Uptake and phosphorylation of thiamine in rabbit primary proximal tubule cells and Madin Darby Canine Kidney cells. II. Effect of ethanol

Uptake of [¹⁴C]thiamine was studied in renal primary proximal tubule cells and in Madin Darby Canine Kidney cells in culture. Findings were compared with data for the accumulation of [¹⁴C]thiamine and its phosphorylation in renal cortical slices. There was a saturable component for thiamine uptake in all cell types. When normalized for milligrams of protein, renal cortical slices accumulated 82% less ¹⁴C than renal primary proximal tubule cells and 51% less than disal tubule cells. Maximal [¹⁴C]thiamine levels accumulated by the saturable component was 1.33 nmol/g in slices and 7.02 nmol/g in proximal tubule cells. Ethanol, at 25 mM, inhibited thiamine uptake and phosphorylation in the cell cultures similar to its effect in the kidney tissue.