Relevance of developmental testing of exposure to methamidophos during gestation to its toxicology evaluation

Abstract

The organophosphate insecticide (OP) are known to be able to promote cholinergic toxicity related to neurobehavioral findings. The measures of cholinesterase activity are the most common index of its action. The influence was evaluated, of the OP methamidophos (1.0 mg/kg), by oral exposure during gestational organogenesis of rats, on maturational and behavioral aspects of offspring development. This dose did not promote evidence of maternal toxicity. The pesticide did not affect body weight gain of the dams and offspring, but interfered with the offspring's physical and maturational development landmarks according to age. The behavioral performance of the offspring with or without a pharmacological challenge was tested at different postnatal days (pnd 14, 21 and 40) in an open-field apparatus. The results showed a large standard deviation that prejudiced the conclusions. There were no observed alterations in the swimming behavior tested also at pnd 7, 14 and 21. As long as the obtained results showed some subtle effects on rat development, the data, as possible additional effect biomarkers for risk analysis, will aid further studies of the embryo-feto-toxic potential of OP exposure.