Abstract
Induction of liver glucose-6-phosphate dehydrogenase (G-6-P DH) (E. C. 1. 1. 1. 49) in adult rats was studied under various dietary conditions as follows: group 1) protein free-89% fructose diet; group 2) protein free-89% glucose diet; group 3) 20% casein-69% fructose diet; and group 4) 20% casein- 69% glucose diet. Donryu strain male rats weighing about 200g, which had been fed control diet, were starved for 2 days and then fed the above diet ad lib. Rat liver homogenates were centrifuged at 105, 000 X g for 60 minutes and G-6-P DH activity in the supernatant was measured colorimetrically-Furthermore, G-6-P DH was purified several folds in specific activity by DEAE-cellulose column chromatography, and its electrophoretical behaviour was studied. Induction of G-6-P DH in rat liver was observed in groups 3 and 4, while in groups 1 and 2, no induction was observed. The value of induction was higher in group 3 than in group 4. By polyacrylamide gel disc electrophoresis two distinctbands of G-6-P DH were observed in rats fed either fructose (group 3) or glucose (group 4) with 20% casein, but one of the two bands was obscure in rats fed protein free diet (groups 1 and 2) or in those during starvation.
