You are here:
PHARMACOKINETIC DIFFERENCES MAY EXPLAIN THE AGE-RELATED SENSITIVITY OF DELTAMETHRIN, A PYRETHROID INSECTICIDE, IN RATS.
Citation:
Haines, W. T., R S. Marshall, D L. Hunter, AND S J. Padilla. PHARMACOKINETIC DIFFERENCES MAY EXPLAIN THE AGE-RELATED SENSITIVITY OF DELTAMETHRIN, A PYRETHROID INSECTICIDE, IN RATS. Presented at Society of Toxicology, Baltimore, MD, March 21-25, 2004.
Description:
This study was designed to examine the age-related sensitivity to the pyrethroid insecticide, deltamethrin [(S)- -cyano-3-phenoxybenzyl (1R,3R)-3-(2,2-dibromomovinyl)2,2-dimethylcyclopropanecarboxylate], in Long Evans, hooded, male rats. Deltamethrin has been shown to be more acutely toxic to weanling (21 days) rats (Sheets et al., Toxicol Appl. Pharmacol., 1994) than adults. Our hypothesis is that weanling rats are more sensitive than adults to deltamethrin due to pharmacokinetic differences. Therefore, we conducted time course studies in both weanling (PND 21) and adult (PND 90) male rats to determine the intensity of and time of peak toxic signs [i.e., salivation and choreoathetosis (jerky, involuntary movements)] as well as deltamethrin concentrations in the brain. Rats (n = 5 per age and treatment) were gavaged with either corn oil or 30 mg/kg deltamethrin for the adults and 4 mg/kg deltamethrin for weanlings. The toxic signs observed in the weanlings were as severe as the adults but were longer lasting. Peak brain concentrations of deltamethrin were comparable in both the adult and weanling rats. These findings indicate that weanling animals given a dosage which is 13% of the adult deltamethrin dosage show toxic signs and brain concentrations of deltamethrin comparable to the adult.
This abstract of a proposed presentation does not imply EPA policy.