mu Opioid R/OPRM1 Proteins and Enzymes

The powerful effects of opiate are mediated through the opioid receptors located on the plasma membrane of neurons and other peripheral cells. There are at least 3 types of opioid receptors, mu, kappa, and delta, each with a distinct pharmacologic profile. The mu opioid receptor is the primary site of action for the most commonly used opioids, including morphine, heroin, fentanyl, and methadone.