tokens: Animals ( n = 42 ) were treated intraperitoneally with one of the following six regimens : 1 ) L - MED ( the inactive L - isomer of medetomidine ), 30 micrograms / kg ; 2 ) D-MED , 10 micrograms / kg ; 3 ) D-MED , 30 micrograms / kg ; 4 ) D-MED [ 30 micrograms / kg ] and the central - acting alpha - 2 antagonist , idazoxan [ 10 mg / kg ]; 5 ) D-MED [ 30 micrograms / kg ] and the peripheral - acting alpha - 2 antagonist DG-5128 [ 10 mg / kg ], or ; 6 ) saline .