Abstract
Effects of thiamine (B_1) administration on glucose intolerance and bradycardia of B_1-deficient rats were investigated. Glucose intolerance was cured by B_1-HNO_3 administration of higher dose than 0.05 mg/kg, when a B_1-deficient diet containing all vitamins other than B_1 was further given after the B_1-administration. The effect of B_1 on glucose intolerance was significantly diminished when a all vitamins free diet in place of B_1-deficient diet was used after the B_1-administration. On the other hand, the restoration of bradycardia by B_1 was observed when either B_1-deficient diet or all vitamins free diet was given after B_1-administration. In addition, when pyridoxine・HC1 (0.2 mg/kg) and hydroxycobalamin acetate (0.002 mg/kg) were simultaneously added to B_1 (0.02 mg/kg) injection, the restorative effect on glucose intolerance but not on bradycardia were seen. These results suggest that bradycardia is a specific sign for B_1-deficiency in the rat but glucose intolerance is resulted from a nutritional disturbance in which vitamins other besides B_1 are also lacking.
