Pharmaceutical composition for reflex syncope

Abstract

To provide a pharmaceutical composition for the prevention and / or treatment of reflex syncope.SOLUTION: Provided is a pharmaceutical composition for the prevention or treatment of reflex syncope, comprising a neurokinin-1 receptor antagonist (NK1A) as an active ingredient.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a pharmaceutical composition for the prevention or treatment of reflex syncope.

[0002] Reflex syncope is a type of fainting caused by a temporary decrease in blood flow to the brain, and accounts for many cases of fainting without a clear causative disease. Reflex syncope is a general term for situational syncope, which occurs in specific situations such as urination, defecation, coughing, swallowing, after eating, and when drawing blood, vasovagal syncope, which includes fainting caused by emotional stress such as fear, pain, and startle, and fainting immediately after exercise, and carotid sinus syncope. Reflex syncope is a type of fainting that can occur suddenly depending on the location and situation, and it is said that reflex syncope is the most common cause of fainting while driving a car, accounting for 30 to 37% of cases. Therefore, depending on the location or situation in which reflex syncope occurs, it may cause complications such as fractures, subdural hematomas, and injuries from car accidents. However, currently there is no established treatment for reflex syncope, and treatment strategies are determined according to the individual pathology.

[0003] It is known that reflexes related to the large intestine cause disruptions in the autonomic nervous system, including enhanced vagus nerve activity, but it has been reported that colon-mediated reflexes occur during defecation syncope (Non-Patent Document 1). In reflex syncope, mechanoreceptors for stimuli differ for each type of syncope, but the reflex pathways of the autonomic nervous system are almost identical (Non-Patent Document 2). The afferent vagus nerve terminates in the nucleus of the solitary tract and projects first to the caudal ventrolateral medulla. The rostral ventrolateral medulla, which integrates the movements of the cardiovascular system, then receives inhibitory projections from the caudal ventrolateral medulla (Non-Patent Document 3 and Non-Patent Document 4). These central pathways are thought to be involved in the expression of lowered blood pressure and bradycardia due to enhanced vagus nerve activity and inhibition of sympathetic nerves. However, there are still many unknowns about how the central nervous system is involved in reflex syncope, including situational syncope, and currently there are no treatments or medications for reflex syncope that target the central nervous network. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Bae et al., Pacing Clin Electrophysiol. 35:341-347 2012. doi:10.1111 / j.1540-8159.2011.03290.x [Non-Patent Document 2] Ballantyne et al., Auton Neurosci. 2021 Dec;236:102904. doi: 10.1016 / j.autneu.2021.102904. Epub 2021 Nov 4. PMID: 34763249. [Non-Patent Document 3] Reis et al., Clin. Exp. Hypertens. A6(1-2), 221-241 1984. doi:10.3109 / 10641968409062562 [Non-Patent Document 4] Holstein et al., Front. Neurol. 3:4 2012, doi:10.3389 / fneur.2012.00004 [Non-Patent Document 5] Maggi et al., Gen. Pharmacol. 26:911-944 1995. doi:10.1016 / 0306-3623(94)00292-u [Non-Patent Document 6] Mistrova et al., Neuropeptides 58:41-51 2016. doi:10.1016 / j.npep.2015.12.005 [Non-Patent Document 7] Wang et al., J. Comp. Neurol. 434:128-146 2001. doi:10.1002 / cne.1169 [Non-Patent Document 8] Li et al., J. Physiol. Sci. 56:153-156 2006. doi:10.2170 / physiolsci.RP001106 [Non-Patent Document 9] Traub et al., Pain 49:393-403 1992. doi:10.1016 / 0304-3959(92)90247-9 [Non-Patent Document 10] Ness and Gebhart, Brain Res. 450:153-169 1988. doi:10.1016 / 0006-8993(88)91555-7 [Non-Patent Document 11] Traub et al., Brain Res. 701:175-182 1995. doi:10.1016 / 0006-8993(95)00990-5 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above circumstances, an objective of the present invention is to provide a pharmaceutical composition for the prevention and / or treatment of reflex syncope, such as situational syncope, vasovagal syncope, and carotid sinus syndrome. [Means for solving the problem]

[0006] As mentioned above, in syncope classified as reflex syncope, the mechanoreceptors for stimuli differ depending on the type of syncope, so the afferent pathways are different, but the efferent pathways from the nucleus tractus solitarius in the medulla oblongata, which is the reflex center, are thought to be almost the same (Non-Patent Document 2). Therefore, the present inventors have focused on the neural activity in the efferent pathways from the nucleus tractus solitarius when reflex syncope occurs and have conducted extensive research. Neurokinin-1 (NK) is a member of the seven-transmembrane G protein-coupled receptor family. 1NK receptors play a role in various physiological functions and the pathophysiology of diseases (Non-Patent Document 5), and are also involved in the regulation of the autonomic nervous system (Non-Patent Document 6). 1 Receptor immunoreactive neurons have been found in the ventral part of the nucleus ambiguus, the nucleus tractus solitarii, and the ventromedial medulla oblongata, as well as in the rostral compact portion of the nucleus ambiguus (NPL 7). 1 Receptor immunoreactivity has been found in many types of ventral medulla neurons. 1 We conducted research based on the idea that the receptor may be involved in the function of the central autonomic nervous system and that its antagonist may have the function of alleviating reflex syncope.

[0007] In a rat model, colonic distension induces a vagal reflex through afferent vagal stimulation (Non-Patent Document 8). Colonic distension also induces c-Fos expression in the lumbosacral spinal cord as a noxious visceral stimulus (Non-Patent Document 9). Furthermore, such c-Fos expression is suppressed by anesthesia and analgesics (Non-Patent Documents 10 and 11). The present inventors used colonic distension in rats as a model of situational syncope and investigated the effect of NK on the vagal reflex. 1 We investigated the effects of the receptor antagonist, which inhibited the decrease in blood pressure caused by colonic stretch and reduced the number of c-Fos immunostaining positive cells in the caudal ventrolateral medulla induced by colonic stretch. The present invention has been completed based on the above findings.

[0008] That is, the present invention includes the following (1) to (5). (1) Neurokinin-1 receptor antagonist (NK 1 A pharmaceutical composition for preventing or treating reflex syncope, comprising A) as an active ingredient. (2) The pharmaceutical composition described in (1) above, wherein the reflex syncope is vasovagal syncope, carotid sinus syncope or situational syncope. (3) The pharmaceutical composition according to (2) above, wherein the vasovagal syncope is emotional syncope, syncope caused by standing / sitting for a long time, or syncope immediately after exercise. (4) The pharmaceutical composition according to (2) above, wherein the situational syncope is cough syncope, swallowing syncope, defecation syncope or micturition syncope. (5) The above-mentioned NK 1 A is Aprepitant, Fosaprepitant, Netupitant, Fosnetupitant, Casopitant, Cizolirtine, Maropitant, Nolpitantium, Vofopitant, Ezlopitant, Figo The pharmaceutical composition according to any one of (1) to (4) above, which is figopitant, vestipitant, burapitant, befetupitant, rolapitant, serlopitant, tradipitant, immunopitant, elinzanetant, EU-C-001, orvepitant, SDZ-NKT-343, RP-67580, L-741671, FR-113680, FK224, FK888, CP-99994, CP-96345 or CGP-49823. In this specification, the symbol "~" indicates a numerical range including the values ​​on either side of it. Effect of the Invention

[0009] The pharmaceutical composition of the present invention exhibits excellent preventive and therapeutic effects against reflex syncope. [Brief description of the drawings]

[0010] [Figure 1]Figure 1 shows a typical hemodynamic response of a rat subjected to colonic distension (distension at 80 mmHg). Colonic distension was performed for a total of 60 seconds, with the pressure gradually increased over 10 seconds (dotted period) until the target pressure was reached, which was then maintained for 40 seconds (solid period), and then the pressure was decreased over 10 seconds (dotted period). [Diagram 2] Figure 2 shows the change in mean blood pressure due to colonic distension. The graph shows the mean blood pressure (MAP) after colonic distension at each pressure (40 mmHg, 60 mmHg, 80 mmHg). The results are from groups that received saline (CRD) or fosaprepitant (30 mg / kg; CRD+NK1A) intraperitoneally 40 minutes before colonic distension. Values ​​are shown as mean ± standard deviation. Comparison of values ​​between groups was performed using Welch's t-test (p-value). [Diagram 3] Figure 3 shows the results of investigating the activation of the blood pressure control center (area postrema and nucleus tractus solitarius) by colonic stretch. The figure shows the distribution of c-Fos immunostained positive cells in the area postrema (AP) and nucleus tractus solitarius (NTS) in the groups with colonic stretch (CRD and CRD+NK1A) and without colonic stretch (control). [Figure 4] Figure 4 shows the results of investigating the activation of the blood pressure control center (caudal ventrolateral medulla) by colonic stretching. The figure shows the distribution of c-Fos immunostained positive cells in the caudal ventrolateral medulla (CVLM), nucleus ambiguus (Amb), and lateral reticular nucleus (LRN) in the groups with colonic stretching (CRD and CRD+NK1A) and without colonic stretching (control). [Diagram 5] Figure 5 shows the number of c-Fos immunostained positive cells that appeared in the blood pressure control center after colonic stretch. The numbers of c-Fos immunostained positive cells in the nucleus tractus solitarii (A) and the caudal ventrolateral medulla (B) in the colonic stretch group (CRD and CRD+NK1A) and the group without colonic stretch (control) are shown. Values ​​are shown as mean ± standard deviation. Comparisons between groups were performed using Tukey's multiple comparison test (p value). NTS; nucleus tractus solitarii; CVLM; caudal ventrolateral medulla. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present invention will be described. Note that, when written as "the present embodiment", it refers to all or any of the embodiments described in this specification unless otherwise specified. The first embodiment is NK 1 Receptor antagonist (NK 1 The present invention relates to a pharmaceutical composition for preventing or treating reflex syncope (or a drug for improving reflex syncope), which comprises as an active ingredient, The term "antagonist" used in this embodiment refers to an NK 1 It binds reversibly or irreversibly to the receptor and acts as an agonist (NK 1 It is a substance that interacts with a receptor and activates the original function of the receptor, and examples of such substances include substances belonging to the tachykinin family, such as substance P, neurokinin A, and neurokinin B. 1Examples of A include, but are not limited to, aprepitant, fosaprepitant, netupitant, fosnetupitant, casopitant, cizolirtine, maropitant, nolpitantium, bofopitant, ezlopitant, figopitant, vestipitant, burapitant, and befetupitant. Examples of the anti-inflammatory drugs include fetupitant, rolapitant, serlopitant, tradipitant, immunopitant, elinzaetant, EU-C-001, orvepitant, SDZ-NKT-343, RP-67580, L-741671, FR-113680, FK224, FK888, CP-99994, CP-96345, and CGP-49823. Preferred are aprepitant, fosaprepitant, and maropitant, and more preferred are fosaprepitant and maropitant.

[0012] In this embodiment, "reflex syncope" refers to syncope caused by a transient decrease in blood flow to the brain, which occurs when the mechanoreceptors for stimuli differ depending on the type of syncope, and therefore the afferent pathway (pathway for transmitting information from the periphery to the center) differs, but the efferent pathway (pathway for transmitting information from the center to the periphery) from the nucleus tractus solitarius in the medulla oblongata, which is the reflex center, follows almost the same path. Known examples of reflex syncope include vasovagal syncope, carotid sinus syncope, and situational syncope. Furthermore, vasovagal syncope includes emotional syncope, syncope caused by standing / sitting for a long time, postural / gravitational syncope, syncope immediately after exercise, etc., while situational syncope includes cough syncope, swallowing syncope, defecation syncope, micturition syncope, etc. (see Non-Patent Document 2, etc.).

[0013] The pharmaceutical composition according to the present embodiment (including a drug for improving reflex syncope) contains the active ingredient NK 1 In addition to A, it is preferable that the pharmaceutical composition according to the present embodiment contains one or more formulation additives. 1 In addition to A, other known ingredients effective for the prevention or treatment of the disease to be prevented or treated may be included.

[0014] The subjects to which the pharmaceutical composition of this embodiment is administered include not only humans but also non-human mammals, for example, pet animals such as dogs, cats, and rabbits, and livestock animals such as cows, pigs, sheep, and horses.

[0015] The dosage form of the pharmaceutical composition according to the present embodiment includes tablets, capsules, granules, powders, syrups, suspensions, suppositories, and injections. These preparations are prepared according to conventional methods. Liquid preparations may be dissolved or suspended in water or other suitable solvents when used. Tablets and granules may be coated by known methods. Injections are prepared by dissolving the active ingredient in water, etc., but may be dissolved in saline or glucose solution as necessary, and buffers and preservatives may be added.

[0016] Preparations for oral or parenteral administration are provided in any formulation form. The formulation form may be, for example, a pharmaceutical composition for oral administration in the form of granules, fine granules, powders, hard capsules, soft capsules, syrups, or liquids, or a pharmaceutical composition for parenteral administration in the form of an injection, drip infusion, suppository, or the like for intravenous, intramuscular, or subcutaneous administration. Injections and drip infusions may be prepared in a powder form, such as a freeze-dried form, and may be dissolved in an appropriate aqueous medium, such as physiological saline, when used.

[0017] The type of formulation additive used in the production of the pharmaceutical composition according to this embodiment, the ratio of the formulation additive to the active ingredient, or the production method of the pharmaceutical composition can be appropriately selected by a person skilled in the art depending on the form of the pharmaceutical composition. As the formulation additive, an inorganic or organic substance, or a solid or liquid substance can be used, and generally, it can be blended at between 1% by weight and 90% by weight of the active ingredient. Specific examples of formulation additives include lactose, glucose, mannitol, dextrin, cyclodextrin, starch, sucrose, magnesium aluminometasilicate, synthetic aluminum silicate, sodium carboxymethylcellulose, hydroxypropyl starch, calcium carboxymethylcellulose, ion exchange resins, methylcellulose, gelatin, gum arabic, hydroxypropylcellulose, hydroxypropylmethylcellulose, polyvinylpyrrolidone, polyvinyl alcohol, light anhydrous silicic acid, magnesium stearate, talc, tragacanth, bentonite, veegum, titanium oxide, sorbitan fatty acid esters, sodium lauryl sulfate, glycerin, fatty acid glycerin esters, purified lanolin, glycerogelatin, polysorbate, macrogol, vegetable oils, wax, liquid paraffin, white petrolatum, fluorocarbons, nonionic surfactants, propylene glycol, and water.

[0018] To prepare a solid preparation for oral administration, the active ingredient is mixed with excipients such as lactose, starch, crystalline cellulose, calcium lactate, anhydrous silicic acid, etc. to prepare a powder, or further, if necessary, a binder such as sucrose, hydroxypropylcellulose, polyvinylpyrrolidone, or a disintegrant such as carboxymethylcellulose, calcium carboxymethylcellulose, etc. is added and wet or dry granulated to prepare a granule. To prepare tablets, these powders and granules may be tableted as is or with the addition of a lubricant such as magnesium stearate or talc. These granules or tablets may be coated with an enteric base such as hydroxypropylmethylcellulose phthalate or methacrylic acid-methyl methacrylate polymer to prepare an enteric coated preparation, or coated with ethylcellulose, carnauba wax, hardened oil, etc. to prepare a sustained release preparation. To prepare capsules, the powders or granules may be filled into a hard capsule, or the active ingredient may be dissolved in glycerin, polyethylene glycol, sesame oil, olive oil, etc. and then coated with a gelatin membrane to prepare a soft capsule.

[0019] To produce an injection, the active ingredient is dissolved in distilled water for injection, if necessary, together with a pH adjuster such as hydrochloric acid, sodium hydroxide, lactose, lactic acid, sodium, sodium monohydrogen phosphate, sodium dihydrogen phosphate, etc., and an isotonicity agent such as sodium chloride, glucose, etc., and then sterile filtered and filled into an ampoule, or it may be further added with mannitol, dextrin, cyclodextrin, gelatin, etc., and then vacuum lyophilized to produce an injection that is dissolved when used. Also, the active ingredient may be added with lecithin, polysorbate 80, polyoxyethylene hydrogenated castor oil, etc., and emulsified in water to produce an emulsion for injection.

[0020] To prepare a rectal preparation, the active ingredient may be dissolved by wetting together with a suppository base such as cacao butter, tri-, di-, or monoglyceride of fatty acid, or polyethylene glycol, and then poured into a mold and cooled; alternatively, the active ingredient may be dissolved in polyethylene glycol, soybean oil, or the like, and then coated with a gelatin film.

[0021] The dosage and number of administrations of the pharmaceutical composition according to the present embodiment are not particularly limited, and can be appropriately selected by the doctor or veterinarian depending on the type of reflex syncope, the purpose of prevention or treatment, the weight and age of the patient, and other conditions. When the subject of administration is a human, the daily oral dose for an adult is generally about 0.01 to 1000 mg (weight of active ingredient), and can be administered once a day or in divided doses several times a day, or every few days. When used as an injection, it is desirable to administer a daily dose of 0.001 to 100 mg (weight of active ingredient) to an adult continuously or intermittently. The dosage per body weight is, for example, 1 to 50 mg / kg, preferably 2 to 30 mg, and more preferably 2 to 20 mg, whether it is administered orally or as an injection. When administered to a mammal other than a human, the dosage per body weight is preferably the same as that of a human.

[0022] The medicament or pharmaceutical composition according to the present embodiment can be prepared as a sustained release formulation, such as an implant and a microencapsulated delivery system, using a carrier that can prevent immediate removal from the body. Such carriers can be biodegradable, biocompatible polymers, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid. Such materials can be easily prepared by those skilled in the art. Also, suspensions of liposomes can be used as pharma-ceutically acceptable carriers. Liposomes can be prepared as lipid compositions, including, but not limited to, phosphatidylcholine, cholesterol, and PEG-derivatized phosphatidylethanol (PEG-PE), by passing through a filter of appropriate pore size to a size suitable for use, and purified by reverse phase evaporation.

[0023] The pharmaceutical composition according to this embodiment may be provided in the form of a kit together with instructions on the administration method and the like. The pharmaceutical composition contained in the kit is provided in an appropriate container. The container must be made of a material that allows the activity of the components of the pharmaceutical composition contained therein to be effectively maintained for a long period of time, that does not allow the components to be adsorbed to the inside of the container, and that does not cause the components to deteriorate within the container. Instructions for use may also be attached to the kit. The instructions for use of the kit may be printed on paper or the like, or may be stored in an electromagnetically readable medium and provided to the user.

[0024] The second embodiment relates to a method for the preparation of a pharmaceutical composition for the prevention or treatment of reflex syncope (or a drug for improving reflex syncope), comprising administering to the subject a compound comprising the compound of formula (I) or (II) a compound having the formula (I) and a compound having the formula (II ... 1 The use of A for producing the pharmaceutical composition. 1 For information on how to use A, etc., please refer to the explanation of the first embodiment.

[0025] The third embodiment is NK 1 A method for preventing or treating reflex syncope by administering to a subject a pharmaceutical composition containing A as an active ingredient. Furthermore, the prevention or treatment of reflex syncope also includes an effect of improving reflex syncope. Subjects for the prevention or treatment of reflex syncope include not only humans but also non-human mammals, for example, pet animals such as dogs, cats, and rabbits, and livestock animals such as cows, pigs, sheep, and horses.

[0026] When this specification is translated into English and includes the singular words "a," "an," and "the," it is intended to include the plural as well as the singular, unless the context clearly indicates otherwise. Also, in this specification, "about" or "to the extent" refers to a numerical range of ±10%. The present invention will be further described below with reference to examples. However, these examples are merely illustrative of embodiments of the present invention and are not intended to limit the scope of the present invention. EXAMPLES

[0027] I. Animal Examples I-1. Experimental Methods and Materials I-1-1. Animals Animal care and handling were carried out in accordance with the Azabu University Animal Experiment Guidelines. All experimental procedures were approved by the Azabu University Animal Experiment Committee (approval number: 191205-8). Eighteen Wistar rats (Japan SLC) weighing 250-350 g were used in the experiment. The rats were kept in single cages (225 mm) under a 12-h light-dark cycle (light period from 7:00 to 19:00) in an environment with a temperature of 23 ± 2°C and humidity of 60 ± 10%. 3 ×338 mm 3 ×140mm 3 ) in a cage. They were allowed to drink water and regular pelleted food (CREA Rodent Diet CE-2R; CREA Japan) ad libitum during the cage. All animal experiments were initiated after an acclimation period of at least one week. Eighteen rats were randomly divided into the following groups. The colonic distension group was administered saline (CRD group) or a neurokinin-1 receptor antagonist (CRD+NK group) before the start of the experiment. 1 A control group without colonic distention was also prepared for histological evaluation.

[0028] I-1-2. Colonic extension Colonic distention was performed as previously reported (Li et al., J. Physiol. Sci. 56:153-156 2006. doi:10.2170 / physiolsci.RP001106) with some modifications. Rats were anesthetized by intraperitoneal administration of 1.2 g / kg urethane. In preliminary experiments, it was difficult to stabilize hemodynamics with other anesthesia methods, so we determined that anesthesia with urethane was very important to capture slight fluctuations in hemodynamics. The preparation, use, and storage of urethane were performed according to the guidelines (Guidelines for Urethane, UC San Diego, 20161). In advance of the experiment, a catheter was placed in the femoral artery of the rats to record mean blood pressure and heart rate. In addition, the rats were intubated and body temperature was maintained with a heating mat and blanket. During the experiment, the rats were maintained in a supine position. After the preparation was completed, 30 mg / kg of fosaprepitant meglumine (PROEMEND®, Ono Pharmaceutical Co., Ltd.) (prodrug of aprepitant) or saline was intraperitoneally administered to rats in each group. The total dose of the drug was set to 10 ml / kg by diluting with saline. The dose of fosaprepitant was set based on a previous report (Prasoon et al., Indian J. Pharmacol. 48:394-398 2016. doi:10.4103 / 0253-7613.186198). Colonic distension was started 40 minutes after drug administration. Colonic distension was performed by inserting a 2.0 cm diameter air-filled balloon made using the finger part of a latex glove into the anus. Specifically, the tip of the balloon was placed at a depth of 6.0 cm from the anus. Colonic distension was performed by inflating the balloon using an air-filled syringe, and the pressure was monitored using a pressure transducer (DX-300, Nihon Kohden). The pressure transducer was connected to the balloon via a T-shaped cock. The rectal distension procedure was performed by applying balloon pressures of 40 mmHg, 60 mmHg, and 80 mmHg for 60 seconds, with an interval of approximately 5 minutes between each distension. The pressure was converted to a digital signal by an analog-to-digital converter for analysis.The maximum change in mean blood pressure during colonic distensions was compared with the pre-stimulation control values.

[0029] I-1-3. Fixation, sectioning and staining of tissues After colonic distention, rats were perfused transcardially with 100 ml of 10 mM phosphate-buffered saline (37°C), followed by perfusion with 4% paraformaldehyde in 0.1 M phosphate-buffered saline (pH 7.4) (500 ml). Brains were removed and harvested at 4° C. for 24 hours, and then stored at 4° C. in phosphate-buffered saline until used for histological examination. Tissue sections were prepared by cutting the entire medulla oblongata into serial sections 50 μm thick using a vibratome (Microslicer DTK-1000, Dosaka EM). Endogenous peroxidase was inactivated in 10 mM phosphate-buffered saline containing 3% hydrogen peroxide for 20 min, followed by washing in phosphate-buffered saline and immersion of the sections in blocking solution (phosphate-buffered saline containing 1% normal goat serum) for 1 h.

[0030] The avidin-biotinylated peroxidase complex method was performed as previously described (Pete et al., Respir. Physiol. Neurobiol. 130:265-274 2002. doi:10.1016 / s0034-5687(02)00013-0; Kakiuchi et al., Eur. J. Pharmacol. 723:1-6 2014. doi:10.1016 / j.ejphar.2013.11.038) with modifications. First, sections were incubated with primary antibody (rabbit anti-c-Fos polyclonal antibody; Santa Cruz Biotechnology) diluted 1:10,000 for 24 h at room temperature. Next, after washing the primary antibody with phosphate-buffered saline, the sections were incubated in secondary antibody (biotinylated IgG; Vector Laboratories) diluted in blocking solution (1:200) for 90 min. After washing the secondary antibody with phosphate-buffered saline, the sections were subjected to avidin / biotin-immunoperoxidase reaction using a Vectastain ABC kit (Vector Laboratories). Immunoreactive activity was visualized by incubating the sections with 0.02% 3,3'-diaminobenzidine containing 0.01% hydrogen peroxide for 10 min. Nickel chloride was added to the hydrogen peroxide reaction mixture to obtain a purple-black reaction product. The stained sections were mounted on poly-L-lysine-coated slides to observe the immunostained positive cells.

[0031] I-1-4. Microscope observation The area postrema and nucleus tractus solitarius were located according to a brain atlas (Paxinos and Watson, (1998). The rat brain in stereotaxic coordinates. Academic Press) as previously reported (Horn et al., Auton. Neurosci. 132 (1-2):44-51 2007. doi:10.1016 / j.autneu.2006.09.005). The caudal ventrolateral medulla is located in the region surrounding the lateral reticular nucleus and caudal to the nucleus ambiguus (Wang et al., J. Comp. Neurol. 434:128-146 2001. doi:10.1002 / cne.1169;Stornetta et al., J. Comp. Neurol. 512:373-383 2009. doi:10.1002 / cne.2189). Images of brain regions containing c-Fos-immunostained positive cells were digitized using a Canon EOS Kiss digital camera (Canon) and magnified appropriately depending on the size and structure of each region. In addition, the number of c-Fos-immunostained cells in the area postrema, nucleus of the solitary tract, and ventrolateral medulla were counted using NIH ImageJ software (National Institutes of Health). Observers were blinded to the treatment groups of each animal and performed cell counts.

[0032] I-1-5. Data Analysis Statistical analysis of the data was performed using R software (R version 4.0.4; R Foundation for Statistical Computing). After using the Shapiro-Wilk test to assess normality, values ​​are presented as mean ± standard deviation. Paired t-tests were used to compare blood pressure changes before and after stimulation of colonic distension. Welch's t-tests were used for comparison between groups. Tukey's multiple comparisons test was used to compare the total number of c-Fos immunostained positive cells in the area postrema, nucleus tractus solitarii, and caudal lateral medulla oblongata. Differences between values ​​were considered significant when p < 0.05.

[0033] I-2. Results I-2-1. Blood pressure changes due to colonic stretch Colonic distension was performed at distension pressures of 40, 60, and 80 mmHg. The pressure was gradually increased over 10 seconds until the distension pressure reached the desired value, the desired distension pressure was maintained for 40 seconds, and the distension pressure was decreased over 10 seconds, for a total of 60 seconds of distension. Figure 1 shows the time course of mean blood pressure and heart rate when the desired colonic distension pressure was set at 80 mmHg. The mean blood pressure began to decrease immediately after the start of colonic distension and gradually recovered to the original blood pressure when distension was released. The CRD group (group that underwent colorectal distension (CRD)) and CRD+NK 1 Group A (in addition to colonic distention, NK was administered before CRD) 1 The heart rates before the start of colonic distension in the CRD group and the CRD+NK group were 431 ± 40 bpm and 419 ± 30 bpm, respectively (p = 0.566), and the mean blood pressures were 89 ± 11 mmHg and 84 ± 11 mmHg, respectively (p = 0.466). In the CRD group, the mean blood pressure decreased significantly with increasing distension pressure. 1 In group A, the degree of decrease in mean blood pressure due to a stimulation of 80 mmHg was significantly smaller than in the CRD group (Figure 2). These results demonstrated that pretreatment with fosaprepitant suppressed the decrease in blood pressure caused by colonic distension. 1 This suggests that A may suppress the drop in blood pressure at the onset of reflex syncope.

[0034] I-2-2. Number of c-FOS immunostained cells in the area postrema, nucleus of the solitary tract, and caudal ventrolateral medulla Representative distributions of c-FOS immunostained positive cells in the area postrema, nucleus tractus solitarius, and caudal ventrolateral medulla are shown in Figure 3 (area postrema and nucleus tractus solitarius) and Figure 4 (caudal ventrolateral medulla). In the nucleus of the solitary tract (NTS), the number of c-Fos immunostained positive cells in the non-CRD group (control) was 907±235 cells / rat, whereas it was significantly increased in the CRD group (CRD) (1,628±530 cells / rat). 1 There was no significant difference in the number of c-Fso immunostaining-positive cells between groups A (1,628 ± 530 cells / rat and 1,504 ± 526 cells / rat, respectively; Fig. 5A ). In the caudal ventrolateral medulla, the number of c-Fos immunostained positive cells in the non-CRD group (control) was 450±140 cells / rat, whereas it was significantly increased in the CRD group (CRD) (1,157±296 cells / rat). Administration of fosaprepitant dramatically reduced the number of c-Fos positive cells in the caudal ventrolateral medulla (CRD+NK). 1 Group A: 784 ± 194 cells / rat; Figure 5B ). The above results are NK 1 This indicates that A may inhibit the projection from the nucleus of the solitary tract to the caudal ventrolateral medulla in the central nervous system transmission of reflex syncope.

[0035] II. NK for syncope cases 1 Examination of the effect of A Case 1. 12 years and 8 months old, toy poodle, neutered female In this case, a Holter ECG test was requested due to the main complaint of syncope, and was performed at Azabu University Animal Hospital. The dog was vomiting due to excitement and squamous cell carcinoma in the mouth, which triggered the dog to faint. The Holter ECG test revealed second-degree atrioventricular block secondary to sinus tachycardia. Since the heart rate was 40 bpm and there was no cardiac arrest for 6 to 8 seconds, which is the time when a dog faints, the dog was diagnosed with mixed reflex syncope, in which the heart rate and blood pressure decrease (January 31, 2023). In this case, the owner reported that the frequency of syncope had decreased since taking maropitant. In other words, this patient experienced seizures on February 2, 6, 16, and 19, 2023, until his death on March 19, 2023. However, he did not experience syncope when maropitant was administered orally at 4.4 mg / kg once a day, and even after oral administration became difficult, maropitant was administered subcutaneously at 2 mg / kg during outpatient visits.

[0036] Case 2. 9 years and 5 months old, Shih Tzu, castrated male In this case, the patient visited Azabu University Animal Hospital with the main complaint of repeated fainting during sleep or walks about once a week, although there were periods when the patient was asymptomatic. The fainting episodes began when the patient was excited from October to November 2022, but then disappeared. The patient fainted again on February 10, 2023, and two weeks later, the patient fainted 4 to 5 times and began screaming. After that, the patient fainted while walking on March 30 and April 10 of the same year, and a Holter electrocardiogram was performed because the patient's weakness lasted longer than usual, and paroxysmal atrioventricular block secondary to sinus tachycardia was confirmed. Pacemaker implantation was proposed, but the patient did not wish to have it performed immediately, so maropitant was prescribed at 2.5 mg / kg SID from April 11. The patient fainted while walking, so maropitant was administered before walks, and fainting was not observed. However, fainting recurred once when maropitant was not administered before walks. The family then opted for pacemaker implantation, which took place on May 10th. However, because the patient had continued taking maropitant as bridging treatment, he did not faint until the day of the surgery, and has since been asymptomatic since the pacemaker was implanted.

[0037] These case studies indicate that maropitant may be effective in treating reflex syncope in dogs through mechanisms other than its antitussive and antiemetic effects, possibly by suppressing excessive parasympathetic nervous activity. [Industrial Applicability]

[0038] The present invention provides a pharmaceutical composition for preventing or treating reflex syncope, and is therefore expected to be useful in the fields of medicine and veterinary medicine.

Claims

1. Neurokinin-1 receptor antagonist (NK 1 A pharmaceutical composition for preventing or treating reflex syncope, comprising A) as an active ingredient.

2. 2. The pharmaceutical composition of claim 1, wherein the reflex syncope is vasovagal syncope, carotid sinus syncope, or situational syncope.

3. The pharmaceutical composition according to claim 2, wherein the vasovagal syncope is emotional syncope, syncope caused by standing / sitting for a long time, or syncope immediately after exercise.

4. The pharmaceutical composition according to claim 2, wherein the situational syncope is cough syncope, swallow syncope, defecation syncope or micturition syncope.

5. The above NK 1 A is Aprepitant, Fosaprepitant, Netupitant, Fosnetupitant, Casopitant, Cizolirtine, Maropitant, Nolpitantium, Vofopitant, Ezlopitant, Figopitant, Vestipitant, Burapitant 5. The pharmaceutical composition according to claim 1, which is selected from the group consisting of befetupitant, rolapitant, serlopitant, tradipitant, immunopitant, elinzanetant, EU-C-001, orbupitant, SDZ-NKT-343, RP-67580, L-741671, FR-113680, FK224, FK888, CP-99994, CP-96345 and CGP-49823.

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