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 .
C0034784
alpha-adrenoreceptor
C0001638
alpha 1-adrenoreceptor