17 Cannabidiol as an anti-arrhythmic, the role of the CB1 receptors

Cannabidiol (CBD) has been shown to be anti-arrhythmic (Walsh et al , 2010) and tissue sparing (Durst et al , 2007) in an in vivo rat model of coronary artery occlusion (CAO), although the receptors through which this occurs have yet to be identified. This study was designed to investigate whether the antiarrhythmic effects of CBD are modified by co-administration with a CB1 receptor antagonist (AM251). Experimental CAO was induced by ligation of the LAD coronary artery for 30 min; in sodium pentobarbitone anaesthetised male SD rats. Experimental groups included; (i) vehicle, (ii) CBD (50 μg/kg) alone, (iii) AM251 (1 mg/kg) alone, (iv) CBD followed by AM251, and (v) AM251 followed by CBD. CBD or AM251 alone each reduced the incidence of VT and the total number of VEBs compared with the control group, as did AM251 when administered 5 min after CBD. However, in animals treated with AM251 followed by CBD, the antiarrhythmic effect was significantly more pronounced 1274±303 (VT, P