EFFECT OF FASTING ON THE ACTIVITY AND TURNOVER OF RAT-LIVER ALCOHOL-DEHYDROGENASE

被引:29
作者
BOSRON, WF
CRABB, DW
HOUSINGER, TA
LI, TK
机构
[1] INDIANA UNIV, SCH MED, DEPT MED, INDIANAPOLIS, IN 46202 USA
[2] INDIANA UNIV, SCH MED, DEPT BIOCHEM, INDIANAPOLIS, IN 46202 USA
来源
ALCOHOL-CLINICAL AND EXPERIMENTAL RESEARCH | 1984年 / 8卷 / 02期
关键词
D O I
10.1111/j.1530-0277.1984.tb05837.x
中图分类号
R194 [卫生标准、卫生检查、医药管理];
学科分类号
摘要
Alcohol dehydrogenase activity in rat liver decreased with fasting to .apprx. 60% of the fed level, but the specific activities of the enzyme purified from livers of fed and 12 or 48 h 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. The turnover of alcohol dehydrogenase was examined in fed and fasted rats. The fractional rate of enzyme synthesis (ka) 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 h fast. The absolute rate of synthesis (V) and the fractional rate of degradation (kd) were calculated from these ks values, and the total enzyme content in livers from animals that were fasted for 8-72 h. After 48-72 h of fasting, V decreased 16% and kd increased .apprx. 20% with respect to the fed values. These changes accounted for the lowered enzyme activity in the fasted state. The rapid decrease in enzyme activity with fasting, t1/2 .simeq. 16 h, was due to a rapid increase in kd from 0.14-0.16 day-1 in fed animals to 0.61 day-1 during the first 8 h after the initiation of fast. Thereafter, kd decreased steadily to reach 0.18 day-1 after 48-72 h of fasting.
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页码:196 / 200
页数:5
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