other anaesthetics agents tested were inactive in mm concentrations.5 ketamine ( ic ( 50 ) = 200 mum ) and xylazine ( ic ( 50 ) = 9.5 mum ) were also capable of displacing specific [ ( 3 ) h ] -d-ala ( 2 ) -enkephalin ( d-leu ) binding , as were morphine ( ic ( 50 ) = 95 nm ) and met-enkephalin ( ic ( 50 ) = 40 nm ) .6 on the stimulated guinea-pig ileum , met-enkephalin and morphine inhibited the contractions , the ic ( 50 ) values were 30 nm and 50 nm respectively .
C0014298
enkephalin
C0014295
met-enkephalin