DAO activity was lower in the dexmedetomidine group than in the control group at 6 and 24 h after liver reperfusion [ 9.77 ( 1.07 ) vs14 .29 ( 1.43 ) units ml ( -1 ) , P = 0.021 ; 9.67 ( 0.98 ) vs 13.97 ( 1.31 ) units ml ( -1 ) , P = 0.017 ] .