Effect of Fasting on the Activity and Turnover of Rat Liver Alcohol Dehydrogenase

William F. Bosron, David W. Crabb, Terry A. Housinger, Ting‐Kai ‐K Li

Research output: Contribution to journalArticle

30 Scopus citations

Abstract

Alcohol dehydrogenase activity in rat liver decreased with fasting to about 60% of the fed level, but the specific activities of the enzyme purified from livers of fed and 12- or 48-hr fasted animals were similar, 3.2-3.4 U/mg protein. Therefore, the decrease in enzyme activity with fasting should have resulted from a decrease in the amount of enzyme protein. Accordingly, the turnover of alcohol dehydrogenase was examined in fed and fasted rats. The fractional rate of enzyme synthesis (k(s)) in fed rats was determined by radioisotopic methods to be 0.13 day-1 and it increased to 0.18 day-1 after a 12- or 48-hr fast. The absolute rate of synthesis (V) and the fractional rate of degradation (k(d)) were calculated from these k(s) values and the total enzyme content in livers from animals that were fasted for 8 to 72 hr. After 48-72 hr of fasting, V decreased 16% and k(d) increased about 20% with respect to the fed values. Together, these changes accounted for the lowered enzyme activity in the fasted state. The rapid decrease in enzyme activity with fasting, t( 1/2 ) ≃ 16 hr, was found to be due to a rapid increase in k(d) from 0.14-0.16 day-1 in fed animals to 0.61 day-1 during the first 8 hr after the initiation of fast. Thereafter, k(d) decreased steadily to reach 0.18 day-1 after 48-72 hr of fasting.

Original languageEnglish (US)
Pages (from-to)196-200
Number of pages5
JournalAlcoholism: Clinical and Experimental Research
Volume8
Issue number2
DOIs
StatePublished - Mar 1984

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Toxicology
  • Psychiatry and Mental health

Fingerprint Dive into the research topics of 'Effect of Fasting on the Activity and Turnover of Rat Liver Alcohol Dehydrogenase'. Together they form a unique fingerprint.

  • Cite this