Percent increase of leptin but not adiponectin release in hepatic vein after BDL operations in fa/fa and their lean littermates. Leptin and adiponectin measurements were made by radioimmunoassay as described in Materials and Methods. Measurements were taken from both the portal (PV) and hepatic vein (HV) before sacrifice, and the mean differences were calculated to assess the mean circulating leptin and adiponectin concentration. Shown here is the percent fold increase of leptin and adiponectin concentrations in hepatic vein with respect to leptin or adiponectin levels in portal vein taken as 100%. Only lean littermates that underwent BDL showed a significant 1.5-fold increase of leptin levels in HV as compared to PV (*P < 0.01). This difference in leptin concentration from HV and PV was not observed in the fa/fa BDL group of rats. The same was true for adiponectin also and as shown in Figure 4B, no statistically significant difference of adiponectin was observed in HV and PV of lean BDL and fa/fa BDL group of rats (P = 0.06; n = 10 per treatment group, leptin concentrations in ng/ml). All of the rats from either the fa/fa or lean groups underwent sham operation without differences, in HV versus PV, for both leptin and adiponectin (data not shown here).