Fig 4. A. NO detection by fluorescent dye DAF 2 DA in HUVEC cells after treated with D-Glucose (10, 50mM) for 4 hrs. Scale bar = 50 μ m. B. NO detection by fluorescent dye DAF 2 DA in HUVEC cells after treated with D-Glucose (10, 50mM) for 8 hrs. Scale bar = 50 μ m.