Effects of intratracheal instillation of fenvalerate on the ultrastructures of pulmonary alveolar macrophages in rat.
On 1 d after instillation of fenvalerate (Fen) 0.19, 0.93, 4.66, and 23.3 mg.kg-1, and on 30 min, 4 h, 1 d, 4 d, and 7 d after instillation of Fen 4.66 mg.kg-1 by a single intratracheal instillation, respectively, the ultrastructural changes in rat pulmonary alveolar macrophages (PAM) were observed, and the toxicity indices (TI) were calculated. It was found that the ineffective dose of Fen was 0.19 mg.kg-1, and the threshold dose was less than or equal to 0.93 mg.kg-1 as well as the serious intoxication dose greater than or equal to 4.66 mg.kg-1. The results suggest that Fen is quickly toxic to rat lungs and quickly biodegraded in the lungs.