Nitric oxide plasma levels in patients with chronic and acute cerebrovascular disorders

Abstract

Background: The authors carried out a study on plasma level of nitrites, stable end-products of nitric oxide, aimed at investigating some features of the cerebral microvascular function in chronic and acute cerebrovascular disorders,

Methods: The series consists of 16 patients with chronic cerebral vascular disease, 11 patients with TIA, 28 patients with thrombotic stroke and 27 normal controls; the diagnosis was done on the basis of clinical, ultrasonographic and tomodensitometric findings. For each subject the determination of nitrate plasma levels by a method based on the colorimetric reaction (developed by nitrites dissolved in an acid solution containing sulfanilamide) was performed; this reaction yields quantitative results exactly corresponding to the amount of nitric oxide.

Results: In chronic cerebrovascular patients NO2-values tendentially higher (16.4 +/- 0.52 mumol/l) but not statistically different from those of controls (13.2 +/- 0.52) were obtained; also the values found in the group with TIA, even if slightly reduced (8.0 +/- 1.4 mumol/l), did not differ from controls; in the stroke group a significant (p < 0.05) reduction (6.4 +/- 0.52 mumol/l), as compared to controls, was found.

Conclusions: On the basis of these results and of the literature data on the physiopathological profile of NO, the authors suggest a compensatory increase of the basal tone of NO in chronic cerebrovascular diseases, while an impaired endothelial synthesis of the marker could play a critical role in TIA patients and more evidently in stroke patients, presenting a wide microvascular area completely and irreversibly excluded.