Effect of Acute Exposure to Malathion and Lead on

Authors: R R Holem William A Hopkins Larry G Talent

Publish Date: 2006/02/07

Volume: 51, Issue: 1, Pages: 111-116

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Abstract

There are few ecotoxicological studies involving reptiles despite the fact that anthropogenic pollutants have been identified as a major threat to reptile populations worldwide Particularly lacking are effectsbased studies in reptiles exposed to known concentrations of contaminants We hypothesized that acute exposure to neurotoxic metals and pesticides could influence locomotor performance of reptiles To test this hypothesis we exposed western fence lizards Sceloporus occidentalis to two common and widely studied neurotoxic contaminants malathion and lead Pb Single doses were administered via oral gavage at orderofmagnitude levels ranging from 02 to 200 and 10 to 1000 mg/kg body weight basis for malathion and Pb respectively Lizard sprint velocity was determined using a 23m sprint track interfaced with a laptop computer 24 hrs prior to dosing and again at 4 24 120 and 312 hrs postdose Twenty percent and 30 mortality occurred at the highest malathion and Pb dose levels 200 and 1000 mg/kg and 70 of the lizards exposed to 200 mg/kg malathion exhibited clinical symptoms of organophosphate poisoning Contrary to our predictions exposure to Pb had no effect on locomotor performance and exposure to the highest concentration of malathion increased sprint velocity Based on the fact that the lower and most ecologically relevant concentrations of Pb and malathion had no effect on sprint velocity we suggest that other performance parameters that require fine locomotor skills eg climbing ability may be more sensitive metrics of acute neurotoxicity and warrant further studySarah DuRant provided technical support on the project Jason Unrine John Willson and Chris Winne reviewed an early draft of the manuscript Animal husbandry was in conformance with all appropriate animal care and use protocols Financial support was provided by the Environmental Remediation Sciences Division of the Office of Biological and Environmental Research US Department of Energy through the Financial Assistance Award DEFC0996SR18546 to the University of Georgia Research Foundation Additional support to RRH was provided by a research assistantship from the University of Georgia’s Interdisciplinary Toxicology Program

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