The factors which regulate soluble and particulate glucokinase and hexokinase activity in the liver of domestic chickens has been investigated. Pretreatment with oral administration (via tube feeding) of glucose plus injection of insulin resulted in a significant increase in the activity of soluble (p <0.01) and particulate (p <0.01) glucokinase activity whereas fasting for 48 hours reduced glucokinase and hexokinase activity (p <0.01) in the particulate fraction only. Treatment of fed chickens for 2 weeks with thyroxine (50 ug: i.m. daily) plus triiodothyronine (50 ug) resulted in a marginal decrease (NS) in soluble glucokinase activity but significantly increased soluble hexokinase (p <0.05) activity. Thyroidectomized animals showed a decline in both soluble glucokinase (p <0.01) and hexokinase (p <0.025) activity. There was no effect of thyroid hormone manipulation on particulate glucokinase activity although there was a significant reduction in particulate hexokinase activity (p < 0.05) in thyroidectomized birds. These data establish a physiological role for the glucokinase enzyme activity in avian carbohydrate metabolism and suggest that in contrast with the mammal, the particulate fraction is the more physiologically important enzyme.
|Original language||English (US)|
|Number of pages||8|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Sep 30 1986|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology