Nitric oxide synthesis and isoprostane production in subjects with type 1 diabetes and normal urinary albumin excretion. Diabetes

The role of nitric oxide (NO) and free radicals in the development of microvascular disease in type 1 dia-betes remains unclear. We have measured NO and iso-prostane (a stable marker of in vivo lipid peroxidation) production in 13 type 1 diabetic subjects with normal urinary albumin excretion and 13 healthy volunteers. Whole-body NO synthesis was quantified by measuring the urinary excretion of 15N-nitrate after the intra-venous administration of L-[15N]2-arginine. The urinary excretion of the major urinary metabolite of 15-F2t-iso-prostane (8-iso-prostaglandin-F2), 2,3-dinor-5,6-dihydro-F2t-IsoP, was quantified as a marker of in vivo lipid per-oxidation. Whole-body NO synthesis was significantly higher in diabetic subjects compared with control sub-jects (342 vs. 216 nmol 15N-nitrate/mmol creatinin