Plasma concentrations of bovine and porcine heparins. A: Standard curves obtained with the 5th International standard of unfractionated heparin used to determine the plasma concentrations of heparin as IU mL-1. The results are expressed as mean±SE from 60 different standard curves used during the study. B and C: plasma concentration of bovine (in blue) and porcine (in red) heparins as IU mL-1 (B) and as % of Cmax (C). See description of the assay in the Method section. The results in B and C are expressed as mean±SE from 49 and 41 dialysis sessions with bovine and porcine heparin, respectively. The data fitted a linear correlation using a Microcal Origin PC program and the values of linear correlation coefficients (R) are indicated in the panel. In Panel B, * indicates p<0.02 for bovine vs. porcine heparin.