Naloxone alters pain perception and somatosensory evoked potentials in normal subjects

摘要: THE discovery of opiate-like peptides (endorphins) in brain, blood and cerebrospinal fluid1–4 raises questions as to the physiological role these substances. Given prominent analgesic effects opiates, regulation pain perception is a candidate for endorphin action. Endorphins microinjected into periacqueductal grey matter rats induce analgesia which reversed by naloxone, pure narcotic antagonist5. If endorphins play an active part pain, then naloxone administered man should alter appreciation. Naloxone has not been shown have analgesic, respiratory, euphoric, pupillary or electroencephalogram (EEG) man6. Studies rats7,8 one early study man9 suggested slight hyperalgesic with naloxone. El-Sobky et al.10 failed demonstrate on electric shock judgments five subjects. In experiments reported here, subjects were divided sensitive insensitive subgroups. The found shocks significantly more painful after administration while group experienced them less painful. Evoked potentials showed similar significant differences. These results suggest that individual differences sensitivity may relate system.