Effects of prostaglandin E-1 infusion on limb hemodynamics and vasodilatory response in patients with arteriosclerosis obliterans

It is well known that prostaglandin E-1 (PGE(1)) increases peripheral blood now. The aim of this study was to investigate the effects of PGE(1) infusion on the hemodynamics and vasodilatory response of the leg affected by intermittent claudication in patients with arteriosclerosis obliterans (ASO). Fourteen legs of 8 male patients with ASO were infused intravenously with PGE(1) (120 mu g/day) for 7 consecutive days. Before the infusion and 5 days after cessation of the infusion, resting skin and skeletal muscle blood now in the calf and occlusion-induced reactive hyperemic now were measured using plethysmography and a laser Doppler flowmeter. Clinical symptoms in the legs were assessed by treadmill exercise testing. Resting calf blood now was found to have increased significantly (skin, from 2.6 +/- 0.1 ml/min/100 g tissue to 2.9 +/-: 0.1 ml/min/100 g tissue, p < 0.02; skeletal muscle, from 3.1 +/- 0.2 ml/min/dl tissue to 4.0 +/- 0.5 ml/min/dl tissue, p < 0.02). There was also a significant reduction in the peripheral vascular resistance (-17.8 +/- 7.2%, p < 0.05)5 days after the cessation of infusion. The time to the half-maximum post peak of hyperemia was significantly elongated (from 34.6 +/- 5.7 sec to 58.6 +/- 9.2 sec, p < 0.01). Borg's score of the legs on exercise testing was markedly reduced, and symptom-free walking distance was increased by an average of 70.9 +/- 15.6%. In conclusion, PGE(1) infusion has vascular effects on not only resting calf blood now but also hyperemic now responses. These retentive effects may be due to alteration in vascular functions and/or rheological state as at result of PGE(1)-induced regular enhancement of blood now, rather than the direct vasodilatory effect of the agent.