Effects of IM pretreatment and continuously infused iloprost on I/R-induced changes in hepatic tissue blood flow in rats receiving AT. Animals were subjected to 60 minutes of hepatic ischemia followed by reperfusion as described in Materials and Methods. Animals were injected IV with AT (250 U/kg) 30 minutes before reperfusion or subcutaneously with IM (20 mg/kg) 30 minutes before ischemia. Iloprost was infused continuously starting before the onset of ischemia at a rate of 100 ng/kg/min with or without subcutaneous injection of IM (20 mg/kg) 30 minutes before ischemia. Hepatic tissue blood flow was continuously measured by laser Doppler flowmeter starting 30 minutes before ischemia until 3 hours after reperfusion. Each value represents the mean ± SD derived from 5 animals. (○) I/R animals; (▪) IM-treated I/R animals; (•) AT-treated I/R animals; (▴) AT-treated I/R animals pretreated with IM; (▵) iloprost-treated I/R animals; (□) iloprost-treated I/R animals pretreated with IM. †P< .01 versus I/R. ‡P < .01 versus AT-treated I/R. ¶P < .01 versus IM-treated I/R.