Branched-chain alpha-ketoacids and related acids in thiamin-deprived rats.
We showed elevated plasma levels of branched-chain amino acids, alpha-ketoacids, alpha-hydroxyacids in thiamin-deprived rats, which had decreased liver thiamin levels (2.4% of control) after 4 weeks of feeding of thiamin-deficient diet. The ratios of mean levels of these acids in thiamin-deficient rats to those in control rats were as follows: total branched-chain amino acids 1.6; total branched-chain alpha-ketoacids 2.7; total branched-chain alpha-hydroxyacids 3.6; pyruvic acid 1.6. The plasma level of total branched-chain alpha-hydroxyacids was correlated to liver thiamin concentration (r = -0.67, p less than 0.01), but those of the other two acids were not correlated. Although the increased levels of branched-chain acids in thiamin-deprived rats were less remarkable than those of ill patients with maple syrup urine disease, they reflect the reportedly decreased branched-chain alpha-ketoacid dehydrogenase activities (about 40% of control), and we discussed whether the toxic effects of individual branched-chain acid could be demonstrated by its administration to the thiamin-deprived rats.
Shigematsu
Y
Y
Department of Pediatrics, Fukui Medical School, Japan.
Kikawa
Y
Y
Sudo
M
M
Itokawa
Y
Y
D000597:Amino Acids, Branched-Chain / Q000097:blood*; D000818:Animals; D006880:Hydroxy Acids / Q000097:blood*; D007651:Keto Acids / Q000097:blood*; D008099:Liver / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013831:Thiamine / Q000378:metabolism; D013832:Thiamine Deficiency / Q000097:blood*
D000597:Amino Acids, Branched-Chain; D006880:Hydroxy Acids; D007651:Keto Acids; D013831:Thiamine