Cardiovascular mediation of clonidine-induced ultrasound production in infant rats

Mark S. Blumberg, Lisa A. Kreber, Greta Sokoloff, Kristen J. Kent
2000 Behavioral Neuroscience  
In infant rats, administration of the ol 2 adrenoceptor agonist clohidine simultaneously evokes ultrasound production and bradycardia. In this study the authors examined in 8-day-old rats whether these 2 responses to clonidine are causally related. In Experiment 1 pups were pretreated with saline or prenalterol (0.1 or 1.0 mg/kg), a 131 adrenoceptor agonist that increases cardiac rate, followed by administration of clonidine (1.0 mg/kg). Prenalterol pretreatment suppressed clonidine-induced
more » ... asound production at both doses. Prenalterol also increased skin temperature, however, suggesting that suppression of ultrasound was modulated in part by increased body temperature. Consistent with this suggestion, in Experiment 2 mild hyperthermia significantly inhibited clonidine-induced ultrasound production. Finally, in Experiment 3 the authors found that the pretreatments used in Experiments 1 and 2 prevent or dampen the effects of clonidine on cardiac rate. These results suggest that clonidine's effect on ultrasound production is mediated by its effects on the cardiovascular system.
doi:10.1037/0735-7044.114.3.602 fatcat:ha3hpq775jcl5fcmdhz4gds5ee