INHIBITOR FOR BLOOD VESSEL HYPERTROPHY

Abstract: An inhibitor for blood vessel hypertrophy containing a compound represented by formula (I) or a pharmaceutically acceptable salt thereof as an active ingredient and having an excellent drug efficacy.

Description: Technical Field This invention relates to use of a compound of formula (I) or a pharmaceutically acceptable salt thereof for production of a vascular hypertrophy inhibitory composition. Background Art It is known that angioplasty, arterial bypass surgery, organ transplantation, etc. frequently entail a hypertrophy and occlusion of the blood vessel owing to, inter alia , proliferation of vascular smooth muscle cells. Though much study is undergoing for finding a useful drug for the prevention and cure of the condition (e.g. J P Kohyo H3-500660 corresponding to WO 89/12068), no effective drug has been discovered as yet. EP-A-0 113 106 discloses a compound of formula (I) and pharmaceutical compositions containing it as an active ingredient. In this document the compound of formula (I) is reported to have antithrombotic and antihypertensic activity. However, a vascular hypertrophy inhibitory activity of the compound is not disclosed in this document. Eur. J. Pharmacol. 183 (4) 1990, 1292 - 1293 discloses the structure of FK 409, (±)-(E)-4-Ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide, which has a potent vasodilating activity. In this document it is reported that FK 409 has effects of increasing endocardial blood flow and the flow ratio of endo/epi in the ischemic region and potent dilating activity on the coronary artery in vitro. It further inhibited epicardial ST-segment elevation caused by partial occlusion of the coronary artery and subsequent atrial pacing in dogs. However, this document does not disclose any suggestion showing relations between increase of endocardial blood flow and proliferation of vascular smooth muscle cells. Inspired by this demand for drugs effective for the prevention and cure of vascular hypertrophy, the inventors of this invention did much research and discovered that a compound of the above formula (I), which is already known to have vasodilatory and antithrombotic activities, is capable of inhibiting vascular hypertrophy. Further research has culminated in the perfection of this invention. Disclosure of Invention The compound of the above formula (I) or a pharmaceutically acceptable salt thereof as an active ingredient are used to produce a vascular hypertrophy inhibitory composition. The vascular hypertrophy inhibitory composition which is produced by using the compound of formula (I) according to the invention finds application as a prophylactic/therapeutic drug for vascular hypertrophy, that is to say the thickening and occlusion of blood vessels owing, inter alia, to the proliferation of vascular smooth muscle cells which occur frequently following various operations in man and animals. The pharmaceutically acceptable salt of compound (I) which is used as the active ingredient in this invention includes salts with inorganic or organic bases such as alkali metal salts, e.g. sodium salt, potassium salt, etc., alkaline earth metal salts, e.g. calcium salt etc., ammonium salt, and organic amine salts such as ethanolamine salt, triethylamine salt, dicyclohexylamine salt and so on. While the compound (I) which is used as the active ingredient in this invention includes its stereoisomers, the representative species is (±)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide (which is hereinafter referred to as FK409). The vascular hypertrophy inhibitory composition which is produced according to this invention is of value as an inhibitor of the hypertrophy (e.g. which can be a cause for restenosis after percutaneous coronary angioplasty) and obstruction of the blood vessel which occur owing, in the main, to the proliferation of vascular smooth muscle cells following angioplasty (e.g. percutaneous coronary angioplasty), arterial bypass procedure, organ transplantation and other operations or a prophylactic/therapeutic drug for vascular hypertrophy and obstruction (or an inhibitor of vascular smooth muscle cell proliferation). The effectiveness of this invention is now shown by way of experimental data. Test Example: Inhibitory effect on intimal hypertrophy following balloon catether-associated carotid artery endothelial injury in rats Method: The test was performed in accordance with the method of Close et al. (Lab. Invest. 49 , 208, 1983), as follows. Male SD rats weighing 400 - 500 g were used. Each rat was anesthetized with pentobarbital sodium and the cervical region was opened. A balloon catheter (Fogarty, 2F) was inserted from the left external carotid artery to the orgin of the common carotid artery. The balloon was then inflated with physiological saline until a slight resistance was felt. The inflated balloon was pulled back as it was to the external carotid artery so as to injure the arterial intima. This operation was repeated 3 times, after which the catheter was withdrawn and the external carotid artery was ligated. After 14 days, the chest was opened under pentobarpital anesthesia and following perfusion with heparin-containing physiological saline (20 units/ml) from the left ventricle, the left common carotid artery was excised and fixed in neutralized formalin. The fixed carotid artery was orcein-stained and microphotographed and the sectional area of the media and that of the hypertrophic portion of the intima were measured by means of an image analyzer (LUZEX2D). The daily administration of the test drug was commenced 2 days preceding the operation and continued till the 13th postoperative day. The intimal thickening inhibitory activity of the drug was determined using the following equation. Intimal thickening inhibition rate (%) = (1- T C )x 100 (where T is the area of the thickened portion of the rat intima in the drug treatment group and C is the corresponding value in the control (vehicle) group). Results: The results are shown in the following table. Drug Dosage n Area of hypertrophic intima (mm 2 ) % Inhibition Control FK409 1 mg/kg x 2, po 6 0.168 ± 0.026 - 5 0.114 ± 0.027 32% 10 mg/kg x 2, po 5 0.054 ± 0.013 68% Control Aspirin 32 mg/kg x 1, po 6 0.154 ± 0.016 - 6 0.153 ± 0.011 1% Control Isradipine 3.2 mg/kg x 1, sc 7 0.173 ± 0.017 - 6 0.135 ± 0.020 22% Control Isosorbide dinitrate 100 mg/kg x 2, po 8 0.172 ± 0.022 - 6 0.152 ± 0.022 12% The vascular hypertrophy inhibitory composition which is produced according to this invention can be used as a solid, semisolid or liquid pharmaceutical preparation containing the active substance of the invention as provided by blending the substance with an organic or inorganic carrier or vehicle suited for topical, oral or parenteral administration. The active ingredient substance can be blended with any nontoxic, pharmaceutically acceptable carriers that are commonly used in various dosage forms including tablets, pellets, capsules, suppositories, injections, solutions, emulsions, suspensions and so on. Among the carriers that can be used are water, glucose, lactose, gum arabic; gelatin, mannitol, starch paste, magnesium trisilicate, talc, corn starch, keratin, colloidal silica, potato starch, urea and other solid, semisolid or liquid pharmaceutically acceptable vehicles. In addition, adjuvants, stabilizers, thickeners, coloring agents and perfumes may be incorporated. The pharmaceutical preparation may contain a preservative or bacteriostat for maintaining the activity of its active ingredient. In such a preparation, the active ingredient should occur in a sufficient amount to produce the desired therapeutic effect according to the stage or severity of the disease. For application of this vascular hypertrophy inhibitor to man, it is preferably administered intravenously, intramuscularly or orally. The dosage or therapeutically effective amount of the objective compound of the invention varies with each patient's age and condition but the daily dose is usually about 0.1 - 100 mg and the unit dose is 10 mg, 50 mg, 100 mg, 250 mg or 500 mg on the average. Industrial applicability As described above, the vascular hypertrophy inhibitor which is used according to claim 1 is used as a prophylactic/therapeutic drug for vascular hypertrophy for inhibiting the thickening and obstruction of blood vessels which occur frequently following various operations.

Claims: Claims for the following Contracting States : AT, BE, CH, DE, DK, FR, GB, IT, LI, LU, NL, SE Use of a compound of the formula or a pharmaceutically acceptable salt thereof for the production of a vascular hypertrophy inhibitory composition. The use claimed in claim 1, wherein the compound is (±)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide. Claims for the following Contracting States : ES, GR Use of a compound of the formula or a pharmaceutically acceptable salt thereof for the production of a vascular hypertrophy inhibitory composition, characterized by blending the compound with a non-toxic, pharmaceutically acceptable carrier, preferably after reacting it with an inorganic or organic base to produce a pharmaceutically acceptable salt. Use according to claim 1, wherein the compound is (±)-(E-)4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide.

Inventors: KATO YASUKO, SADO MIE, SEKI JIRO, KATO, YASUKO, SADO, MIE, SEKI, JIRO, SEKI, JIRO 2-3-19, NOZAKIDORI CHUO-KU
Applicants: FUJISAWA PHARMACEUTICAL CO, FUJISAWA PHARMACEUTICAL CO., LTD.
Application year: 1992
Main classification: A61K31
IPC codes: A61K31