Serum Triiodothyronine Concentrations in Riboflavin-Deficient, Diabetic and Normal Mice

The riboflavin nutritional status was assessed by activity coefficient (AC) of glutathione reductase in erythrocyte hemolysates of normal Swiss albino (SA) and genetically diabetic (KK) mice aged 8-9 months. 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. The results indicate that the T₃ concentration is not affected either in riboflavin deficiency or in genetic diabetes.