The serum levels of ET in T group on PBD 3 , 7 , 14 [ ( 0.398 + / - 0.035 ) , ( 0.373 + / - 0.005 ) , ( 0.238 + / - 0.019 ) EU/mL ] were significantly lower than those in C group [ ( 0.493 + / - 0.043 ) , ( 0.501 + / - 0.045 ) , ( 0.423 + / - 0.099 ) EU/mL , with t value respectively 6.213 , 9.153 , 15.134 , P < 0.05 or P < 0.01 ] .
