Preventive effect of paroxetine and nimodipine on posttraumatic stress disorder in rats

Abstract

Objective To evaluate the preventive effect of paroxetine and nimodipine on posttraumatic stress disorder (PTSD) in rats. Methods Fifty rats were divided into normal group, model group, treatment group Ⅰ, treatment group Ⅱ and combined treatment group according to the random number table, with 10 rats each. The rat model of PTSD was induced by complex stress. Two days after the modeling, the normal and model groups were treated with normal saline intraperitoneally (1 ml/kg), treatment group Ⅰ were given oral use of paroxetine (20 mg/kg), treatment group Ⅱ were treated with nimodipine intraperitoneally (1 ml/kg), and combined treatment group were given paroxetine orally (20 mg/kg) and nimodipine intraperitoneally (1 ml/kg). After 14 days of medication, open field test, elevated plus maze and Morris water maze were performed to examine the preventive effect of paroxetine and nimodipine in PTSD rats. Results Between model and normal groups significant differences were detected in grid-crossing frequency (28.6±15.4 vs 85.7±15.8), time in open and closed arms [(34.7±20.3)s vs (80.5±17.0)s; (240.3±28.2)s vs (154.7±26.8)s], frequency of reaching the target quadrant (1.1±0.6 vs 2.8±1.9) and escape latency [(21.5±14.4)s vs (6.4±4.0)s] (P<0.05). In contrast to model group, frequency and duration of time in the open field center and frequency and time in open arms of the elevated plus maze were more in treatment group Ⅰ and combined treatment group (P<0.01); frequency of reaching the target quadrant increased and escape latency shortened in treatment group Ⅱ and combined treatment group (P<0.01). Conclusion Paroxetine and nimodipine are effective to prevent anxiety and dysfunction of learning and memory of PTSD rats. Key words: Stress disorders, post-traumatic; Neurobehavioral manifestations; Paroxetine; Nimodipine