Effect of metalaxyl on heart rate in rats: role of alpha 1-adrenoreceptors.
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.
Naidu
K A
KA
Nutrition and Food Safety Department, Central Food Technological Research Institute, Mysore, India.
Radhakrishnamurty
R
R
D000409:Alanine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D003864:Depression, Chemical; D006339:Heart Rate / Q000187:drug effects*; D007274:Injections, Intraperitoneal; D008297:Male; D010646:Phentolamine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D011897:Random Allocation; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects* / Q000502:physiology; D015016:Yohimbine / Q000494:pharmacology
D011942:Receptors, Adrenergic, alpha; C028175:metalaxyl; D015016:Yohimbine; D000409:Alanine; D011224:Prazosin; D010646:Phentolamine