FUNDAMENTAL AND APPLIED TOXICOLOGY 10,459-465(1988) Hyperactivity Induced by Triadimefon, a Triazole Fungicide1

agriculturally important triazole fungicide. The present experiments were conducted to charac-terize the effects of triadimefon on a measure of motor activity. Dosage-effect, time-effect, and the effects of repeated dosing (7 days) were determined following triadimefon exposure. Male Long Evans hooded rats, approximately 70 days old, received triadimefon po in 2.0 ml/kg corn oil. Motor activity testing was conducted for 1 hr in figure-eight mazes. For the dosage-effect determination, tnadimefon (50-400 mg/kg) was administered 1 hr prior to testing. In the time-course study, triadimefon (200 mg/kg) was administered either 0.5, 1, 2, 4, 8, or 24 hr prior to testing. In the repeated dosing experiment animals received triadimefon (100 mg/kg) daily for 7 days and were tested 24 hr after the last exposure. Triadimefon produced significant hyperactiv-ity following dosages of 100 and 200 mg/kg. This hyperactivity was rapid in both onset (0.5 hr) and recovery (8.0 hr). Repeated dosing with 100 mg/kg/day revealed no cumulative effects nor tolerance. These results indicate that triadimefon produces a transient hyperactivity at dosages 17 to 33 % of the reported LD50. © 1988 Society ofToxicology Fungicides account for 20 % of worldwide Information on the effects of triazole fungi-pesticide sales, with the use of systemic fungi- cides on mammalian species is scarce. Mac