“D-Amphetamine (2.5-4mg/kg, ip), L-dopa (25mg/kg, sc), L-dopa (25mg/kg, sc) …/kg, sc), alpha-methyl-p-tyrosine (50mg/kg, ip) plus L-dopa (25mg/kg, sc) and pargyline (50mg/kg, ip) … effect of quinine (50mg/kg, ip), while DOPS (… not affect quinine antinociception.”