Nitric Oxide, Platelets and Septicemia

Bleeding is a welldmown complication of uraemia that is attributed to the suppression of platelet function by the disease process. Interestingly, L-arginine and some ofoer platelet-inhibitory metabolites of the urea cycle are accumulated in uraemia (Horowitz et al 1970) and this is associated witii an increase in TNF levels (Noris et al 1993). It has been shown that platelets obtained from luaemic patients generate more NO than controls so tiiat increased expression and/or activity of NOS may play a role in platelet dysfunction observed in uraemia (Noris et al 1993). 

2 Nitric oxide, platelets, tumor growth aud metastasis 

Recent studies have shown that platelets ate one of the cytotoxic effector cells against neoplasia (for review Okada et al 1996). It has been shown that the cytotoxic effects of activated platelets against lung cancer cells in culture may depend on the activity of platelet NOS (Okada et al 1996). 

9 Pharmacology of NO generation and action in tiie platelet microenviro-nment 

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