Prostaglandin E1 in peripheral vascular disease: a PET study of muscular blood flow

Abstract

Background: Increase of blood flow in the ischaemic leg is believed to represent the main action of prostaglandin E (PGE) in the therapy of peripheral vascular disease (PVD). There is no reliable data in man concerning the amount of increase in muscular blood flow (MBF) of the calf, and the difference between intra - arterial and intravenous application. Patients and methods: We conducted a positron emission tomography (PET) study of MBF with O-water as flow tracer. Fifteen patients with PVD and three healthy volunteers were given 5 µg PGE intra - arterially over 50 min; PET scans were taken at 0, 25 and 50 min. Additionally, eight of the patients were investigated during an intravenous infusion of 40 µg PGE over 120 min; PET scans were taken at 0, 30, 60 and 120 min. Results: Increase of muscular blood flow by intra - arterial PGEaveraged 80%. A steal phenomenon was not observed. The amount of flow enhancement depended on whether or not the femoral artery was patent. During intravenous PGE, muscular blood flow remained unchanged. Conclusions: In man, the pharmacodynamic profile of intra - arterial PGEdiffers clearly from intravenous PGE. The flow - enhancing property is lost during metabolization in the lung. Since no difference exists between the therapeutic efficacy of intra-arterial and intra­venous PGE, the impact on muscular blood flow is not as important as suggested previously.