Therapeutic agent for hypertrophic cardiomyopathy

Abstract

The present invention aims to provide a novel therapeutic agent for hypertrophic cardiomyopathy.　This therapeutic agent for hypertrophic cardiomyopathy has, as an active component thereof, a 5-aminolevulinic acid, an ester thereof, or a salt of the 5-aminolevulinic acid or the ester.

Description

Hypertrophic cardiomyopathy treatment

[0001] The present invention relates to a therapeutic agent for hypertrophic cardiomyopathy.

[0002] Hypertrophic cardiomyopathy (HCM) is defined as a group of diseases characterized by (1) hypertrophy of the left or right ventricular myocardium and (2) decreased left ventricular diastolic function due to cardiac hypertrophy, and is designated as an intractable disease (designated intractable disease 58) (Non-Patent Document 1). Hypertrophic cardiomyopathy is further classified into obstructive (which causes left ventricular outflow tract obstruction) and non-obstructive (which does not). In the former, a left ventricular pressure gradient occurs during systole. Many cases have a family history of autosomal dominant HCM. Clinically, HCM is defined as a maximum left ventricular wall thickness of 15 mm or greater (13 mm or greater if there is a family history of hypertrophic cardiomyopathy) on echocardiography or cardiac MRI. Hypertrophic cardiomyopathy is characterized by elevated left ventricular filling pressure and impaired left ventricular relaxation and distensibility, even in early stages when left ventricular systolic function is normal and the left ventricular diameter is normal (or reduced) (Non-Patent Document 1).

[0003] Most patients with hypertrophic cardiomyopathy are asymptomatic or exhibit only mild symptoms, and in many cases a diagnosis is made after a heart murmur or an abnormal electrocardiogram is found during a medical examination. Symptoms include palpitations and dizziness associated with arrhythmia, difficulty breathing during exercise, and chest tightness. The most serious symptom is fainting.

[0004] As a treatment, strenuous exercise such as competitive sports is prohibited. If symptoms such as arrhythmia are present, they can be improved by administering beta-blockers or verapamil. However, there are no medications available to improve the functional symptom of hypertrophic cardiomyopathy, which is the decreased left ventricular diastolic function, i.e., the decreased left ventricular relaxation rate.

[0005] On the other hand, 5-aminolevulinic acid is a starting material in the porphyrin synthesis pathway, and is used as a photosensitizer in photodynamic therapy (treatment of actinic keratosis, acne, skin cancer, etc.), photodynamic diagnosis (intraoperative diagnosis of brain tumors, transurethral bladder tumor resection, etc.), and also as a plant growth promoter. It has also been reported that 5-aminolevulinic acid, when used in combination with an iron compound, can be used as a hair growth agent (Patent Document 1) and an enzyme-enhanced therapy for mitochondrial disease (Non-Patent Document 2). Furthermore, it has been reported that 5-aminolevulinic acid has the effect of increasing the amount of succinyl-CoA in cardiomyocytes in an animal model of acute myocardial infarction (Patent Document 2).

[0006] International Publication No. WO 2005 / 105022 International Publication No. WO 2020 / 59242

[0007] Guidelines for the Management of Cardiomyopathy (Joint Guidelines of the Japanese Circulation Society and the Japanese Heart Failure Society, 2018 revised edition) Scientific Reports (2019) 9:10549, PMID: 31332208

[0008] An object of the present invention is to provide a novel therapeutic agent for hypertrophic cardiomyopathy.

[0009] Therefore, the present inventors have used cardiomyocytes derived from iPS cells of patients with hypertrophic cardiomyopathy to search for drugs that affect myocardial relaxation rate, which is an indicator of left ventricular diastolic function, and have found that 5-aminolevulinic acid has a strong effect of improving myocardial relaxation rate and also improves left ventricular diastolic function, thereby completing the present invention.

[0010] That is, the present invention provides the following inventions [1] to

[24] . [1] A therapeutic agent for hypertrophic cardiomyopathy, comprising as an active ingredient 5-aminolevulinic acid, an ester thereof, or a salt thereof. [2] An agent for improving left ventricular diastolic function in hypertrophic cardiomyopathy, comprising as an active ingredient 5-aminolevulinic acid, an ester thereof, or a salt thereof. [3] An agent for improving myocardial relaxation rate in hypertrophic cardiomyopathy, comprising as an active ingredient 5-aminolevulinic acid, an ester thereof, or a salt thereof. [4] A therapeutic agent for hypertrophic cardiomyopathy, comprising 5-aminolevulinic acid, an ester thereof, or a salt thereof, and an iron compound. [5] An agent for improving left ventricular diastolic function in hypertrophic cardiomyopathy, comprising 5-aminolevulinic acid, an ester thereof, or a salt thereof, and an iron compound. [6] An agent for improving myocardial relaxation rate in hypertrophic cardiomyopathy, comprising 5-aminolevulinic acid, an ester thereof, or a salt thereof, and an iron compound. [7] Use of 5-aminolevulinic acid, an ester thereof, or a salt thereof for the production of a therapeutic agent for hypertrophic cardiomyopathy. [8] Use of 5-aminolevulinic acid, its ester, or a salt thereof for the manufacture of an agent for improving left ventricular diastolic function in hypertrophic cardiomyopathy. [9] Use of 5-aminolevulinic acid, its ester, or a salt thereof for the manufacture of an agent for improving myocardial relaxation rate in hypertrophic cardiomyopathy.

[10] Use of a combination of 5-aminolevulinic acid, its ester, or a salt thereof with an iron compound for the manufacture of an agent for improving left ventricular diastolic function in hypertrophic cardiomyopathy.

[11] Use of a combination of 5-aminolevulinic acid, its ester, or a salt thereof with an iron compound for the manufacture of an agent for improving left ventricular diastolic function in hypertrophic cardiomyopathy.

[12] Use of a combination of 5-aminolevulinic acid, its ester, or a salt thereof with an iron compound for the manufacture of an agent for improving myocardial relaxation rate in hypertrophic cardiomyopathy.

[13] 5-aminolevulinic acid, its ester, or a salt thereof for use in treating hypertrophic cardiomyopathy.

[14] 5-aminolevulinic acid, its ester, or a salt thereof for use in improving left ventricular diastolic function in hypertrophic cardiomyopathy.

[15] 5-aminolevulinic acid, its ester, or a salt thereof, for use in improving myocardial relaxation rate in hypertrophic cardiomyopathy.

[16] A combination of 5-aminolevulinic acid, its ester, or a salt thereof, and an iron compound, for use in treating hypertrophic cardiomyopathy.

[17] A combination of 5-aminolevulinic acid, its ester, or a salt thereof, and an iron compound, used to improve left ventricular diastolic function in hypertrophic cardiomyopathy.

[18] A combination of 5-aminolevulinic acid, its ester, or a salt thereof, and an iron compound, used to improve myocardial relaxation rate in hypertrophic cardiomyopathy.

[19] A method for treating hypertrophic cardiomyopathy, comprising administering an effective amount of 5-aminolevulinic acid, its ester, or a salt thereof.

[20] A method for improving left ventricular diastolic function in hypertrophic cardiomyopathy, comprising administering an effective amount of 5-aminolevulinic acid, its ester, or a salt thereof.

[21] A method for improving myocardial relaxation rate in hypertrophic cardiomyopathy, comprising administering an effective amount of 5-aminolevulinic acid, its ester, or a salt thereof.

[22] A method for treating hypertrophic cardiomyopathy, comprising administering a combination of 5-aminolevulinic acid, its ester, or a salt thereof, and an iron compound.

[23] A method for improving left ventricular diastolic function in hypertrophic cardiomyopathy, comprising administering a combination of 5-aminolevulinic acid, its ester, or a salt thereof, and an iron compound.

[24] A method for improving myocardial relaxation rate in hypertrophic cardiomyopathy, which comprises administering 5-aminolevulinic acid, an ester thereof, or a salt thereof in combination with an iron compound.

[0011] Use of 5-aminolevulinic acid, its ester, or a salt thereof improves the myocardial relaxation rate, which is an index of left ventricular diastolic function in hypertrophic cardiomyopathy, and enables treatment of hypertrophic cardiomyopathy that improves essential left ventricular diastolic function symptoms of hypertrophic cardiomyopathy.

[0012] 1 shows the myocardial relaxation rate in cardiomyocytes derived from iPS cells of a patient with hypertrophic cardiomyopathy, and the effect of 5-aminolevulinic acid on the relaxation rate. 2 shows the myocardial relaxation rate in a normal control (normal cardiomyocytes), and the effect of 5-aminolevulinic acid on the relaxation rate. 3 shows a comparison of the relaxation rate between cardiomyocytes derived from iPS cells of a patient with hypertrophic cardiomyopathy and normal cardiomyocytes. 4 shows intracellular Ca 2+ The disappearance rate of (= Ca 2+Figure 1 shows the effect of 5-aminolevulinic acid on changes in peak width of Ca-imaging waveforms, which reflects the uptake rate of Ca into the sarcoplasmic reticulum. a. Normal control (n=5), 10 uM 5-aminolevulinic acid (n=6), 30 uM 5-aminolevulinic acid (n=6). b. One example each from the normal control (n=5) and 30 uM 5-aminolevulinic acid (n=6), i.e., the third well out of five examples in the former data set and the fourth well out of six examples in the latter data set, was selected, and three beats from each were plotted with the peak times aligned. Figure 1 shows the effect of 5-aminolevulinic acid on left ventricular diastolic function in a zebrafish cardiomyopathy model.

[0013] The active ingredient of the therapeutic agent for hypertrophic cardiomyopathy of the present invention is 5-aminolevulinic acid, its ester, or a salt thereof. 5-aminolevulinic acid, its ester, or a salt thereof (hereinafter, these may be collectively referred to as 5-aminolevulinic acids) is described in, for example, Patent Document 1 and is publicly known. However, the effect of 5-aminolevulinic acids on improving the relaxation rate in hypertrophic cardiomyopathy is completely unknown.

[0014] Examples of 5-aminolevulinic acid esters include linear, branched, or cyclic alkyl esters having 1 to 24 carbon atoms, which may have a substituent such as a hydroxy group, an alkoxy group, a phenyl group, a benzyl group, or a hydroxymethyl group. Specific examples of 5-aminolevulinic acid esters include 5-aminolevulinic acid methyl ester, 5-aminolevulinic acid ethyl ester, 5-aminolevulinic acid isopropyl ester, 5-aminolevulinic acid hexyl ester, 5-aminolevulinic acid cyclohexyl ester, 5-aminolevulinic acid heptyl ester, 5-aminolevulinic acid octyl ester, 5-aminolevulinic acid nonyl ester, 5-aminolevulinic acid dodecyl ester, 5-aminolevulinic acid hexadecyl ester, 5-aminolevulinic acid benzyl ester, 5-aminolevulinic acid phenethyl ester, 5-aminolevulinic acid phenylpropyl ester, 5-aminolevulinic acid hydroxyethyl ester, and 5-aminolevulinic acid ethoxyethyl ester.

[0015] Examples of salt forms of 5-aminolevulinic acid or esters thereof include inorganic acid salts such as phosphate, hydrochloride, nitrate, and sulfate; organic acid salts such as acetate, propionate, butyrate, valerate, citrate, fumarate, maleate, malate, succinate, oxalate, lactate, tartrate, and glycolate; alkali metal salts such as sodium salt and potassium salt; and alkaline earth metal salts such as calcium salt.

[0016] As shown in the Examples below, 5-aminolevulinic acids have the effect of significantly improving the myocardial relaxation rate, which is an index of left ventricular diastolic function, using cardiomyocytes derived from iPS cells of patients with hypertrophic cardiomyopathy. 2+ The improvement of the uptake function of 5-aminolevulinic acid into the sarcoplasmic reticulum improves the myocardial relaxation rate. Furthermore, 5-aminolevulinic acid improves left ventricular diastolic function in vivo. Therefore, 5-aminolevulinic acids are useful as agents for improving myocardial relaxation rate in hypertrophic cardiomyopathy, agents for improving left ventricular diastolic function in hypertrophic cardiomyopathy, and agents for treating hypertrophic cardiomyopathy.

[0017] Although 5-aminolevulinic acids can be used alone as a therapeutic agent for hypertrophic cardiomyopathy, it is preferable to use 5-aminolevulinic acids in combination with an iron compound from the viewpoint of replenishing iron compounds present in the body and further enhancing the above-mentioned action and effect.

[0018] Here, examples of the iron compound include iron complexes and iron salts, such as heme iron, dextran iron, sodium iron diethylenetriaminepentaacetate, ammonium iron diethylenetriaminepentaacetate, sodium iron ethylenediaminetetraacetate, ammonium iron ethylenediaminetetraacetate, triethylenetetraamine iron, and sodium iron dicarboxymethylglutamate.

[0019] The iron salt may be one or more selected from iron salts of organic acids and iron salts of inorganic acids. Specific examples of the iron salt include ferrous citrate, sodium iron citrate, ammonium iron citrate, iron acetate, iron oxalate, ferrous succinate, sodium iron citrate succinate, ferrous pyrophosphate, ferric pyrophosphate, iron lactate, ferrous gluconate, ferrous formate, ferric formate, potassium ferric oxalate, ferrous sulfate, ferric sulfate, ammonium iron sulfate, ferric carbonate, ferrous chloride, and ferric chloride.

[0020] The content of the iron compound is not particularly limited, but is preferably 0.01 to 1 part by mass, more preferably 0.05 to 1 part by mass, and even more preferably 0.1 to 1 part by mass, per 1 part by mass of the 5-aminolevulinic acids.

[0021] The route of administration of the therapeutic agent of the present invention can be selected from systemic administration and local administration, and from oral and parenteral routes, depending on the disease, symptoms, etc., and a suitable dosage form can be selected depending on the administration method and route, such as oral administration in the form of tablets, pills, capsules, granules, powders, liquids, etc., or parenteral administration in the form of injections (e.g., intravenous injection, intramuscular injection, etc.), suppositories, transdermal agents, nasal agents, inhalants, etc.

[0022] Therapeutic agents for oral administration according to the present invention include solid preparations such as tablets, capsules, powders, and granules. Such preparations are produced by conventional methods by mixing the active ingredient with excipients, lubricants, disintegrants, solubilizers, and the like. Examples of excipients include lactose, cellulose, mannitol, and glucose. Examples of lubricants include magnesium stearate. Examples of disintegrants include sodium carboxymethyl starch, polyvinylpyrrolidone, and croscarmellose sodium. Tablets or pills may be coated with a sugar coating or a gastric or enteric coating agent, if necessary.

[0023] Therapeutic agents for oral administration may be pharmacologically acceptable liquid preparations such as extracts, emulsions, solutions, suspensions, syrups, spirits, or elixirs. Such preparations contain commonly used inert solvents (e.g., purified water, ethanol, etc.) and may further contain solubilizers, wetting agents, suspending agents, sweeteners, flavoring agents, fragrances, buffers (e.g., sodium citrate, etc.), stabilizers, or preservatives.

[0024] Therapeutic agents for parenteral administration include sterile aqueous or non-aqueous solutions, suspensions, or emulsions, such as injections, ointments and lotions, sublingual preparations for oral administration, oral patches, and aerosols or suppositories for nasal administration. Injections can be administered via conventional intravenous or intraarterial administration, as well as subcutaneous, intradermal, or intramuscular injections. Aqueous solvents for injections include, for example, distilled water or physiological saline. Non-aqueous solvents for injections include, for example, propylene glycol, polyethylene glycol, vegetable oils such as olive oil, alcohols such as ethanol, or polysorbate 80 (pharmacopoeia). These formulations may further contain isotonic agents (e.g., sodium chloride, glucose, etc.), preservatives, humectants, emulsifiers, dispersants, stabilizers, pH adjusters (e.g., sodium citrate, sodium acetate, sodium phosphate, etc.), buffers, local anesthetics (e.g., procaine hydrochloride, lidocaine hydrochloride, etc.), or solubilizers. These preparations may be sterilized by, for example, filtration through a bacteria-retaining filter, by incorporating a bactericide, or by irradiation.

[0025] The dosage of the therapeutic agent of the present invention varies depending on the route of administration, symptoms, age, etc., but is generally preferably 10 mg to 1 g of 5-aminolevulinic acid per day for an adult.

[0026] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0027] Example 1 (1) Cardiomyocytes derived from iPS cells of a patient with hypertrophic cardiomyopathy Cardiomyocytes differentiated from iPS cells derived from a patient with hypertrophic cardiomyopathy were purchased, seeded, and cultured, and then administered 5-aminolevulinic acid / sodium ferrous citrate (ALA / SFC). 4M Mycell Cardiomyocytes (MYH7 R403Q) (C1081, cat# 556-3478I) (Cellular Dynamics) were used as cardiomyocytes. As a control, iPS cell-derived cardiomyocytes from a normal individual (Cell Cardiomyocytes (Control) (C1056, cat#551-33491) (Cellular Dynamics) were used. iCell Plating medium (M1001, cat#550-33581) (Cellular Dynamics) was used as the culture medium for cell seeding. iCell Maintenance medium (M1003, cat#557-3359I) (Cellular Dynamics) was used as the culture medium for cell culture.

[0028] (2) Experiments were performed on the above-mentioned cardiomyocytes derived from iPS cells of patients with hypertrophic cardiomyopathy according to the following schedule: Test schedule: Day 1: Cell seeding (cardiomyocytes derived from iPS cells of patients with hypertrophic cardiomyopathy, cardiomyocytes derived from iPS cells of normal individuals). 3 x 10 cells were seeded per well in a 96-well plastic plate (nunc). 4Cells were seeded. Day 15: After measuring the relaxation rate before administration using a Sony SI8000, ALA / SFC was administered at the following doses on the same day. The doses were four groups: 0 μM / 0 μM, 10 μM / 5 μM, 30 μM / 1 μM, and 100 μM / 50 μM ALA / SFC for diseased cardiomyocytes and normal cardiomyocytes. The drug was dissolved in iCell Maintenance medium (M1003) and adjusted to the above concentrations, and then administered by replacing the culture medium in each well with this solution. Relaxation rate measurements were performed three times in total, including before administration on Day 15 and two more times after administration, as described below. Day 18: Second ALA / SFC administration. Day 20: The first relaxation rate after administration was measured using a Sony SI8000, and then the third ALA / SFC administration was performed on the same day. Day 22: The fourth ALA / SFC administration was performed. Day 24: The fifth ALA / SFC administration was performed. Day 26: The second relaxation rate after administration was measured using a Sony SI8000.

[0029] Figure 1 shows the myocardial relaxation rate in cardiomyocytes derived from iPS cells from patients with hypertrophic cardiomyopathy, and the effect of 5-aminolevulinic acid on this relaxation rate. As shown in Figure 1, the relaxation rate in hypertrophic cardiomyopathy was 2.3 ± 0.6 μM ± standard deviation), significantly lower than the relaxation rate in normal cardiomyocytes. Addition of 5-aminolevulinic acid significantly increased the relaxation rate of the hypertrophic cardiomyopathy cardiomyocytes, addressing this decrease in relaxation rate. Figure 2 also shows the myocardial relaxation rate in normal cardiomyocytes (normal myocardial control), and the effect of 5-aminolevulinic acid on this relaxation rate. As shown in Figure 2, the relaxation rate of cardiomyocytes from hypertrophic cardiomyopathy was 4.4 ± 0.6 μM / sec (mean ± standard deviation), and addition of 5-aminolevulinic acid did not increase this relaxation rate over time. A comparison of the relaxation rates in both types of cells is shown in Figure 3. Therefore, it was found that 5-aminolevulinic acids improve the decrease in myocardial relaxation rate in hypertrophic cardiomyopathy and myocardial diastolic function.

[0030] Example 2 The determinant of the rate of cardiac muscle relaxation is the rate of dissociation of myosin and actin. One of the factors that determines the rate of dissociation is the Ca of ATPase present in the longitudinal tubules of the sarcoplasmic reticulum. 2+Therefore, using the cardiomyocytes derived from iPS cells of hypertrophic cardiomyopathy (HCM) patients, we investigated the effect of 5-aminolevulinic acid on the intracellular Ca uptake. 2+ The disappearance rate of (= Ca 2+ The peak width of the Ca-imaging waveform, which reflects the rate of Ca uptake into the sarcoplasmic reticulum, was measured.

[0031] (1) iPS cell-induced cardiomyocytes as a hypertrophic cardiomyopathy (HCM) model: Cardiomyocytes induced from iPS cells derived from a patient with hypertrophic cardiomyopathy (obtained from CDI Co.) were seeded onto a 96-well plate under the following conditions: the cell density was 3 × 10 4 The seeding medium was iPs Cardiomyocyte Plating Medium (IPMM; M1001, cat#550-33581) (Cellular Dynamics) manufactured by CDI Co., Ltd., and iPs Cardiomyocyte Maintenance Medium (ICMM; M1003, cat#557-3359I) was used for long-term culture (100 microliters / well). Long-term culture (one month) was performed at 37°C and 7% CO2. Calcium imaging measurements were performed on days 7, 14, and 21 after seeding. Calcium fluorescence measurement reagents were EarlyTox or Cal520 at final concentrations of 10 nM or 50 nM, respectively. 5-aminolevulinic acid was added to the culture medium on day 7 after seeding, and was administered at each concentration continuously until the imaging measurement days on days 14 and 21.

[0032] (2) Conditions for Fluorescence Calcium Imaging Measurements: A Yokogawa CQ1 Image Cytometer was used as the measurement device for High Content Analysis, with excitation light at 488 nm and fluorescence at 500-550 nm (spinning disk confocal with microlens array). Measurement parameters: Measurement fluorescence filter; approximately 500-550 nm transmission filter cube (BandPass: 50 nm), 20x dry objective lens (UPLSAPO 20x), confocal pinhole 50 μm, sCMOS 2560 × 2160 pixels 16.6 × 14.0 mm, acquired image size 500 × 500, video acquisition time resolution 20 fps. Stage environment: 37 °C, 5% CO2, humidified. The image data was acquired and transferred to an external device using analysis software, Cell Pathfinder.

[0033] (3) Data Analysis Method The obtained image data was digitized over time to obtain a fluorescence waveform of the fluorescence intensity across the entire screen. These numerical data were subjected to waveform analysis using Web Finder, a waveform analysis software. The parameters calculated from the waveform were the line width (seconds) at 10%, 20%, 30%, 50%, 70%, and 90% of the waveform height, the length of the interval between angular waves (seconds), and the fluorescence intensity (ΔF). The results are shown in Figure 4. As is clear from Figure 4, the addition of 5-aminolevulinic acid clearly reduced the peak width at 50% of the waveform height, and the Ca 2+ It was found that the uptake function of α-glucan into the sarcoplasmic reticulum was improved.

[0034] Example 3 The effect of 5-aminolevulinic acid on a zebrafish cardiomyopathy model was investigated. (1) Creation of a zebrafish cardiomyopathy model (cardiac troponin T knockdown (tnnt2a KD)) A synthetic nucleic acid morpholino antisense oligo (MO) that inhibits the translation of zebrafish cardiac troponin T (tnnt2a) was used. The target sequence of the tnnt2a-MO used to create this cardiomyopathy model was 5'-CATGTTTGCTCTGATCTGACACGCA-3' (SEQ ID NO: 1), and the target sequence of the Standard control MO (Control-MO) used as a negative control was 5'-CCTCCTACCTCAGTTACAATTTATA-3' (SEQ ID NO: 2). Both MOs were produced by GeneTool. Furthermore, standard control MO (Lis-MO) labeled with the red fluorescent substance Lissamine at the 3' end was used as an internal standard. Powdered MO was diluted to 1 mM with nuclease-free water to prepare a stock solution, and the final concentrations of tnnt2a-MO and Control-MO were adjusted to 1.2 μM, and the final concentration of Lis-MO was adjusted to 50 μM with nuclease-free water to prepare a working solution for microinjection. A glass needle was prepared by processing a glass capillary (GD-1, Narishige) using a puller (PC-100, Narishige). The needle was filled with MO working solution and connected to the injection holder of a DNA injection set (IM-400, 0.2LE-8SBZN, MMO-220C, M-152, GJ-1, IP, Narishige). Adult zebrafish (RIKEN-WT) were naturally mated to obtain fertilized eggs from the same parent. Approximately 3 nL of working solution was injected into each 1-4 cell stage fertilized egg. After microinjection, the fertilized eggs were transferred to a 10 cm dish (sterilized Azunol Petri dish) and grown in E2 Medium, a standard rearing solution, in an incubator set at 28°C.

[0035] (2) The effects of 5-aminolevulinic acid were investigated using the following experimental schedule. DAY 0 (7-8 hours after fertilization): Approximately 50 embryos were transferred to a new 10 cm dish, and E2 Medium containing 0.003% 1-phenyl-2-thiourea (P7629, Sigma-Aldrich) to inhibit melanin pigment production was used as the rearing solution. The experimental group was prepared with ALA / SFC at 100 μM / 50 μM, while the control group was prepared with ALA / SFC at 0 μM / 0 μM. DAY 1: ALA / SFC was administered for the second time. DAY 2: ALA / SFC was administered for the third time. Day 3: Without anesthesia, the individual was mounted on a 3 cm glass-bottom dish (Greiner) using 1% low-melting-point agarose gel, and cardiac imaging was performed under bright field conditions using a 20x objective lens installed on an inverted microscope CKX53 (Olympus), and video images were obtained.

[0036] (3) Image analysis was performed using ImageJ as follows. The acquired video was converted into sequence images, and the outline of the ventricle in each frame was recorded as the Region of Interest (ROI). Next, the Fit-to-Ellipse algorithm was used to measure the major and minor axes of an ellipse approximating the ROI on each sequence image. The volume of the spheroid in each sequence image was calculated as the ventricular volume, and the Peak Filling Rate (PFR: diastolic function) was measured from the rate of change in the obtained ventricular volume. The results are shown in Figure 5. As is clear from Figure 5, administration of 5-aminolevulinic acid was found to improve left ventricular diastolic function in an in vivo cardiomyopathy model.

Claims

1. A therapeutic agent for hypertrophic cardiomyopathy comprising 5-aminolevulinic acid, its ester or a salt thereof as an active ingredient.

2. An agent for improving left ventricular diastolic function in hypertrophic cardiomyopathy, comprising 5-aminolevulinic acid, an ester thereof or a salt thereof as an active ingredient.

3. An agent for improving myocardial relaxation rate in hypertrophic cardiomyopathy, comprising 5-aminolevulinic acid, an ester thereof or a salt thereof as an active ingredient.

4. A therapeutic agent for hypertrophic cardiomyopathy comprising 5-aminolevulinic acid, an ester thereof or a salt thereof, and an iron compound.

5. An agent for improving left ventricular diastolic function in hypertrophic cardiomyopathy, comprising 5-aminolevulinic acid, an ester thereof or a salt thereof, and an iron compound.

6. An agent for improving myocardial relaxation rate in hypertrophic cardiomyopathy, comprising 5-aminolevulinic acid, an ester thereof or a salt thereof, and an iron compound.