1. Supplemental Data Figure 4: Reverse phase-HPLC of extracts from coronary sinus and femoral artery plasma from subject 6. Each fraction was assayed with three separate immunoassays: N-terminal assay – solid dark grey line and triangles, commercial assay – heavy black line and closed circles, and C-terminal assay – light grey line and open circles. The elution positions of BNP(1-32) and BNP(3-32) standards are shown by the large and small arrows respectively, and that of proBNP by the square bracket. Major peaks have been numbered to correspond with those in the text. The hatched areas cover large peaks due to interference in our assay from proteolytic enzyme inhibitors used for blood collection.