Effect of Cannabinoid Receptor Agonist WIN55, 212-2 on the Anxiety Induced by PTSD in Male Rats

Introduction: Posttraumatic stress disorder is a severe anxiety disorder caused by exposure to traumatic events. The aim of this study was to induce PTSD in rats and examine the effect of WIN55-212-2, a cannabinoid receptor agonist, on anxiety. Methods: SPS&S model was used to induce PTSD in 56 male Wistar rats. Rats were restrained for 2 h, immediately followed by forced swimming for 20 min. After 15 min of recuperation, animals were exposed to diethyl ether until they lost consciousness. Thirty min later, rats received an electric foot shock in a shock chamber. Rats which were in the shock group, without experiencing SPS, only received an electrical foot shock. Animals received IP injections of WIN (two doses) or vehicle, before tests, in 3 continuous days. For PTSD induction, conditioned fear response was measured. Anxiety-like behavior was examined twice with elevated plus-maze. Results: PTSD induction with SPS&S significantly decreased open arm time (OAT) and open arm entry (OAE) parameter, as compared to the control. WIN (0.25 mg/kg) significantly increased OAT as compared with the control. Conclusion: WIN (0.25 mg/kg) decreased the anxiety like behavior induced by PTSD, so it seems to have antianxiety effect.