title: Critical consideration of the multiplicity of experimental and organismic determinants of pyrethroid neurotoxicity: a proof of concept.
abstract: Pyrethroids (PYR) are pesticides with high insecticidal activity that may disrupt neuronal excitability in target and nontarget species. The accumulated evidence consistently showed that this neurophysiologic action is followed by alterations in motor, sensorimotor, neuromuscular, and thermoregulatory responses. Nevertheless, there are some equivocal results regarding the potency of PYR in lab animals. The estimation of potency is an important step in pesticide chemical risk assessment. In order to identify the variables influencing neurobehavioral findings across PYR studies, evidence on experimental and organismic determinants of acute PYR-induced neurotoxicity was reviewed in rodents. A comprehensive analysis of these studies was conducted focusing on test material and dosing conditions, testing conditions, animal models, and other determinants such as testing room temperature. Variations in the severity of the neurotoxicity, under lab-controlled conditions, was explained based upon factors including influence of animal species and age, test material features such as chemical structure and stereochemistry, and dosing conditions such as vehicle, route of exposure, and dose volume. If not controlled, the interplay of these factors may lead to large variance in potency estimation. This review examined the scope of acute toxicological data required to determine the safety of pesticide products, and factors and covariates that need to be controlled in order to ensure that predictivity and precaution are balanced in a risk assessment process within a reasonable time-frame, using acute PYR-induced neurotoxicity in rodents as an exemplar.
authors.affiliation: a Laboratorio de Toxicología de Mezclas Químicas, Instituto de Investigación IQUIBICEN, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento Química Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires, Ciudad Universitaria UBA, Ciudad Autónoma de Buenos Aires , Argentina.
authors.forename: M J
authors.initials: MJ
authors.lastname: Wolansky
authors.forename: R
authors.initials: R
authors.lastname: Tornero-Velez
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods*; D020258:Neurotoxicity Syndromes / Q000209:etiology* / Q000517:prevention & control; D011722:Pyrethrins / Q000633:toxicity*
chemical_list: D011722:Pyrethrins