Objective To investigate the effects of β2-adrenoceptors antagonist ICI 118551 on blood pressure after low dose epinephrine intranasal infiltration in rats. Methods Thirty-two Sprague-Dawley male rats were equally randomized into 4 groups (n=S): saline+saline group (group S), ICI 118551 + saline group (group I), saline+epinephrine group (group E), and ICI 118551 + epinephrine group (group IE). Group S and group I of rats were intravenously injected with saline 0. 2 ml or ICI 118551 0. 5 mg/kg 20 min before intranasal infiltration with 0. 2 ml saline, respectively. Group E and group IE of rats were intravenously injected with saline 0. 2 ml or ICI 118551 0. 5 mg/kg 20 min before intranasal infiltration with 2 μg epinephrine (0. 2 ml), respectively. Mean arterial pressure (MAP) and heart rate (HR) were recorded before infiltration (basline) and 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 min after intranasal initiation. Results Compared with basline, MAP decreased from 3 min to 10 min in group E while increased at 6 min and 7 min in group IE (P展开▼
