Reactome: A Curated Pathway Database

Opioid Signalling (R-HSA-111885)

Species Homo sapiens


Opioids are chemical substances similar to opiates, the active substances found in opium (morphine, codeine etc.). Opioid action is mediated by the receptors for endogenous opioids; peptides such as the enkephalins, the endorphins or the dynorphins. Opioids possess powerful analgesic and sedative effects, and are widely used as pain-killers. Their main side-effect is the rapid establishment of a strong addiction. Opioids receptors are G-protein coupled receptors (GPCR). There are four classes of receptors: mu (MOR), kappa (KOR) and delta (DOR), and the nociceptin receptor (NOP).

Locations in the PathwayBrowser
Literature References
pubMedId Title Journal Year
16612131 Signal transduction induced by opioids in immune cells: a review Neuroimmunomodulation 2006
9218123 G proteins and opioid receptor-mediated signalling Cell Signal 1997
9422713 The many faces of G protein signaling J Biol Chem 1998