Delta opioid receptor analgesia: recent contributions from pharmacology and molecular approaches

Delta opioid receptors represent a promising target for the development of novel analgesics. A number of tools have been developed recently that have significantly improved our knowledge of delta receptor function in pain control. These include several novel delta agonists with potent analgesic properties, and genetic mouse models with targeted mutations in the delta opioid receptor gene. Also, recent findings have further documented the regulation of delta receptor function at cellular level, which impacts on the pain-reducing activity of the receptor. These regulatory mechanisms occur at transcriptional and post-translational levels, along agonist-induced receptor activation, signaling and trafficking, or in interaction with other receptors and neuromodulatory systems. All these tools for in-vivo research, and proposed mechanisms at molecular level, have tremendously increased our understanding of delta receptor physiology, and contribute to designing innovative strategies for the treatment of chronic pain and other diseases such as mood disorders. Behavioural Pharmacology 22:405-414 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.