Change of choline metabolism in rat liver on chronic ethionine-feeding.
On chronic ethionine-feeding (0.1% DL-ethionine in 0.5% sucrose solution) for 2, 4 or 6 months, choline metabolism in rat hepatic cells was altered considerably, although RNA contents were virtually unchanged. Choline dehydrogenase activity in the hepatic mitochondrial fraction was suppressed by about 1/2 or 1/3, compared to its normal level, whereas choline kinase activity, which existed in the cytoplasmic fraction, was elevated more than 1.5-fold. The normal value for choline-metabolizing enzymes in terms of the choline dehydrogenase/choline kinase activity ratio was estimated to be about 70 under the defined conditions, while the average value of the activity ratio drastically changed to about 10-20 on chronic ethionine-feeding. The present results suggest that an alteration of hepatic choline-flux occurred, due both to an increase in choline kinase activity and to a counteractive decrease in choline dehydrogenase activity.
H
H
Tsuge
N
N
Sato
T
T
Koshiba
Y
Y
Ohashi
Y
Y
Narita
K
K
Takahashi
K
K
Ohashi
D000429:Alcohol Oxidoreductases / Q000378:metabolism; D000818:Animals; D002794:Choline / Q000378:metabolism*; D050545:Choline Dehydrogenase; D002797:Choline Kinase / Q000378:metabolism; D005001:Ethionine / Q000494:pharmacology*; D005260:Female; D008099:Liver / Q000032:analysis / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D011506:Proteins / Q000032:analysis; D012313:RNA / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains
D011506:Proteins; D012313:RNA; D000429:Alcohol Oxidoreductases; D050545:Choline Dehydrogenase; D002797:Choline Kinase; D002794:Choline; D005001:Ethionine