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. Sham-operated animals were prepared in a similar manner, except that blood flow to the left and median hepatic lobes was not obstructed. Mean values of hepatic 6-keto-PGF_1 levels after various periods of hepatic reperfusion are shown. Data represent the mean ± SD derived from six animal experiments. (□) Sham-operated animals; (▪) I/R animals. §P < .01 versus preischemia. *P < .01 versus sham.