Effects of the Herbicide 2,4,5-Trichlorophenoxyacetic Acid on Growth and Morphology of L 929 Cells

Abstract: A dose-dependent inhibition of growth was found when monolayer cultures of L 929 cells were grown in the presence of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in concentrations from 0.25 to 2.25 mM. At 1.75 and 2.25 mM an almost immediate cessation of growth was found. On removal of the herbicide (2.25 mM) after incubation for 3 or 6 days, cell multiplication was resumed after a lag period of about 24 hours. In the presence of 0.5 to 2.25 mM 2,4,5-T an accumulation of particles in the cytoplasm was observed, and on prolonged incubation in the presence of 2.25 mM 2,4,5-T the cells became rounded and detached from the substratum. By replacing the test medium by the control medium, however, the particles in the cytoplasm disappeared and the cells resumed their fibroblast-like structure.