1. Field of the Invention
The present invention relates to sulfonates of .beta.-cyclodextrin polymer and their uses.
2. Description of the Prior Art
It is known that a significant cause of presentation of the symptoms of angina pectoris, myocardial infarction and the like diseases is coronary arteriosclerosis, which precedes such diseases. Lumen stenosis and loss of elasticity of blood vessels caused by arteriosclerosis result in insufficiency of nutrients and oxygen in myocardial tissues, leading to the symptoms of the above-mentioned diseases. It is said that vascular lumen stenosis is essentially caused by accumulation of foamy macrophage and cholesterol on the inner walls of blood vessels and additionally by cellular fibrous intimal thickening caused by migration of vascular medial smooth muscle cells to intima; also by propagation of the cells in intima. For medical treatment of angina pectoris and myocardial infarction,antithrombotic drugs, vasodilator drugs and the like are used essentially for the purpose of relieving the symptoms of the diseases, which drugs, however, could not cure the vascular lumen stenosis and loss of elasticity of blood vessels caused by arteriosclerosis. Apart from those, no medicines capable of curing the symptoms of the above-mentioned diseases have heretofore been known. In this situation, medicines capable of inhibiting or curing vascular wall hyperplasia, which causes vascular stenosis, are badly needed. Recently, as a means of surgically curing vascular stenosis, percutaneous transliminal coronary angioplasty (PTCA) has become popular. In PTCA, a balloon catheter is inserted into the vascular tract through the crural artery by remote control and the balloon is expanded in the narrowed area of the vein so that the blood vessel is physically expanded. However, the most troublesome problem is that from 30 to 50% of the patients so treated have vascular stenosis again in 3 to 6 months after the operation. The recurrence of the stenosis is not accompanied by deposition of cholesterol on the blood vessel but is a cellular fibrous intimal thickening almost completely of smooth muscle cells and intercellular matrix produced by the cells. Therefore, for inhibition of the recurrence of stenosis after PTCA and also for non-surgical treatment of arteriosclerosis, it is effective to inhibit migration and propagation of the smooth muscle cells produced in the vascular lumen. In the prior art, .beta.-cyclodextrin sulfate (U.S. Pat. No. 5,019,562), heparin fragments (U.S. Pat. No. 5,032,679) and catechol derivatives (Japanese Patent Application Laid-Open No. 4-154720 ) have been reported as useful for such treatment, but an active substance capable of more strongly inhibiting propagation of smooth muscle cells is still very much to be desired.