JP5747263B2 - Neuronal death inhibitor - Google Patents

Description

  The present invention relates to a drug for suppressing delayed neuronal cell death caused by transient cerebral ischemia containing cyclic phosphatidic acid or carbacyclic phosphatidic acid as an active ingredient.

  Cerebrovascular disease includes any brain abnormality caused by a vascular pathological process. Vascular pathological processes are considered to include any one or more of the following. There are changes due to occlusion of the lumen of blood vessels due to thrombus or embolism, rupture of blood vessels, changes in permeability of blood vessel walls, increased viscosity of blood quality, and the like.

  Cerebrovascular disease typically manifests as seizures, which can be characterized as brain tissue death caused by lack of blood flow and insufficient oxygen to the brain. In the West, seizures are the main cause of death following heart disease and cancer. In Japan, the mortality rate of cerebrovascular disorders is decreasing, but the incidence is increasing, accounting for about 40% of the bedridden causes of the elderly.

  Seizures are ischemic or hemorrhagic. In an ischemic stroke, the blood supply to a part of the brain is reduced or stopped by a blood clot that occludes a blood vessel or by atherosclerosis. Reduced or stopped blood flow to the brain is known as cerebral ischemia. Cerebral ischemia can last from a few seconds to several minutes, and if the ischemia occurs for more than a few minutes, an infarction of the brain tissue occurs. In addition, cerebral ischemia can also result from circulatory and hypotensive disorders resulting from severe and prolonged heart failure or shock.

  Until now, some therapeutic agents for cerebral ischemic disease have been used in clinical practice and have contributed to the lifesaving of many patients, but they are effective enough for treatment after the onset of seizures. The current situation is that we have not obtained it. Further, in the following literature, as a method for preventing and treating a disease causing neuronal cell death, a technique using lysophosphatidylethanolamine (Patent Document 1), a glutamate receptor agonist (Patent Document 2), pyridoxine, pyridoxamine and the like ( Patent Document 3), preventive agent containing phosphatidylcholine and the like as an active ingredient (Patent Document 4), docosahexaene and derivatives thereof (Patent Document 5), pharmaceutical composition containing dilinoleoylphosphatidylethanolamine as an active ingredient (Patent Document 6), Lysophosphatidic acid, lysophosphatidylinositol, etc. (Patent Document 7) are known.

JP 2007-22966 A JP 7-196533 A JP-T-2003-528146 JP 2000-239168 A JP-A-2-49723 JP 2005-247728 A Japanese National Patent Publication No. 11-512439

  However, there is no therapeutic drug that has been shown to have a sufficient effect on the pathological condition caused by delayed neuronal death due to transient cerebral ischemia due to cerebrovascular disorder, and the development of a new drug is required. ing. That is, an object of the present invention is to provide a novel neuronal cell death inhibitor having an action of suppressing delayed neuronal cell death caused by transient cerebral ischemia.

  The present inventor has already found that cyclic phosphatidic acid and its derivatives have neuronal differentiation induction, neuronal neurite outgrowth action, and suppress brain neuronal cell death. Cyclic phosphatidic acid or carbacyclic phosphatidine The present inventors have found that acids and derivatives thereof suppress delayed neuronal cell death due to transient cerebral ischemia, and have completed the present invention.

That is, according to this invention, the chemical | medical agent for suppressing the delayed neuronal cell death by transient cerebral ischemia containing cyclic phosphatidic acid, carb cyclic phosphatidic acid, or its salt is provided.
Preferably, the cyclic phosphatidic acid or the carbcyclic phosphatidic acid is a compound represented by the formula (1).
(In the formula, R is a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, or a linear or branched group having 2 to 30 carbon atoms. An alkynyl group, which may contain a cycloalkane ring or an aromatic ring, wherein X and Y each independently represent —O— or —CH ₂ —, wherein X and Y are simultaneously —CH _2; (M is a hydrogen atom or a counter cation.)

Preferably, in the general formula (1), X and Y are —O—.
Preferably, in the general formula (1), X or Y is —CH ₂ —.
Preferably, in the general formula (1), R is C ₁₅ H ₂₉ or C ₁₇ H ₃₃ .

  According to the present invention, the transient cerebral ischemia further comprising administering cyclic phosphatidic acid or carbacyclic phosphatidic acid or a salt thereof to a patient with delayed neuronal cell death due to transient cerebral ischemia. A method for inhibiting delayed neuronal cell death caused by is provided.

  The present invention further provides use of cyclic phosphatidic acid, carbacyclic phosphatidic acid or a salt thereof for the manufacture of a medicament for suppressing delayed neuronal cell death due to transient cerebral ischemia. .

  According to the present invention, there is provided a drug for suppressing delayed neuronal cell death caused by transient cerebral ischemia with few side effects, comprising cyclic phosphatidic acid or carbacyclic phosphatidic acid as an active ingredient. Can be provided.

FIG. 1 shows the effects of 2 ccPA (carbacyclic phosphatidic acid) and cPA (cyclic phosphatidic acid) on hippocampal CAI region delayed neuronal death associated with transient cerebral ischemia treatment. FIG. 2 shows the results of observation of the hippocampal CAI region associated with transient cerebral ischemia treatment. FIG. 3 shows the effects of 2 ccPA (carbacyclic phosphatidic acid) and cPA (cyclic phosphatidic acid) on hippocampal CAI region delayed neuronal death associated with transient cerebral ischemia treatment.

Hereinafter, the present invention will be described more specifically.
In the examples described hereinbelow, an experiment in which delayed neuronal cell death is induced by transient cerebral ischemia treatment on pyramidal cells in the rat hippocampal CA1 region including the control group. The system was used. In this experimental system, it was clearly shown that cyclic phosphatidic acid or carbcyclic phosphatidic acid has a function of suppressing delayed neuronal cell death in the same region.

  The delayed neuronal cell death caused by transient cerebral ischemia is a cause of hindering the therapeutic effect of diseases such as cerebral infarction. The mechanism is not yet clear, but it is thought that after transient cerebral ischemia, a neuronal cell death-determining mechanism works, which eventually proceeds irreversibly to a common pathway of apoptosis. . At that time, after transient cerebral ischemia in the hippocampal CA1 region, it is reported that the function of ubiquitin / proteasome is irreversibly decreased prior to delayed neuronal cell death, which causes neuronal cell death. At that time, it has been clarified that caspase 3 and p53 are indispensable (Yonekura, I., Takai, K., Asai, A., Kawahara, N., Kirino, T. p53 potentiates hippocampal neuronal death caused by global ischemia. J. Cereb. Blood Flow Metab., 26: 1332-1340 (2006); and Asai, A., Tanahashi, N., Qui, J.-H., Saito, N., Chi S, Kawahara, N., Tanaka, K., Kirino, T. Selective proteasomal dysfunction in the hippocampal CA1 rregion after transient forebrain ischemia. J. Cereb. Blood Flow Metab.

  In addition, due to ischemia due to the development of acidosis due to anaerobic metabolism, Na + intracellular influx occurs, cells expand due to Na + loading, and subsequent recirculation causes free radical generation and Ca2 + influx, Cell membrane damage caused by free radicals has been reported to cause further Ca2 + increase and eventually cell membrane destruction resulting in cell death (Katsuji Hashimoto, Satoshi Yoshioka, Kenichi Imahashi, Hideo Sasaoka Calsim and reperfusion injury Respiration and circulation 49: 43-49 (2001)). After reperfusion, oxidative stress due to free radical production from arachidonic acid metabolic system and nitric oxide synthase also promotes cell death (Love, S. Oxidative stress in brain ischemia. Brain Pathol. 9: 119-131 (1999)). This suggests that administration of a free radical scavenger at the time of reperfusion may block or reduce the reperfusion injury by blocking the pathway to cell death. Generic name: edaravone). This is a substance that suppresses peroxidation of cell membrane lipids by scavenging free radicals and exhibits a brain-protecting action, and its mechanism of action is completely different from cPA in this study.

  That is, the agent of the present invention can be used for suppressing delayed neuronal cell death due to transient cerebral ischemia, and contains cyclic phosphatidic acid, carbacyclic phosphatidic acid or a salt thereof as an active ingredient. The cyclic phosphatidic acid or the carbcyclic phosphatidic acid is not particularly limited as long as it exhibits the effects of the present invention, but a cyclic phosphatidic acid represented by the following formula (I) can be preferably used.

(In the formula, R is a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, or a linear or branched group having 2 to 30 carbon atoms. An alkynyl group, which may contain a cycloalkane ring or an aromatic ring, wherein X and Y each independently represent —O— or —CH ₂ —, wherein X and Y are simultaneously —CH _2; (M is a hydrogen atom or a counter cation.)

  In the formula (I), specific examples of the linear or branched alkyl group having 1 to 30 carbon atoms represented by the substituent R include, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. , Heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl and the like.

  Specific examples of the linear or branched alkenyl group having 2 to 30 carbon atoms represented by the substituent R include, for example, an allyl group, a butenyl group, an octenyl group, a decenyl group, a dodecadienyl group, a hexadecatrienyl group, and the like. More specifically, 8-decenyl group, 8-undecenyl group, 8-dodecenyl group, 8-tridecenyl group, 8-tetradecenyl group, 8-pentadecenyl group, 8-hexadecenyl group, 8-heptadecenyl group, 8- Octadecenyl group, 8-icosenyl group, 8-docosenyl group, heptadec-8,11-dienyl group, heptadec-8,11,14-trienyl group, nonadeca-4,7,10,13-tetraenyl group, nonadeca-4, 7,10,13,16-pentaenyl group, henicosa-3,6,9,12,15,18-hexaenyl group, etc. It is.

  Specific examples of the linear or branched alkynyl group having 2 to 30 carbon atoms represented by the substituent R include, for example, 8-decynyl group, 8-undecynyl group, 8-dodecynyl group, 8-tridecynyl group, and 8-tetradecynyl group. Group, 8-pentadecynyl group, 8-hexadecynyl group, 8-heptadecynyl group, 8-octadecynyl group, 8-icosinyl group, 8-docosinyl group, heptadec-8,11-diynyl group and the like.

  Specific examples of the cycloalkane ring that can be contained in the alkyl group, alkenyl group, or alkynyl group include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, and a cyclooctane ring. The cycloalkane ring may contain one or more heteroatoms, and examples thereof include an oxirane ring, an oxetane ring, a tetrahydrofuran ring, and an N-methylprolysine ring.

  Specific examples of the aromatic ring that can be contained in the alkyl group, alkenyl group, or alkynyl group include a benzene ring, a naphthalene ring, a pyridine ring, a furan ring, and a thiophene ring.

  Therefore, specific examples when the substituent R is an alkyl group substituted with a cycloalkane ring include, for example, a cyclopropylmethyl group, a cyclohexylethyl group, an 8,9-methanopentadecyl group, and the like.

  Specific examples when the substituent R is an alkyl group substituted by an aromatic ring include a benzyl group, a phenethyl group, a p-pentylphenyloctyl group, and the like.

  R is preferably a linear or branched alkyl group having 9 to 17 carbon atoms, a linear or branched alkenyl group having 9 to 17 carbon atoms, or a linear or branched alkynyl group having 9 to 17 carbon atoms. It is a group. R is more preferably a linear or branched alkyl group having 9, 11, 13, 15 or 17 carbon atoms, or a linear or branched alkenyl group having 9, 11, 13, 15 or 17 carbon atoms. is there. R is particularly preferably a linear or branched alkenyl group having 9, 11, 13, 15 or 17 carbon atoms.

X and Y in the compound represented by the general formula (1) each independently represent —O— or —CH ₂ —, but X and Y are not simultaneously —CH ₂ —. That is, there are the following three combinations of X and Y.
(1) X is —O— and Y is —O—.
(2) X is —CH ₂ — and Y is —O—.
(3) X is —O— and Y is —CH ₂ —.

  M in the cyclic phosphatidic acid derivative represented by the formula (I) is a hydrogen atom or a counter cation. Examples of the case where M is a counter cation include, for example, an alkali metal atom, an alkaline earth metal atom, and a substituted or unsubstituted ammonium group. Examples of the alkali metal atom include lithium, sodium, and potassium, and examples of the alkaline earth metal atom include magnesium and calcium. Examples of the substituted ammonium group include a butyl ammonium group, a triethyl ammonium group, and a tetramethyl ammonium group.

  The compounds of formula (I) may have isomers such as positional isomers, geometric isomers, tautomers, or optical isomers depending on the type of substituent, but all possible Isomers and mixtures containing two or more of these isomers in any ratio are also within the scope of the present invention.

  The compound of formula (I) may exist in the form of an adduct (hydrate or solvate) with water or various solvents, and these adducts are also within the scope of the present invention. is there. Furthermore, any crystalline form of the compound of formula (I) and salts thereof is within the scope of the invention.

  Among the compounds represented by the general formula (1), compounds in which X and Y are —O— are, for example, JP-A-5-230088, JP-A-7-149772, JP-A-7-258278, It can be chemically synthesized according to the method described in Kaihei 9-25235.

Moreover, the compound whose X and Y are -O- among the compounds shown by General formula (1) makes phospholipase D act on lyso-type phospholipid according to the method as described in Unexamined-Japanese-Patent No. 2001-178489. Can also be synthesized. The lyso-type phospholipid used here is not particularly limited as long as it is a lyso-type phospholipid capable of acting on phospholipase D. Many types of lyso-type phospholipids are known, those having different fatty acid types, and molecular types having ether or vinyl ether bonds are known, and these are available as commercial products. As phospholipase D, those derived from higher plants such as cabbage and peanuts, and those derived from microorganisms such as Streptomyces chromofuscus and Actinomadula sp. Are available as commercially available reagents, but are extremely selected by the enzyme derived from Actinomadula sp. CPA is synthesized (Japanese Patent Laid-Open No. 11-367032). The reaction between lyso-type phospholipid and phospholipase D is not particularly limited as long as the enzyme can exhibit its activity. For example, it is heated from room temperature in an acetic acid buffer solution (about pH 5 to 6) containing calcium chloride. (Preferably at about 37 ° C.) for about 1 to 5 hours. The produced cPA derivative can be purified by extraction, column chromatography, thin layer chromatography (TLC) or the like according to a conventional method.

Further, among the compounds represented by the general formula (1), a compound in which X is —CH ₂ — and Y is —O— is described in JP-A No. 2004-010582 or International Publication No. WO 03/104246. It can be synthesized by the method.

In addition, among the compounds represented by the general formula (1), a compound in which X is —O— and Y is —CH ₂ — can be obtained by the method described in the literature (Kobaashi, S., et al., Tetrahedron Letters 34, 4047- 4050 (1993); and "Japan Pharmaceutical Association 23rd Symposium on Progress in Reactions and Synthesis, November 17 and 18, 1997 (Kumamoto Civic Center) Synthesis and Physiological Actions of Cyclic Phosphatidic Acid and Carba Derivatives, Abstracts Page 101- 104 ") and can be synthesized by the method described in International Publication No. WO2002 / 094286. An example of a specific synthesis route is shown below.

In the above, first, the commercially available (R) -benzyl glycidyl ether (1) is activated with BF ₃ .Et ₂ O, and the thio compound obtained by reacting n-BuLi with methylphosphonic acid dimethyl ester is reacted. To obtain alcohol (2).
The obtained alcohol is reacted at 80 ° C. with an excess of pyridinium salt of p-toluenesulfonic acid in toluene to obtain a cyclized product (3). This cyclized product is subjected to hydrogenolysis using 20% Pd (OH) ₂ —C under hydrogen atmosphere to perform debenzylation (4). Using 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride as a condensing agent, it is reacted with a fatty acid to obtain a coupled product (5). Next, using bromotrimethylsilane as a nucleophile, only the methyl group is regioselectively removed to obtain cyclic phosphonic acid (6). This is transferred to a separatory funnel using ether, and a small amount of 0.02N aqueous sodium hydroxide solution is added dropwise to carry out a liquid separation operation to extract and purify the target compound as a sodium salt (7).

  Cyclic phosphatidic acid or carbacyclic phosphatidic acid used as an active ingredient in the present invention can suppress delayed neuronal cell death due to transient cerebral ischemia. The drug of the present invention can be used as a drug for suppressing delayed neuronal cell death due to transient cerebral ischemia.

  The drug of the present invention comprises one or more pharmaceutically acceptable pharmaceutical additives and an active ingredient, cyclic phosphatidic acid or carbacyclic phosphatidic acid (preferably a compound represented by the formula (1)). It is preferably provided in the form of a pharmaceutical composition comprising.

  The drug of the present invention can be administered in various forms. Suitable administration forms include oral administration and parenteral administration (for example, intravenous, intramuscular, subcutaneous or intradermal injection, rectal administration, etc. Administration, transmucosal administration, etc.). Examples of the pharmaceutical composition suitable for oral administration include tablets, granules, capsules, powders, solutions, suspensions, syrups, etc. Examples of the pharmaceutical composition suitable for parenteral administration include , Injections, drops, suppositories, transdermal absorption agents, and the like, but the dosage form of the drug of the present invention is not limited thereto. Furthermore, it can also be set as a continuous formulation by a well-known technique.

  There are no particular limitations on the type of formulation additive used in the production of the drug of the present invention, and those skilled in the art can appropriately select it. For example, excipients, disintegrants or disintegration aids, binders, lubricants, coating agents, bases, solubilizers or solubilizers, dispersants, suspending agents, emulsifiers, buffers, antioxidants, antiseptics Agents, isotonic agents, pH adjusters, solubilizers, stabilizers, and the like can be used, and the specific components used for these purposes are well known to those skilled in the art.

  Pharmaceutical additives that can be used in the preparation of formulations for oral administration include, for example, excipients such as glucose, lactose, D-mannitol, starch, or crystalline cellulose; carboxymethylcellulose, starch, carboxymethylcellulose calcium, etc. Disintegrating agents or disintegrating aids; binders such as hydroxypropylcellulose, hydroxypropylmethylcellulose, polyvinylpyrrolidone, or gelatin; lubricants such as magnesium stearate or talc; coatings such as hydroxypropylmethylcellulose, sucrose, polyethylene glycol, or titanium oxide Agents: Bases such as petrolatum, liquid paraffin, polyethylene glycol, gelatin, kaolin, glycerin, purified water, or hard fat can be used.

  Examples of pharmaceutical additives that can be used for the preparation of pharmaceutical preparations for injection or infusion include aqueous solutions such as distilled water for injection, physiological saline, propylene glycol, surfactants, etc. Agents or solubilizers; isotonic agents such as glucose, sodium chloride, D-mannitol, glycerin, etc .; use of pharmaceutical additives such as pH regulators such as inorganic acids, organic acids, inorganic bases or organic bases it can.

The agent of the present invention can be administered to mammals such as humans.
The dose of the drug of the present invention should be appropriately increased or decreased according to conditions such as the patient's age, sex, body weight, symptom, and route of administration. Generally, the amount of the active ingredient per adult day In the range of about 1 μg / kg to 1,000 mg / kg, preferably in the range of about 10 μg / kg to 100 mg / kg. The above dose of the drug may be administered once a day, or may be divided into several times (for example, about 2 to 4 times).

  The present invention will be specifically described by the following examples, but the present invention is not limited to the examples.

Example 1 Method of Effect of cPA on Delayed Neuronal Cell Death After Transient Cerebral Ischemia in Rat Hippocampus Experiments were performed on 20 adult male Wistar rats (weight 280-370 g).
The method of cerebral ischemia and histological analysis is basically Kagitani, F., Uchida, S., Hotta, H, and Sato, A (2000) Effects fo nicotine on blood flow and delayed neuronal death fllowing internittent transient ischemia. In rat hippocampus. Jpn. J. Physiol. 50, 585-595, some modifications were made as described below. The animals were anesthetized with halothane (3.5% at the induction of anesthesia: 1.5% during surgery and ischemia). Antibiotics were administered (viccillin 50 mg / kg IM), and an osmotic pump for cyclic phosphatidic acid was implanted subcutaneously in the abdomen. Subsequently, tracheal intubation was performed and breathing was maintained using a ventilator (SN-480-7, Shinano, Tokyo). Rectal temperature and temporal muscle temperature were monitored, and both were maintained at about 37.5 ° C. using a heat pad and lamp (ATB-1100, Nihon Kohden, Tokyo). Bilateral vertebral arteries were permanently ligated and bilateral common carotid arteries were temporarily occluded for 8 minutes. Halosene was cut immediately after the end of transient cerebral ischemia, and the ventilator was removed 15 minutes later.

Pump preparation
5, 50μg / mL rac-2ccPA16: 1 / 0.2% fatty acid-free bovine serum albumin (BSA) -saline (0.9% NaCl), 500 μg / mL rac-2ccPA (16: 1) / 2% BSA-physiology Saline, 50, 500 μg / mL, 5 mg / mL R-cPA18: 1 / 0.2% BSA-saline was prepared, and 200 μl each was injected into Mini osmotic pump model 2000 (alzet, CA). As a control group, a pump into which 0.2% BSA-saline and 2% BSA-saline was injected was prepared. The pump was implanted into the abdominal cavity before ischemic surgery and administered subcutaneously for 5 days.

Experimental group C1 group (comparative example): 0.2% BSA-saline (4 animals)
Group C2 (comparative example): 2% BSA-saline (2 animals)
2ccPA group (present invention): 50 μg / mL 2ccPA16: 1 (18 μg / kg / 5d), (44 nmol / kg / 5d) (4 animals)
cPA group (present invention): 500 μg / mL cPA16: 1 (180 μg / kg / 5d), (400 nmol / kg / 5d) (4 mice)
Reference: 2ccPA16: 1 (molecular weight: 410.22), cPA18: 1 (molecular weight: 440.23)

The structure of 2ccPA16: 1 is as follows.

The structure of cPA18: 1 is as follows.

Observation with Light Microscope On the fifth day after treatment with transient cerebral ischemia, the rat was thoracotomized under somnopentyl deep anesthesia, and transcardiac reflux fixation was performed with heparin-containing physiological saline followed by 10% formalin solution. After storage at 4 degrees for 2 hours, the brain was removed. The slice containing a hippocampus was sliced at a thickness of 3 mm, and the tissue pieces were immersed and fixed in a 10% formalin solution at room temperature for 4 hours. A formalin-fixed sample was embedded in paraffin to prepare a 6 μm-thick paraffin section. A section of 3.3 mm behind Bregma was stained with hematoxylin and eosin, and the left and right hippocampal CAI region pyramidal cells were observed histologically. Calculate the number of viable pyramidal cells per CAI unit length by measuring the number of viable pyramidal cells in the cone cells in the CAI region that show nuclear enrichment and the cell bodies are not atrophied and divide by the CAI length Further, the value of the CI group was set to 1, and the value of each group was represented relatively.

Results Cells causing nuclear enrichment and atrophy of cell bodies were observed in the pyramidal cells of the hippocampal CAI region of C1 and C2 rats, and delayed neuronal cell death was induced by transient cerebral ischemia treatment. It was observed that There was no difference in the pyramidal cell viability due to the difference in BSA concentration. Delayed neuronal cell death was also observed in each of the 2ccPA group and cPA group rats, but in the 2ccPA group, the number of viable cells per CAI unit length was twice as large as that of the C1 group, and the markedly delayed neuron was observed. A cell death inhibitory effect was observed (FIG. 1).

Example 2: Effect of cPA on delayed neuronal cell death after transient cerebral ischemia in rat hippocampus Using the same compounds (2ccPA16: 1 and cPA18: 1) as in Example 1, In a similar experimental system, the effect of cPA on delayed neuronal cell death after transient cerebral ischemia in the rat hippocampus was examined.

The result of histological observation of the pyramidal cells in the hippocampal CAI region is shown in FIG.
In FIG. 2, a in A (Vehicle administration group) and B in B (cPA administration group) indicate CA1 (range where the arrowhead is sandwiched) of the hippocampus (Bregma -3.3 mm).

  FIG. 2A (Vehicle administration group) b and B (cPA administration group) b show the state of cells in the CA1 region. Small and darkly stained cells are cells that have aggregated the nucleus, that is, nerve cells that have undergone delayed cell death. Large round cells are living cells, and the nucleus is small in the center of the cell. I understand that In A (Vehicle administration group) b, the number of dead cells is large and almost no living neurons are found, whereas in B (cPA administration group) b, living cells are mainly used. Only a few cells are dead. It can be seen that the survival rate of neurons in the CA1 region is significantly increased by cPA treatment.

  In FIG. 2, c in A (vehicle administration group) and c in B (cPA administration group) show stained images of GFAP (glial-fibrillary acidic protein). GFAP is a protein constituting an intermediate filament localized in astroglia, and expression of GFAP is increased in neurological diseases such as brain injury and dementia, and is considered to be involved in the severity of cases. In c of A (Vehicle administration group), there are some dark brown cells (anti-GFAP, DAB staining) around dead cells, but in c of B (cPA administration group) around the cells. The darkly stained sites were not found as much as A's c. That is, it is considered that the production of GFAP was suppressed by cPA administration.

  The results of examining the number of viable cells present in rat hippocampal CA1 are shown in FIG. Control (no ischemic) rats were shown to have as many as 420 neurons. On the other hand, in the vehicle (after ischemic treatment) rats, the average number of living neurons is 48, which is about 10%. However, it was shown that the number of living cells was significantly increased in the brains of rats treated with cPA and 2 ccPA. In particular, cPA was found to suppress delayed neuronal cell death after cerebral ischemia in a concentration-dependent manner, with an average of 253 cells surviving and 60% of cells remaining after administration at 18 μg / kg / 5 days. It turns out that it remains alive. Even after the ischemic treatment, it can be said that the survival rate has increased by about 5 times.

Claims (10)

An agent for suppressing delayed neuronal cell death caused by transient cerebral ischemia, comprising cyclic phosphatidic acid, carbacyclic phosphatidic acid or a salt thereof. The chemical | medical agent of Claim 1 whose cyclic phosphatidic acid or carbacyclic phosphatidic acid is a compound shown by Formula (1).
(In the formula, R is a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, or a linear or branched group having 2 to 30 carbon atoms. An alkynyl group, which may contain a cycloalkane ring or an aromatic ring, wherein X and Y each independently represent —O— or —CH ₂ —, wherein X and Y are simultaneously —CH _2; (M is a hydrogen atom or a counter cation.) The chemical | medical agent of Claim 1 or 2 whose X and Y are -O- in General formula (1). In the general formula (1), X or Y is -CH ₂ - is a drug according to claim 1 or 2. In the general formula (1), R is a C ₁₅ H ₂₉ or C ₁₇ H _33, the agent according to any one of claims 1 to 4. Use of cyclic phosphatidic acid, carbacyclic phosphatidic acid or a salt thereof for the manufacture of a drug for suppressing delayed neuronal cell death due to transient cerebral ischemia. The use according to claim 6, wherein the cyclic phosphatidic acid or the carbcyclic phosphatidic acid is a compound represented by the formula (1).
(In the formula, R is a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, or a linear or branched group having 2 to 30 carbon atoms. An alkynyl group, which may contain a cycloalkane ring or an aromatic ring, wherein X and Y each independently represent —O— or —CH ₂ —, wherein X and Y are simultaneously —CH _2; (M is a hydrogen atom or a counter cation.) The use according to claim 6 or 7, wherein in the general formula (1), X and Y are -O-. In the general formula (1), X or Y is -CH ₂ - is Use according to claim 6 or 7. In the general formula (1), R is a C ₁₅ H ₂₉ or C ₁₇ H _33, Use according to any one of claims 6 9.