栄養素組成と体蛋白質の代謝

(第1報)蛋白質含量とXanthine Oxidase Activity

抄録

Relation between the amounts of dietary protein and enzyme activity was examined by using arbino rats. Casein fed as the source of proiein at levels of 0, 15, 30, 40, 60 and 80 per cent in the diet for eighteen days. Liver xanthine oxidase which is considered to be relate with the metabolism of nuclepprotein was chosen for the enzyme of this experiment.
The enzyme activity was measured by a modification of manometric method of AXELROD-ELVEHJEM and colorimetric `method of LITWACK et al. A corelation has been found between these methods.
The results showed that the enzyme respons was very sensitive to changes in the content of protein in diets and depleted to “zero” levels at the protein free ration (Table 2).
From the values of enzyme activity which was plotted aganist the level of dietary protein (casein) fed, we found that xanthine oxidase activity was increased according to the amount of protein, but no change took place in greater amount than about 30 per cent protein in diet (Fig. 2).
The authors suggested that feeding of dietary protein which maintained the stationary level of xanthine oxidase activity was required.