[Inhibitory effect of cholecystokinin octapeptide on lipopolysaccharide-elicited inducible nitric oxide synthase expression in vascular endothelial cells].

OBJECTIVE

To investigate the effect of cholecystokinin octapeptide (CCK-8) on lipopolysaccharide (LPS)-elicited inducible nitric oxide synthase (iNOS) expression in vascular endothelial cells.

METHODS

Human umbilical vein endothelial cell line (ECV-304 cells) was stimulated with vehicle (normal saline) or LPS in the presence (0.01, 0.1, 1 mg/L) or absence (0.1 mg/L) of CCK-8 (10(-6)-10(-8)mol/L). Nitric oxide (NO) level and cellular nitric oxide synthase (NOS) activity were determined with spectrophotometrically. The iNOS expression was detected with immunocytochemical technique and Western blot.

RESULTS

Compared with normal saline, LPS significantly induced the upregulation of iNOS protein expression in the cultured ECV-304 cells, and NOS activity in ECV-304 cells and NO level in cultured media were increased. CCK-8 obviously inhibited above-mentioned effect of LPS in a dose-dependent manner. Whereas CCK-8 alone did not showed effect on iNOS protein expression, NO level and cellular NOS activity as compared with those values when vehicle was used.

CONCLUSION

CCK-8 inhibited LPS-elicited iNOS expression and NO production in ECV-304 cells.