Fig. 7.

Changes in eNOS activity and levels of NOx and S-NO. Pre-incubating HAECs with l-arginine for 30 min significantly increased the eNOS activity (means + S.E.M., N = 3, P < 0.01, a) and NOx production (P < 0.01, b), but not S-NO levels (P = NS, c). Inhibition of eNOS by l-NAME pretreatment resulted in reduced eNOS activity (P < 0.01, a) and NOx production (P < 0.01, b) comparing to control cells, but not the S-NO level (P = NS, c). CSE treatment for 4 h changed very little in eNOS activity (P = NS, a) and NOx levels (P = NS, b), and no change in S-NO (c). CSE treatment also did not induce further changes in eNOS activity (a) and NOx levels (b) in cells pretreated with l-arginine, which were still significantly higher than those in controls (P < 0.01 for both). In cells pretreated with l-NAME, which reduced eNOS activity and NOx levels, further CSE treatment made no change to eNOS activity (a) but increased the culture medium NOx levels (b), which became comparable to the control cells. Data are presented as means + S.E.M. at each treatment condition from three individual experiments. Among group difference was analyzed using ANOVA test (P < 0.01 for all). *Bonferroni correction was applied to all P values for between group comparisons.