Sera from patients with sepsis induce nitric oxide production in vascular smooth muscle cells

Background: Nitric oxide (NO) is an important physiological mediator of vas cular tone and is involved in pathophysiology of septic shock. Although pla sma nitrite is a stable end product of NO oxidation derived from endogenous NO, the plasma nitrite level is also easily affected by the intake of vari ous foods, bacterial products and renal functional status. Aims: We propose an excellent alternative assay technique for measuring end ogenous NO production. Methods: We measured the nitrite level in cultured vascular smooth muscle c ells (SMC) treated with serum obtained from patients with sepsis (4 patient s), by means of a chemiluminescence detector. Results: The nitrite concentrations in such cells were significantly higher as compared to those in the cells treated with normal serum. Moreover, the increased nitrite levels in the SMC treated with the sera obtained from pa tients with sepsis were completely inhibited by L-nitroarginine (1 mmol /L) , a nitric oxide synthase inhibitor. Conclusion: These data suggest that this assay method enable us to know the ability of endogenous NO production in each patient.