INTERACTION OF THE ORGANOCHLORINE PESTICIDE DIELDRIN WITH PHOSPHOLIPID-BILAYERS

Dieldrin is an organochlorine insecticide highly toxic for human being s. Although its exact mechanism of action is not well known, there is evidence that it acts at the cell membrane level. In fact, the lipophi licity of the pesticide as well as that of the phospholipid bilayer pr esent in biological membranes makes the latter a most likely target fo r the interaction of dieldrin with living organisms. In order to evalu ate its perturbing effect upon cell membranes the pesticide was made t o interact with human erythrocytes and molecular models. These studies were performed by scanning electron microscopy on erythrocytes, fluor escence spectroscopy on dimyristoylphosphatidylcholine (DMPC) large un ilamellar vesicles and X-ray diffraction on multilayers of dimirystoyl phosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DM PE). It was observed that dieldrin particularly interacted with DMPC l iposomes and multilayers perturbing its molecular arrangements. Howeve r, no effect was noticed on erythrocytes, which might be due to its hi gh cholesterol content.