Kappa-opioid receptor agonists
A kappa opioid receptor agonist (KORA) is a substance that binds to a kappa opioid receptor and triggers a response in a cell. The receptors of the human body work by being stimulated or inhibited by natural (such as hormones and neurotransmitters) or synthetic (such as drugs) agonists and antagonists, respectively.1
Research has revealed that local application of exogenous opioid agonists produces a potent analgesic effect by activating peripheral opioid receptors in inflamed tissues. The analgesic activity occurs without activation of opioid receptors in the central nervous system (CNS), and therefore centrally mediated side effects, such as respiratory depression, mental clouding, altered consciousness, or addiction, are not associated with peripheral opioid activity. This discovery has stimulated research on developing peripherally restricted opioid agonists that lack CNS effects. In addition, it has been recognized that opioid receptors modulate inflammation, and that opioids have anti-inflammatory effects. The anti-inflammatory actions of opioids are not well known or understood. Conflicting reports on mu-opioids suggest both anti-inflammatory and pro-inflammatory effects.2
