The study is performed on one group of subjects with body mass index >35 and the absence of type 2 diabetes.~Inclusion criteria:~Body mass index >35 kg/m2.~Exclusion criteria:~Age >80 years. Type 2 diabetes defined as >7 mmol/L in fasting plasma glucose or >11 mmol/L following 2h of oral glycemic load.~Myocardial infarction/unstable angina within 6 weeks prior to the study. Treatment with oral anticoagulants (Warfarin or New oral anticoagulants), Raynaud's phenomenon, peripheral vasculopathies, arterial shunting or other vascular surgery of the study arm.~Any concomitant disease or condition that may interfere with the possibility for the patient to comply with or complete the study protocol.~Participant in an ongoing study. Unwillingness to participate following oral and written information.~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.~Fifteen subjects are included. 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 humans with obesity.