Abstract
In order to see how ^<35>S-thiamine hydrochloride and thiamine propyldisulfide (TPD) labeled with ^<35>S (inner and outer) would permeate into the cell, they were added to JTC-3 cells in tissue culture and were traced with the lapse of time. As a result, it was found that ^<35>S of thiamine was hardly was incorporated into the cell and remained in the medium. On the other hand, ^<35>S (inner) of TPD was incorporated immediately and continued to permeate into the cell. ^<35>S (outer) of TPD, not similar to the case of red cell, was not incorporated into tissue culture cells at all. The incorporation of ^<35>S (inner) of TPD into those cells cultured in the TPD environment for a long period was somewhat less than that into those cells not previously exposed to TPD. In the presence of a cell, -S-S- bond of TPD was rapidly broken up and thiamine stayed in the cell while the propylmercapto portion was thrown out of the cell. Further study was carried out employing the freezed and thawed cell debris with positive result, but is was trace. Vitamin K_1 had no influence on the reducing action of the cell against TPD.
