Effects of AT, Trp⁴⁹-modified AT, DEGR-Xa, and AT plus IM pretreatment on changes in hepatic 6-keto-PGF_1 levels in rats subjected to hepatic I/R. Animals were subjected to 60 minutes of hepatic ischemia followed by reperfusion as described in Materials and Methods. Animals were either injected IV with AT (250 U/kg), Trp⁴⁹-modified AT (250 U/kg), or DEGR-Xa (3 mg/kg) 30 minutes before reperfusion or injected subcutaneously with IM (20 mg/kg) 30 minutes before ischemia. After 1 hour of reperfusion, hepatic 6-keto-PGF_1 levels were measured by enzyme immunoassay (EIA). Each bar represents the mean ± SD. *P < .01 versus sham. †P < .01 versus I/R. ‡P < .01 versus AT-treated I/R.