Vascular parameters of pancreatic tumors were evaluated by immunohistochemistry and perfusion studies. A) Representative images of microvessel density (CD31) and pericyte coverage (NG2) in Mia PaCa-2 xenografts at 200x magnification (inset: 400x), with DAPI labeling nuclei. Scale bar, 100 μm. B) Representative images of CD31 and pimonidazole reactivity in MIA PaCa-2 xenografts. Scale bar, 100 μm. C) Representative images of doxorubicin perfusion in AsPC-1 xenografts after acute or chronic exposure to BIBF 1120. Quantification of microvessel density (D), pericyte coverage (E), hypoxia (F), and doxorubicin (perfusion) fluorescence (G) is shown. Bar graphs indicate means + SEM. A minimum of 5 images were acquired per group. Results are mean percentage of thresholded area or absolute vessel counts per field. *, p<0.05; **, p<0.01; ***, p<0.001; ****, p<0.0001 by Dunn’s post-test.