Objective: The aim of this study was to investigate the hemodynamic effects of epinephrine intravenous injection in healthy and hemorrhagic shock rats.
Methods: Forty Sprague-Dawley male rats weighing 250 to 300 g were randomly assigned to 4 groups: group NE, healthy rats receiving epinephrine 2 μg/kg; group NS, healthy rats receiving normal saline; group SE, hemorrhagic shock rats receiving epinephrine 2 μg/kg; and group SS, hemorrhagic shock rats receiving normal saline. Mean arterial blood pressure (MAP) and heart rate (HR) were recorded at the following time points: 0 seconds (baseline), 5 seconds, 15 seconds, 30 seconds, 1 minute, 2 minutes, 4 minutes, 6 minutes, 8 minutes, and 10 minutes (T0-9) after intravenous injection.
Results: There were no significant differences in MAP and HR at baseline between groups NS and NE or between groups SS and SE. Compared with the figures for baseline, MAP had no significant change at all time points in groups NS and SS. MAP increased at T1-9 in group SE (P < 0.01). MAP increased at T1-3 and decreased at T5-6 in group NE (P < 0.01). There was no significant change in HR in all groups after epinephrine or normal saline injection.
Conclusion: Epinephrine 2 μg/kg intravenous injection elicited biphasic changes in blood pressure, which included an initial increase and a subsequent decrease in healthy rats and induced a remarkable increase in blood pressure in hemorrhagic shock rats.
Keywords: epinephrine; health; hemodynamics; hemorrhagic shock; rats.