Antinociceptive effect of amitraz in mice and rats

• Autor(a) principal: Queiroz-Neto, A. [UNESP]
• Data de Publicação: 1994
• Outros Autores: Juang, S. J. [UNESP], Souza, K. R. [UNESP], Akamatsu, A. [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/223977
• topic: α2-adrenergic agonists; amitraz; antinociceptive effect; detomidine; idazoxan; tail flick test; writhing test; xylazine

Amitraz, a formamidine insecticide and acaricide used in veterinary practice, presents side effects related to its pharmacological activity on α2-adrenergic receptors. The present study was undertaken to investigate the antinociceptive effect of amitraz in rats and mice. The tail-flick test was used to determine the duration of the antinociceptive effect of the intraperitoneal (ip) administration of amitraz (1 and 2 mg/kg, 10 animals per group) in male Wistar rats weighing 180-220 g. The writhing test (using 10 ml/kg of a 0.6% acetic acid solution as a painful stimulus) was performed in 140 male Swiss mice weighing 20-30 g, divided into 14 groups that received ip injections of saline, amitraz (0.5, 1.0, 1.5, 2.0 and 4.0 mg/kg), xylazine or detomidine (1.0, 1.5, 2.0 and 4.0 mg/kg), in order to compare the effect of amitraz to that caused by xylazine and detomidine, and to investigate the participation of α2-adrenergic receptors which were blocked by idazoxan (1 mg/kg). Amitraz induced a significant antinociceptive effect in both rats and mice. This effect is blocked in mice by idazoxan.