ABSTRACT
AIM: To evaluate nitric oxide (NO) production and [3H]arachidonic acid (AA) incorporation into platelet membranes of coronary artery disease (CAD) patients with/without HDL-hypocholesterolemia. MATERIAL: 16 healthy controls (C), 14 CAD patients with plasma HDL-hypocholesterolemia (nCAD) and 14--without HDL-hypocholesterolemia (nCAD). All subjects were without peripheral vascular disease and hypertension. The groups were matched for age, sex, BMI. The diagnosis of CAD was substantiated by coronary angiography. METHODS: Nitric oxide end products xNO (NO2- plus NO3-) levels in the platelet membranes were measured using anion-exchange chromatography. [3H]AA release from labelled platelets was studied by the method of Neufeld and Majerus; radioactivity was measured by liquid scintillation counting. Levels of plasma HDL-cholesterol (HDL-Ch) and triglycerides were enzymatically determined. RESULTS: Significant increase (mean +/- SD; Mann-Whitney U test) of [3H]AA incorporation into platelet membrane phospholipids was noted in CAD patients in comparison with healthy subjects (p < 0.001). A correlation (multiple regression analysis) was established between HDL-C level and [3H]AA (r = -0.58, p < 0.05, n = 28); and between HDL-Ch and NOx levels (r = 0.76, p < 0.05, n = 28) in CAD patients. CAD patients had lower NOx than healthy subjects (p < 0.0001), NOx was lower in the group with decreased HDL-Ch concentration (wCAD 36 +/- 5 vs. nCAD 42.3 +/- 6 mumol/mg, p < 0.002). CONCLUSIONS: CAD patients show decreased ability to produce platelet-derived NO that leads to higher platelet sensitivity to aggregating stimuli. Decreased plasma HDL-Ch may affect AA metabolism and NO production in the platelet membranes of CAD patients without LDL-hypercholesterolemia.
