Detailed Description:~The study is performed on one group of patients with type 1 diabetes and one group of patients with type 2 diabetes.~Forearm blood flow is determined by venous occlusion plethysmography. Endothelium-dependent vasodilatation is determined during intra-brachial artery infusion of serotonin (21, 70 and 210 ng/min). Endothelium-independent vasodilatation is determined by infusion of sodium nitroprusside (SNP; 1, 3 and 10 µg/min). Each dose is given for 2 min at a rate of 2.5 ml/min. Data are expressed as percentage change in forearm blood from baseline flow.~Twelve subjects are included in each group. On the day of the study the subject arrives to the laboratory after having a light breakfast. Forearm vessels of the non-dominant arm are cannulated and forearm blood flow is determined as described above. Baseline endothelium-dependent and endothelium-independent vasodilatation is determined by intra-arterial infusions of serotonin and SNP, respectively. Thereafter an intra-arterial infusion of the arginase inhibitor N-omega-hydroxy-nor-l-arginine (nor-NOHA) is administered as an intra-arterial infusion at a rate of 0.1 mg/min and is maintained for 120 min. The dose is based on a previous study by our group demonstrating improved endothelial function. Endothelium-dependent and -independent vasodilatation is reassessed at 120 min of infusion.
To evaluate the efficacy of arginase inhibition on endothelial function in patients with type 1 diabetes and type 2 diabetes.