Some behavioral effects of the pesticide amitraz

ABSTRACT

Acute oral administration of the pesticide amitraz at the doses of 60 and 100 mg/kg (N = 10 per group) significantly decreased the rearing frequency of rats observed in a open field to 8 + or - 8 and 5 + or- 5, respectively, when compared to 28 + or - 5 for control rats treated with vehicle only. The same doses of amitraz (N = 10 per group) increased duration of immobility to 80 + or - 50 and 113 + or - 64 s, respectively, when compared to 113 + or - 64 s for the controls. Acute oral administration of amitraz (20, 60 or 100 mg/kg, N = 10 per group) significantly increased the convulsive threshold dose of rats for strychnine, picrotoxin and pentylenetetrazole. A mitraz administered ip to mice at the doses of 20, 60 and 100 mg/kg (N = 10 per group) significantly increased sleeping time in a dose-dependent manner to 96 + or - 26, 120 + or - 29 and 198 + or - 58 min, respectively, when compared to 45 + or - 15 min for control mice treated with vehicle only. These results indicate that amitraz produces a depressant effect on the central nervous system