sociated with cancer including management of side effects caused by opioids. Opioids couple opioid receptors and affect several pharmacological effects. In addition to analgesic effects, opioids have side effects such as constipation, nausea and vomiting, and respiratory depression. Mu receptor agonists have been used to control pain and treat side effects caused by opioids, and are even clinically used in an opioid withdrawal syndrome. Our experimental results prove that Exoticin, as a new chemotype for opioid analgesia which does not have opioid-related side effects.
In summary, the 6TM MOR-1 splice variant mMOR-1G is both necessary and sufficient for Exoticin analgesia. With its broad analgesic activity in thermal, inflammatory, and mechanical pain models[33], as well as its lack of side effect such as respiratory depression, physical dependence, and so on, Exoticin may represent a new class of analgesic different from traditional opioids and 6TM variants may be an valuable targets or direction for future analgesic drug development.