FIGURE 2.

Calcium-independent stimulation of NO production decreased phosphorylation at argininosuccinate synthase Ser-328 (S328). A and C, BAECs were treated with insulin (Ins) at 100 nm (A) or VEGF at 100 ng/ml (C) for 20 min. Phosphorylation (P) was assayed by Western blotting using phospho-specific antibodies and reprobed with eNOS and AS specific antibodies. Blots are representative of three separate experiments. NT, nontreated. B and D, densitometric values represent the percentage of change from nontreated controls normalized to total eNOS or AS, respectively. Densitometric changes are significant with S.E. represented by error bars (n = 3, p < 0.05). E, culture medium from BAECs treated with insulin or VEGF was assayed for nitrite with the DAN assay with S.E. represented by error bars (*, n = 3, p < 0.05).