Influence of Certain Sterols and 2:4-Dinitrophenol on Phosphate Accumulation and Distribution in Tetrahymena pyriformis

Abstract

Orthophosphate accumulation by Tetrahymena pyriformis W was enhanced by stigmasterol, B-sitosterol or cholesterol and depressed by 2:4-dinitrophenol (DNP) to an extent determined by the concentration of DNP and hydrogen ion in the suspension medium. The depression of phosphate accumulation by DNP was mitigated by the addition of stigmasterol, the degree of annulment being dependent in part on the stigmasterol concentration. The distribution of accumulated phosphate was not significantly altered by the addition of sterol and/or DNP under the conditions used, indicating that these compounds may influence entry of orthophosphate by affecting a membrane phenomenon.