Abstract
Radiocarbon from resmethrin labeled in either the acid or alcohol moiety and administered orally to lactating Jersey cows at 10 mg/kg is rapidly absorbed, metabolized, and excreted. The cis isomer was primarily eliminated in feces, but the trans isomer primarily in urine. Tissue residues at 48 hours post-treatment were low (< 1 ppm) except in liver and kidney, and were generally higher with the alcohol-labeled compounds. Only low levels (0.5 ppm) of radiocarbon were detected in milk. Unmetabolized resmethrin appears in trace amounts in tissue and as the major residue in feces. The major metabolites from both isomers arise from ester hydrolysis and oxidation of the hydrolytic products and include: chrysanthemic acid (free and conjugated with glucuronic acid), chrysanthemumdi carboxylic acid, 5-benzyl-3-furyl methyl carboxylic acid (free and conjugated with both glucuronic acid and glycine) and 5-((alpha)-hydroxy benzyl)-3-furoic acid.
Ridlen, Richard Leo (1983). Distribution and metabolism of CIS and trans-resmethrin (5-benzyl-3-furyl)methyl-2,2-dimenthyl 3-(2-methyl-propenyl)cyclopropanecarboxylate in lactating cattle. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -548510.