Changes in protein synthesis in rat liver during the administration of the thiamine deficient diet.

Abstract

Listen

Translate article

1. Rats fed on thiamine-deficient diet showed a slight increase in body weight for the first two weeks but the body weight decreased thereafter. 2. Wet weight of the liver tissue from the thiamine-deficient rats increased slightly during the first 18 days, but after they remained constant. 3. The most of the thiamine which was found in cytoplasm of the liver cell was decreased rapidly as the result of deprivation of thiamine in the diet. 4. In polysomal pattern which was analyzed by sucrose gradient centrifugation, heavy polysomes tended to increase after 7 days of thiamine deficiency and incorporation of 3H-orotic acid also increased in the polymer portion which were larger than trimer. After 25 to 31 days of thiamine deficiency, heavy polysomes decreased and light polysomes increased markedly. The Ratio of polysomes which is heavier than hexamer to the total polysome showed a transitory increase after 7 days of thiamine deficiency but decreased thereafter. 5. Specific activity of 3H-orotic acid incorporated into polysomal RNA in vivo and that of 14 C-leucine incorporated into polysome in vitro also showed a transitory increase after 7 days of deficiency and then decreased thereafter. Both recovered rapidly by the administration of thiamine.