Abstract
Metabolic conversion of thiamine-S-sulfonate (B_1SSO_3H) to the thiol form (thiamine) in the rabbit and rat was studied in comparison with those of thiamine disulfide (TDS) and cysteine-S-sulfonate (CySSO_3H). Intravenously administered B_1SSO_3H gave lower blood level of thiamine than TDS did. Blood cystine levels after the administration of CySSO_3H and CySH were almost the same. In the rat, the amounts of unchanged B_1SSO_3H, TDS and CySSO_3H excreted in the urine were 36,13 and 0%, respectively, of the intravenous doses. The brain, heart, liver, kidney, small intestine and blood of the rat were found to metabolize B_1SSO_3H and CySSO_3H in vitro. The above results suggest that B_1SSO_3H, like in case of TDS and CySSO_3H, was converted to the thiol form (thiamine), and that the conversion rate was the lowest of the three.
