INCREASED IN-VIVO PLATELET ACTIVATION AND REDUCED INTRAVASCULAR ENDOTHELIUM-DERIVED RELAXING FACTOR AND NITRATE NITRITE PRODUCTION IN PATIENTS WITH INSULIN-DEPENDENT DIABETES-MELLITUS/

Limited information seems to be available about the role of reduced en dothelial production of endothelium-derived relaxing factor (EDRF)-nit rate/nitrite (NO) in the pathogenesis of diabetic angiopathy in insuli n-dependent diabetes. A report of urinary and serum nitrate/nitrite, g lucometabolic parameters, endothelial and in vivo platelet activation markers of 22 insulin dependent diabetics (IDDM) patients are given. U rinary and serum nitrate/nitrite concentrations were reduced in IDDM, This was independent of disease duration, presence of angiopathy and t he glucometabolic parameters. A significant and inverse correlation of nitrate/nitrite excretion with endothelial markers (von Willebrand fa ctor, soluble thrombomodulin) was documented. Moreover, reduced nitrat e/nitrite excretion was strongly associated with elevated plasmatic be ta-thromboglobulin levels. EDRF-NO production is reduced in IDDM and t his reduction correlates with endothelial damage. Decreased nitrate/ni trite excretion may also influence in vivo platelet function, which re sults in increased in vivo platelet activation and suggests that the r educed intravascular production of EDRF-NO might play a role in the pa thogenesis of angiopathy in IDDM.