Abstract
Fenitrothion residues and cholinesterase (ChE) activities were measured in zebra finches given acute, oral doses of fenitrothion insecticide. Dosage rates were 1.04, 3.80, and 11.36 mg/kg. Residues declined rapidly but were still detectable at trace levels (<0.005 mg/kg) 96 h after treatment. Peak brain and plasma ChE inhibitions averaged between 50–76% and 79–89%, respectively. Plasma ChE recovered more rapidly (1–4 days) than brain ChE (10 days or more). Brain and plasma ChE inhibitions were positively, but weakly, correlated with fenitrothion body burden.