Subject(s)

Central Nervous System/metabolism , Chemoreceptor Cells/metabolism , Opium/metabolism , Animals , Anura/metabolism , Arachnida/metabolism , Astacoidea/metabolism , Binding Sites , Binding, Competitive , Brachyura/metabolism , Chickens/metabolism , Cockroaches/metabolism , Culicidae/metabolism , Cyprinidae/metabolism , Decapodiformes/metabolism , Fishes/metabolism , Humans , Methadone/metabolism , Mice/metabolism , Morphinans/metabolism , Rats/metabolism , Schistosoma/metabolism , Schistosoma mansoni/metabolism , Sharks/metabolism , Snails/metabolism , Turtles/metabolism