Abstract
The riboflavin nutritional status was assesed by the activity coefficient (AC) of glutathione reductase in erythrocyte hemolysates of normal Swiss albino (SA) and genetically diabetic (KK) mice aged 8-9 mo. AC values greater than 1.3 were considered as evidence of riboflavin deficiency. Based upon AC values, both SA and KK mice were divided into normal and riboflavin-deficient groups. In some young SA mice, riboflavin deficiency was produced by feeding of a riboflavin-deficient diet. In both normal and riboflavin-deficient mice, the serum L-triiodothyronine (T3) concentrations were determined by radioimmunoassay. Th T3 concentration is not affected either in riboflavin deficiency or in genetic diabetes.