whereas the initial phase of the endorphin-induced rise in rt was partially attenuated by naloxone ( 5 or 20 mg/kg i.p . ) or naltrexone ( 3 mg/kg i.p . ) , the late phase was completely blocked by the prostaglandin synthetase inhibitor , indomethacin ( 15 mg/kg i.p . ) .
C0027358
naloxone
C0027360
naltrexone