The long range goal of this research is to investigate the mechanism of embryotoxicity, teratogenicity and neonatal toxicity of various pesticide agents. Correlations will be sought between toxic effects of the test agents ranging from gross morphologic defects to subtle biochemical and behavioral anomalies and specific biochemical abnormalities. Pesticide agents representative of several classes of compounds will be administered to timed pregnant mice and rats at various stages of gestation. Morphologic development will be assessed by examination of cesarean delivered fetuses. In other experiments neonatal development will be followed by regular measurements of growth, morbidity, mortality and development of motor function. For all compounds studied the importance of transient inhibition or stimulation of protein or nucleic acid synthesis will be determined. Where specific biochemical actions are known, such as cholinesterase inhibition by organophosphates, alterations in these parameters will be measured. In addition, the pharmacodynamic and/or toxicodynamic properties of each chemical will be determined and related to the particular perinatal toxicity of each. Collectively, these studies are intended to fill the gap in our knowledge of chemical induced birth defects and postnatal toxicity on one hand and normal biochemical processes of development on the other. Another aspect of these studies is to consider the possible interaction of drugs and environmental factors with pesticide agents which may modify the teratogenic or toxic effects.