Figure 2.

Short-term incubation with insulin increases the nitric oxide synthesis in fetal endothelium. Nitric oxide (NO) in HUVEC incubated in absence (Control 0, 30 min) or presence of 1 nM insulin (1–30 min). (A) Green fluorescence was observed through confocal microscopy in cells preloaded (30 min) with 4-amino-5-methylamino-2′,7′-difluorofluorescein (DAF-FM). (B) The integrative fluorescence per image was determined using Image J software and normalized by number of cells. (C) Magnification of fluorescence in control and insulin-treated cells, shown in (A). The images (A,C) are representative of triplicates from three different cell cultures.^*P < 0.05 vs. values in the absence of insulin (n = 3).