhibit alanine release and 14CO2 production from [l-14C]valine, [l-14C]leucine and [U-14C]isoleucine, but inhibition is not observed in the absence of glucose as cosubstrate. Glucose-dependent inhibition by ketone bodies of branched-chain amino acid oxidation via inhibition of the branched-chain 2-oxo acid dehydrogenase complex or branched-chain amino acid aminotransferase may account in part for the reported hypoalanaemic action of ketone bodies in vivo.
D020155:3-Hydroxybutyric Acid; D000090:Acetoacetates / Q000494:pharmacology*; D000597:Amino Acids, Branched-Chain / Q000378:metabolism*; D000818:Animals; D002250:Carbon Radioisotopes; D003964:Diaphragm / Q000187:drug effects / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology*; D006885:Hydroxybutyrates / Q000494:pharmacology*; D007532:Isoleucine / Q000378:metabolism; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014633:Valine / Q000378:metabolism
D000090:Acetoacetates; D000597:Amino Acids, Branched-Chain; D002250:Carbon Radioisotopes; D006885:Hydroxybutyrates; D007532:Isoleucine; C016635:acetoacetic acid; D007930:Leucine; D014633:Valine; D005947:Glucose; D020155:3-Hydroxybutyric Acid