Fig. 2. eNOS regulates the activation of tip cells during retinal angiogenesis.

(A) Retinas from the wild type and eNOS-deficient mice at P6 were stained with IB4 (green). (B) Tip cell number and filopodia length were measured using Image J (National Institutes of Health, MD, USA) software. Images were visualized on confocal microscope at ×80 magnification. Data are presented as the means±SEM. Asterisks indicate statistical significance (p<0.05). Scale bars, 100 µm.