FIGURE 1

Capillary depletion: tissue to serum ratios for mice injected with ¹²⁵I-exendin-4 corrected for simultaneously injected ^99mTc-albumin. Values for the cortex are composed of three components: parenchyma (remaining after washout), capillaries (remaining after washout), and reversible vascular association (removed by washout). Significantly more ¹²⁵I-exendin-4 was found in the brain parenchyma than was bound or loosely adherent to the endothelial cells of the capillaries composing the BBB (n=4 mice/group). ***P<0.001 compared with either cortex or parenchyma.