Study protocol After determining the basal FMD ischemia is induced by inflating a cuff to 200 mmHg on the upper arm for 20 min followed by reperfusion. FMD is determined again 20 min after the start of reperfusion . Each individual is examined on three occasions: A) ischemia-reperfusion without intervention, B) ischemia-reperfusion with intervention by RIPC, C) ischemia-reperfusion with RIPC and administration of Ex 9-39. The order of the examination is randomly assigned by drawing one of three numbers. RIPC is performed in cycles of 5 min of inflation (200 mmHg or 20 mmHg above systolic blood pressure) and 5 min deflation of an automatic blood pressure cuff around the left thigh. Two cycles are performed during ischemia and 2 cycles immediately after reperfusion. The GLP-1 receptor antagonist Ex 9-39 is administered as a bolus of 7500 pmol/kg followed by an iv infusion starting 15 min before the initial FMD and maintained until the second FMD at a rate of 500 pmol/kg/min. The dose is based on previous experiences from studies on humans.