Involvement of the Cannabinoid CB1 Receptor in the Opioid Inhibition of the Response to Cholecystokinin and Acute Withdrawal Response

These results show that opioid exposure may also activate the cannabinoid CB1 system, which leads to an inhibition of the opioid acute withdrawal response. This phenomenon and the antagonistic effect of SR on the opioid-induced inhibition of the response to CCK-8 suggest that reciprocal interaction between opioid and cannabinoid systems are operating in the enteric nervous system.