Hsu W H, McNeel S V
Drug Chem Toxicol. 1985;8(4):239-53. doi: 10.3109/01480548509038648.
The effect of IV amitraz on the transit of barium sulfate through the stomach and duodenum as well as amitraz-induced bradycardia was studied in 4 dogs. Control transit time and heart rates were determined after IV injection of dimethyl sulfoxide (0.1 ml/kg), which was subsequently used as the vehicle for amitraz administration. The time for barium sulfate to move from the stomach to the duodenojejunal junction was 6.1 +/- 1.3 minutes (mean +/- SEM). An IV injection of amitraz (1 mg/kg) prolonged the transit time to 251.2 +/- 27.0 minutes, and induced marked bradycardia for at least 60 minutes. During the amitraz-induced prolongation of gastrointestinal transit, there were no vigorous gastric contractions for at least 180 minutes. Yohimbine, an alpha 2-adrenergic blocking agent, given IV 20 minutes after amitraz administration, at a dosage of 0.1 mg/kg, reversed both the gastrointestinal and bradycardic effects of amitraz. It was concluded that 1) amitraz causes decreased gastrointestinal motility and bradycardia, and 2) yohimbine may be useful in the control of the untoward reactions caused by amitraz administration.
在4只狗身上研究了静脉注射双甲脒对硫酸钡在胃和十二指肠中通过情况的影响以及双甲脒诱导的心动过缓。在静脉注射二甲基亚砜（0.1毫升/千克）后测定对照通过时间和心率，随后将其用作双甲脒给药的载体。硫酸钡从胃移动到十二指肠空肠交界处的时间为6.1±1.3分钟（平均值±标准误）。静脉注射双甲脒（1毫克/千克）使通过时间延长至251.2±27.0分钟，并诱导明显的心动过缓至少持续60分钟。在双甲脒诱导的胃肠道通过时间延长期间，至少180分钟内没有强烈的胃收缩。在双甲脒给药20分钟后静脉注射育亨宾，剂量为0.1毫克/千克，可逆转双甲脒对胃肠道和心动过缓的影响。得出的结论是：1）双甲脒导致胃肠道蠕动减慢和心动过缓，2）育亨宾可能有助于控制双甲脒给药引起的不良反应。
