Serum nitrate concentrations in patients with peripheral arterial occlusive disease

Background: Nitric oxide (NO), an endogenous product of L-arginine oxidatio n, seems to account for the vasodilatatory effect of the endothelium-derive d relaxing factor It was the aim of the present study to measure serum nitr ate concentrations, the degradation product of nitric oxide in patients wit h peripheral arterial occlusive disease (PAOD). Patients and methods: 20 patients with PAOD in Fontaine stage IIb, 10 patie nts in stage III and IV respectively were included in the study. Serum samp les for determination of nitrate were taken at admission after fasting over night. Nitrate concentrations were determined using a recently developed hi gh performance liquid chromatography which allows direct measurement of nit rate. The control group comprised 14 age and risk factor matched volunteers . Results: We found significantly increased nitrate concentrations inpatients with PAOD compared to the control group [stage IIb: 6.65 +/- 1.58 mu mol/l ; stage III: 6.94 +/- 1.85 mu mol/l, stage IV: 7.05 +/- 1.16 mu mol/l; cont rol: 4.41 +/- 1.24 mu mol/l] however no significance was calculated within the different PAOD groups. There was no association of either diabetes mell itus, hypertension and smoking behaviour with increased nitrate levels. Conclusion: These data might indicate that NO might be involved in adaptive vasodilatation already in the early phase of the disease. The source of ni trate in PAOD patients, however remains unclear.