Naidu K A, Radhakrishnamurty R
Nutrition and Food Safety Department, Central Food Technological Research Institute, Mysore, India.
J Toxicol Environ Health. 1989;26(2):203-7. doi: 10.1080/15287398909531245.
Intraperitoneal injection of metalaxyl (250 mg/kg) produced a decrease in heart rate lasting for more than 60 min in anesthetized rats. Pretreatment of rats with phentolamine (a nonselective alpha-adrenoreceptor antagonist, ip at 20 mg/kg) and prazosin (an alpha 1-adrenoreceptor antagonist, ip at 5 mg/kg) significantly reduced the bradycardia induced by metalaxyl. Yohimbine (an alpha 2-adrenoreceptor antagonist, ip at 10 mg/kg) did not change the effect of metalaxyl on heart rate. The results suggest that alpha 2-adrenoreceptors mediate the bradycardic effect of metalaxyl.
腹腔注射甲霜灵（250毫克/千克）可使麻醉大鼠的心率降低，并持续超过60分钟。用酚妥拉明（一种非选择性α-肾上腺素能受体拮抗剂，腹腔注射剂量为20毫克/千克）和哌唑嗪（一种α1-肾上腺素能受体拮抗剂，腹腔注射剂量为5毫克/千克）对大鼠进行预处理，可显著减轻甲霜灵诱导的心动过缓。育亨宾（一种α2-肾上腺素能受体拮抗剂，腹腔注射剂量为10毫克/千克）并未改变甲霜灵对心率的影响。结果表明，α2-肾上腺素能受体介导了甲霜灵的心动过缓效应。
