The activity of glucose‐6‐phosphate dehydrogenase in mouse liver is induced nearly 10‐fold and the activity of citrate lyase nearly 6‐fold, when C57BL mice are transferred from a diet containing 25% corn oil to a fatless diet. When the mice on the fatless diet are transferred back to the high‐fat diet, both enzymes return to their basal level with half‐lives of 41 and 55 h, respectively. Malate‐NADP dehydrogenase and 6‐phosphogluconate dehydrogenase are induced and repressed in parallel, but to a lesser extent. In addition to the induction‐repression cycle, all four enzymes also undergo diurnal variations involving 50%, changes in their activities. Glucose‐6‐phosphate dehydrogenase is induced to a certain extent also in adipose tissue, but not in several other mouse tissues. The induction cycle can be repeated in liver at least three times successively. Glucose‐6‐phosphate dehydrogenase induction takes place in the bulk of parenchymal liver cells and not in a selected population. Actinomycin D and cycloheximide administration prevents the induction of the enzymes, but it is not clear whether a direct effect on the enzyme‐synthesizing machinery is involved.
|Number of pages
|European Journal of Biochemistry
|Published - Jun 1974