INHIBITION OF CELL-GROWTH BY BAFILOMYCIN A(1), A SELECTIVE INHIBITOR OF VACUOLAR H-ATPASE()

Bafilomycin A(1), a potent selective inhibitor of vacuolar H+-ATPase, inhibited the growth of a variety of cultured cells dose-dependently, including golden hamster embryo and NIH-3T3 fibroblasts, whether or no t they were transformed, and PC12 and HeLa cells. The concentration of bafilomycin A(1) for 50% inhibition of cell growth ranged from 10 to 50 nM. The dose response was nearly parallel with that of the bafilomy cin Al-induced lysosomal pH increase. The degree of pH increase for gr owth inhibition produced by bafilomycin Al was similar to that produce d by NH4Cl in which little difference was recognized in effect among c ell types.