Suppression of morphine-6-glucuronide-induced vomiting and retching in ferrets with Zangrado, and the effects of CB
receptor antagonism with AM 251. Ferrets treated with the opioid narcotic, morphine-6-glucuronide (M6G) display a substantial emetic response with on average over 12 episodes per hour. Zangrado administration (3 mg/kg ip) 15 minutes prior to M6G resulted in a 77% reduction in emetic episodes (n = 6, P < 0.01). Co-administration of Zangrado with the CB receptor antagonist, AM 251 (5 mg/kg, ip) failed to reverse the anti-emetic effects of Zangrado (n = 6). The slight increase in emetic episodes with AM 251 is comparable to that seen with ferrets treated with AM 251 alone and is thought to reflect the anti-emetic effects of endogenous cannabinoids [20,21].