Nitrite, endothelin and E-selectin plasma levels after arginine infusion in normal and vasculopathic subjects.

Background: The authors carried out a study on the simultaneous modifications of nitrite, endothelin and E-selectin plasma levels after infusion of arginine (a precursor of nitric oxide endothelial synthesis) in normal and vasculopathic subjects.
Methods: The series consisted of 24 female subjects (mean age 58 +/- 7) of which: 12 normal controls; 12 suffering from chronic cerebral vascular disease and coronary heart diseases. Each subject, after a venous blood withdrawal, received arginine (20 g over 2 hours); withdrawals were repeated after 60 and 120 minutes. The levels of total nitrites (NO2-, colorimetric method), endothelin (ET-1, ELISA method) and E-selectin (E-s, ELISA method) were determined on each plasma sample.
Results: The levels of NO2-, specific end-products of nitric oxide, did not show significant changes after arginine infusion in the vasculopathic subjects (group B), whereas in the normal subjects (group A) a significant reduction was recorded. The ET-1 levels after arginine did not show significant differences between the two groups. The values of E-selectin presented no significant variations after arginine in the two groups. The basal values of nitrites, endothelin and E-selectin was significantly (p < 0.05) lower in group B than in group A.
Conclusions: In conclusion, this study has demonstrated that arginine infusion did not alter the nitrite, endothelin and E-selectin plasma levels within two hours in vasculopathic subjects, suggesting a probable wide abiotrophic damage of the endothelial structures. The reduction of nitrites after arginine in the normal subjects may depend of an inverse organification process due to an enhanced bio-synthesis of nitric oxide.