The Effect of Intra-arterial Infusion of Bradykinin on the Nutritive Muscle Blood Flow of the Leg in Obliterative Arterial Disease

Abstract

In patients with segmental occlusions of the femoral artery, intra-arterial infusions of bradykinin provoked a powerful blood flow response in the resting leg as evaluated by venous occlusion plethysmography. An infusion rate of 4–14 μg bradykinin per minute thus mobilized about 80 per cent of the regional blood flow capacity. The infusions did not improve the ability of the leg to perform muscular exercise. The blood flow of the exercising leg muscles as reflected by the elimination rate of radio-iodinated antipyrine from local muscle depots was decreased during the infusion of bradykinin compared with the blood flow during the control period of exercise. The femoral arterio-venous oxygen difference during exercise at the highest working intensity was not influenced by the infusions. The lactate concentrations of arterial and femoral venous blood were slightly higher after exercise performed during bradykinin infusion than in the control study. The results suggest that close intra-arterial infusions of a potent vasodilator like bradykinin into legs with arterial obliterations cause a redistribution of the regional blood flow during exercise in such a way that the blood flow of the active muscles becomes impaired.