Thromboangiitis obliterans (TAO; Buerger’s disease) is a non-atherosclerotic, occlusive, inflammatory disease. And it occurs in the distal, small-and medium-size arteries and veins of the arms and legs. Signs and symptoms include pain, intermittent claudication, ischemic ulcers (in the arms, legs or both), thrombophlebitis, etc. It is currently believed that the disease is caused by occlusion of arteriole spasm and thrombosis, leading to ischemia. Another unmerous ischaemic symptom, lumbar spinal canal stenosis (LSCS), is a condition in which the degenerative central canal narrows due to degenerative disc bulging, hypertrophied ligamentum flavum, and degenerative changes in the facet joint.
Limaprost (also known as OP1206), a PGE1 analogue, is a potent and orally active vasodilator. In addition, Limaprost increases blood flow and inhibits platelet aggregation. Furthermore, it has antianginal effects, and has potential for unmerous ischaemic symptoms of TAO and LSCS treatment. For example, oral administration of Limaprost at a dose of >100 μg/kg can relieve vasopressin-induced ST depression of rat electrocardiogram (ECG), which is an animal model of angina pectoris with slight hypotension. In addition, the injection of Limaprost (1-100 ng/kg) in dogs caused a significant increase of coronary blood flow. It has no effect on heart rate, blood pressure, myocardial oxygen consumption and redox potential. Similarly, oral administration of Limaprost inhibits platelet aggregation, adhesion, and thrombocytopenia caused by ADP and collagen infusion in guinea-pigs.
To sum up, Limaprost, a PGE1 analogue, is a potent and orally active vasodilator with vasodilatory, antiplatelet and cytoprotective properties.