Toxicology and applied pharmacology
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Toxicol. Appl. Pharmacol. · Jun 1999
Comparative StudyComparison of aldicarb and methamidophos neurotoxicity at different ages in the rat: behavioral and biochemical parameters.
Young organisms are often more sensitive to the toxic effects of pesticides, and this finding has spurred research on further characterization of this susceptibility. The neurotoxic effects of cholinesterase (ChE)-inhibiting pesticides are of particular concern for human health risk assessment due to the widespread exposure potential in children. This study evaluated age-related differences in susceptibility for a carbamate (aldicarb) and an organophosphorus pesticide (methamidophos). ⋯ Aldicarb-induced ChE inhibition was readily reversible in all age groups, whereas with methamidophos, enzyme activity recovered more rapidly in the young. Most behavioral alterations had recovered by 24 h with either pesticide. The results of these studies indicate that (1) ChE-inhibiting pesticides are not all the same regarding relative sensitivity of the young; (2) age-related differences were reflected in both the MTDs and degree of ChE inhibition; and (3) age-related differences in neurobehavioral measures depended on the pesticide and on the end points examined.