INTERACTION OF 2,4-DICHLOROPHENOXYACETIC ACID (2,4-D) WITH CELL AND MODEL MEMBRANES

2,4-dichlorophenoxyacetic acid (2,4-D), a widely used herbicide, is a component of the 'agent orange' whose toxicity has been extensively st udied without definite conclusions. In order to evaluate its perturbin g effect upon cell membranes, 2,4-D was made to interact with human er ythrocytes and molecular models. These studies were performed by scann ing electron microscopy on red cells, fluorescence spectroscopy on dim yristoylphosphatidylcholine (DMPC) large unilamellar vesicles and X-ra y diffraction on multilayers of DMPC and dimyristoylphosphatidylethand lamine (DMPE). It was observed that 2,4-D induced a pronounced shape c hange to the erythrocytes. This effect is explained by the herbicide i nteraction with the outer monolayer of the red cell membrane.