Queirozneto, A.Juang, S. J.Souza, K. R.Akamatsu, A.2014-05-202014-05-201994-06-01Brazilian Journal of Medical and Biological Research. São Paulo: Associação Bras Divulg Cientifica, v. 27, n. 6, p. 1407-1411, 1994.0100-879Xhttp://hdl.handle.net/11449/32945Amitraz, a formamidine insecticide and acaricide used in veterinary practice, presents side effects related to its pharmacological activity on az-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 tip) 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 alpha(2)-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.1407-1411engAmitrazANTINOCICEPTIVE EFFECTALPHA(2)-ADRENERGIC AGONISTSIDAZOXANXYLAZINEDETOMIDINETAIL FLICK TESTWRITHING TESTArtigoWOS:A1994NT47600016Acesso restrito