Ultrastructural effects of DDT, DDD, and DDE on neural cells of the chicken embryo model

Human exposure to environmental compounds with estrogenic activity and the potential effects on human health is the subject of ongoing scientific debates. Their potential effects raise concern regarding neurological development after prenatal exposure. Central to this debate is the pesticide 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT). Although it has apparent low acute toxicity in mammals, DDT has a long residual persistence and laboratory research has indicated that it acts on the CNS by interfering with Na+/K+ pump mechanism of the neuronal membranes, causing disruption in Ca2+ homeostasis. Potentially this may lead to both apoptosis and necrosis. The present study investigates the effects of DDT and two of its metabolites DDD and DDE on the ultramorphology of neural cells, using a previously published chicken embryo model. Results indicate cellular swelling, budding, and increased membrane permeability for all three chemicals, accompanied by karyolysis in the DDE group (typical features of oncosis). These results support the finding of other researchers as well as the concerns of the WHO that DDT and its metabolites may cause neurotoxicity after prenatal exposure. (c) 2007 Wiley Periodicals, Inc.