RESUMO
In simplifying the method of determination of activation coefficients (AC) of blood glutathione reductase (BGR), we used saponin solution to prepare blood hemolysate instead of repeated freezing and thawing, thus the time of estimation was shortened. 5, 5'-Dithio-bis-2-nitrobenzoic acid (DTNB) was used to determine the reduced glutathione (GSH), the end product of the NADPH-dependent glutathione reductase reaction on the substrate, oxidized glutathione (GSSG), by means of a photoelectric colorimeter instead of alloxan and an ultra-violet spectrophotometer. From the data obtained in animals and men, the AC values determined by the two methods actually showed no difference.50 male rats, weighing 65-75 grams, were divided from the same litters into 6 groups, namely, the deficient, 2, 5, 10, 30?g and the normal group. The experimental period was 9 weeks. According to the growth weights, the riboflavin contents of urine and liver of the animals, the riboflavin nutritional status of different groups was evaluated. Referring to the corresponding AC values of all groups at the 9th week, the standards of AC values for assessing ribcflavin nutriture could be defined as: 80 severely deficient.
RESUMO
From a study of the experimental riboflavin depletion in rats, it was demonstrated that the activation coefficients (AC) of the blood glutath-ione reductase (BGR) could be used to assess the riboflavin nutritional status of the animal. One week after deficiency the AC values were elevated, while after repletion of riboflavin they returned to normal. The change of AC values appeared sooner than that of daily excretions of riboflavin in urine. So AC value of BGR seemed to be a sensitive index in detecting early riboflavin deficiency. The method of the determination of AC value of BGR was modified so that only 0.02 ml. of whole blood was needed. It is rather convenient when used in field nutritional surveys.
