Immunohistologic localization of NTPDases in the cardiac microvasculature.

Immunohistochemistry of mouse heart sections (A-G) are shown in the same order as in Figure 4. Antibody specificity: (A) NTPDase1, (B) NTPDase2, (C) α-actin (a marker of smooth muscle), (D) CD31 (a marker of endothelium), (E) NG2 (a marker of pericytes and smooth muscle cells), (F) laminin (a marker of basement membranes), and (G) a higher magnification of NTPDase2. Sections were counterstained with hematoxylin. In panels H-M, immunofluorescence and confocal analysis were performed: (H) NTPDase1 in green and CD31 in blue (colocalization is aquamarine); (I) NTPDase1 in green and NTPDase2 in red; (J) CD31 in blue and NTPDase2 in red (no colocalization); (K) pericyte marker NG2 in green; (L) NTPDase2 in red; (M) panels K and L combined (colocalization is yellow). In the microvasculature, NTPDase1 colocalized with an endothelial cell marker (CD31) while NTPDase2 colocalized with a pericyte marker (NG2). Original magnifications A-F and H-M, ×200; G, ×400.