Patent Application
20220313625
The present invention relates to pharmaceutical agents for prophylaxis and/or treatment of a pathological condition with decreased lung compliance, medical solutions for washing pulmonary alveoli having a decrease in lung compliance, and nebulizers.
Acute respiratory failure that follows shock or trauma, etc., was reported in 1967 by Ashbaugh et al. Subsequently, the concept of disease called adult respiratory distress syndrome was proposed. The definitions, onset mechanisms, prognosis, etc., of adult respiratory distress syndrome were discussed in 1992 in the American-European Consensus Conference (AECC) organized jointly by the American Thoracic Society and the European Society of Intensive Care Medicine, in which diagnostic criteria were standardized. The ARDS network was established by U.S. National Institutes of Health (NIH), in which the usefulness of low tidal volume artificial ventilation has been proven. In Japan, the “Guidelines for diagnosis and treatment of ALI/ARDS” was prepared in 2005. Acute lung injury (ALI), which is the same pathological condition but called differently, was classified as a mild form of acute respiratory distress syndrome (ARDS) in the Berlin definition in 2012. In Japan, the “Guidelines for diagnosis and treatment of ARDS” was prepared in 2016 based on the Berlin definition.
ARDS is a syndrome including common symptoms associated with causative disease. A hallmark of ARDS is increased permeability pulmonary edema caused by non-specific inflammation occurring in pulmonary alveoli. In these affected pulmonary alveoli, the accumulation of fluid in the alveolar cavities causes impaired oxygenation and decreased lung compliance, leading to respiratory failure. Endogenous pulmonary surfactant in the pulmonary alveoli reduces a force (surface tension) that tends to minimize the surface area of a liquid, and thereby prevents the collapse of the pulmonary alveoli. Dilution and dysfunction of endogenous pulmonary alveolar surfactant are considered to be a critical factor for a decrease, in surface activity that is the surface tension reduction effect, which leads to a decrease in lung compliance.
ARDS is a type of acute respiratory failure having a sudden onset triggered by diseases caused by direct lung injury (pneumonia, accidental swallowing, fat embolism, inhalation injury due to toxic gas or the like, reperfusion pulmonary edema after lung transplantation, drowning, radiation lung injury, pulmonary contusion, etc.) or diseases caused by indirect lung injury (sepsis, severe trauma, thermal burn, shock, massive blood transfusion, drug intoxication, acute pancreatitis, autoimmune disease, etc.), in persons who generally do not have any lung lesion. Patients with ARDS may have severe hypoxemia, increased pulmonary vascular permeability, pulmonary edema, coughing up of frothy bloody sputum, continuous rhonchi in auscultation, etc., and are likely to be affected by sequelae such as encephalopathy, hyaline membrane formation, and pulmonary fibrosis.
Because of compression by heart, dorsal lung region tends to be easy to collapse in ARDS. It is known that lung collapse causes an increase in shunt ratio, which increase in blood flow for which gas exchange does not take place in the lung. Lung collapse also causes the overdistension, thus ventilator-induced lung injury (VILI)). Although it was reported that low tidal volume artificial ventilation in conjunction with positive end-expiratory pressure (PEEP) artificial ventilation significantly reduces the death rate, high PEEP may cause a decrease in cardiac output and an induction of VILI, and the death rate is still high. As a pathological condition similar to ARDS, infantile respiratory distress syndrome (IRDS), which often occurs in preterm infants born before 32 weeks gestational age, is known. Replacement therapy using a bovine lung extract artificial surfactant is effective in treating IRDS, the major cause of which is lack of endogenous surfactant. However, it was reported that replacement therapy using bovine lung extract artificial surfactant or artificial synthetic surfactant is not effective in improving the life prognosis of ARDS, and it has been suspected that there are any other factors involved, in addition to surfactant (NON-PATENT DOCUMENT 5). Furthermore, as pharmacotherapy, a steroid such as methylprednisolone is used in order to reduce inflammation, which is a symptomatic treatment. There is no effective, prophylactic or therapeutic drug for ARDS. Despite the advances in emergency medicine, the present death rate is still as high as 40-50% (NON-PATENT DOCUMENTS 1-4). Therefore, various studies are being extensively conducted to develop a prophylactic or therapeutic drug that is effective in treating ARDS.
With the above-described problems in mind, the present invention has been made. It is an object of the present invention to provide a pharmaceutical agent for prophylaxis and/or treatment of a pathological condition with decreased lung compliance, a medical solution for washing pulmonary alveoli having a decrease in lung compliance, and a nebulizer.
A pharmaceutical agent according to the present invention is for prophylaxis and/or treatment of a pathological condition with decreased lung compliance, and is characterized by having a polyamine.
A medical solution for washing pulmonary alveoli according to the present invention (note that the medical solution for washing pulmonary alveoli is also referred to as a pulmonary alveolar washing solution) is characterized by having a polyamine.
A nebulizer according to the present invention has an air flow passage that extends from an air introduction opening to a spray opening, and a medical solution reservoir that contains a medical solution and mists the medical solution, wherein air introduced from the air introduction opening is mixed with the medical solution misted in the medical solution reservoir, and the mixed air is discharged from the spray opening, and is characterized in that the medical solution has a polyamine.
According to the present invention, a pathological condition with decreased lung compliance can be effectively prevented and/or treated.
Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. The embodiments are for the purpose of facilitating understanding of the principle of the present invention. The scope of the present invention is not intended to be limited to the embodiments below. Those skilled in the art will make substitutions to the embodiments when necessary without departing the scope of the present invention.
A pharmaceutical agent according to the present invention is for prophylaxis and/or treatment of a pathological condition with decreased lung compliance, and has a polyamine. The present inventors have first found that adding a polyamine(s) to alveoli in which endogenous pulmonary surfactant diluted, in order to adjust to an appropriate concentration of polyamines, allows the lungs to expand and gas exchange to ameliorate. Based on this novel finding, the present invention has been completed.
The pathological condition with decreased lung compliance means, for example, acute respiratory failure in which a chest X-ray photograph taken 12-48 hours after invasion such as trauma or surgery shows pulmonary infiltrative shadow in both of the lungs, and the PaO2/FiO2 ratio is at most 300.
The pathological condition with decreased lung compliance is not particularly limited. Examples of the pathological condition with decreased lung compliance include acute respiratory distress syndrome (ARDS), acute lung injury (a mild form of ARDS that used to be called so), and infant respiratory distress syndrome (IRDS). The pathological condition with decreased lung compliance is preferably ARDS in which the PaO2/FiO2 ratio is at most 300.
Examples of the pathological condition with decreased lung compliance include lung diseases caused by dysfunctional endogenous pulmonary alveolar surfactant, multiple organ dysfunction syndrome (MODS), and cardiogenic pulmonary edema.
A medical solution for washing pulmonary alveoli according to this embodiment is characterized by having a polyamine.
The polyamine collectively means aliphatic hydrocarbons having two or more primary amino groups. The polyamine is not particularly limited in the present invention. Examples of the polyamine include spermine (Spm), spermidine (Spd), putrescine (Put), and a mixture thereof.
The polyamine can, for example, be acetylputrescine, N1-acetylspermidine, N8-acetylspermidine, N1-acetylspermine, or a mixture thereof.
The polyamine can also, for example, be 1,3-diaminopropane, diaminohexane, cadaverine, agmatine, caldine, homospermidine, aminopropylcadaverine, thermine, thermospermine, canavalmine, aminopentylnorspermidine, N,N-bis(aminopropyl)cadaverine, homospermine, caldopentamine, homocaldopentamine, caldohexamine, homocaldohexamine, or a mixture thereof.
As used herein, the term “prevention” or “prophylaxis” refers to preventing or delaying the onset of a disease or disorder, and includes not only prevention or prophylaxis of occurrence of a disease or disorder, but also prevention or prophylaxis of recurrence of a disease or disorder. As used herein, the term “treatment” or “therapy” refers to eliminating or ameliorating symptoms, and inhibiting the development or progression of symptoms.
The pharmaceutical agent according to this embodiment can be formulated and administered using known techniques. For example, the pharmaceutical agent according to this embodiment can be administered orally or parenterally to humans or mammals in its original liquid form or in an appropriate dosage form. The liquid agent herein includes a product obtained by dissolving a tablet, powder, lyophilized agent, etc., in a solvent (water or physiological saline). In the case of parenteral administration, administration is preferably carried out by inhalation using a nebulizer, artificial ventilator, or inhaler, or by bronchoscope.
The pharmaceutical agent may contain an antiseptic for inhibiting the growth of microorganisms or a buffering agent for maintaining pH in an acceptable range. Examples of the antiseptic include sodium azide, octadecyl dimethyl benzyl ammonium chloride, hexamethonium chloride, benzalkonium chloride, benzethonium chloride, phenol, butyl or benzyl alcohol, alkyl parabens such as methyl or propyl paraben, catechol, resorcinol, cyclohexanol, 3-pentanol, and m-cresol. Examples of the buffering agent include phosphoric acid, citric acid, and other organic acids.
The pharmaceutical agent may also contain, for example, an excipient, stabilizer, chelating agent, such as EDTA, salt, or antimicrobial agent. In addition, the pharmaceutical agent can contain antioxidants, such as ascorbic acid and methionine, proteins, such as polypeptides, serum albumin, gelatin, or non-specific immunoglobulins, hydrophilic polymers, such as polyvinyl pyrrolidone, amino acids, such as glycine, glutamine, asparagine, histidine, arginine, and lysine, monosaccharides, disaccharides, and other carbohydrates, such as glucose, mannose, and dextrin, and sugars, such as sucrose, mannitol, trehalose, and sorbitol.
In biological tissue, about 1 mM of polyamines intracellularly synthesized or intestinally absorbed are mainly present in cells. The concentration of extracellular polyamines is about 1/1000- 1/100 of that of intracellular polyamines. It is inferred that polyamines at secretory sites, such as synapses, exist in relatively high concentrations locally. Living organisms have a preserved feedback mechanism for regulating the concentration of intracellular polyamines from becoming too high. Extra polyamines may reduce production of intracellular polyamines. It is, therefore, considered that when a polyamine is administered into pulmonary alveoli for the purpose of prophylaxis and/or treatment, it is preferable that the polyamine concentration at the surface of pulmonary alveoli should not excessively deviate from the intracellular polyamine concentration.
Examples 3 and 5 showed that the presence of 1 mM of Spm at the surface of pulmonary alveoli allowed lung compliance and oxygenation to improved. Therefore, the effective Spm concentration performed at the surface of pulmonary alveoli is considered to be, not limited to, about 1-2 mM.
In administering a polyamine-containing medical solution to a lung affected by ARDS, the efficiency of exchange between exudate retained in pulmonary alveoli and the polyamine-containing medical solution for washing affects the polyamine concentration performed at the surface of pulmonary alveoli. Exchange efficiency is affected by dead volume such as tubes and trachea that do not contribute to the exchange, residual exudate volume, and medical solution volume for washing. Assuming that the polyamine-containing medical solution and the exudate are thoroughly mixed together by a pulmonary alveolar washing operation, a rough calculation indicates that if the exchange efficiency achieved by performing washing once is about 15%, the polyamine concentration produced at the surface of pulmonary alveoli become about 2 mM after washing with a 4-mM polyamine-containing medical solution 5 times consecutively. Thus, it should be considered and determined that the concentration of polyamine-containing medical solution administered will be diluted by exudate. Example 7 shows an effect obtained when washing with a medical solution containing 5 mM of Spm was carried out 5 times consecutively on ARDS rats produced by pulmonary alveolar washing with physiological saline. Although not particularly limited, in the case where the polyamine contained in the medical solution is Spm, the selected medical solution concentration is about 1-50 mM, 1-10 mM, or 1-5 mM for intralesional use, or about 1-10 mM, preferably about 1-5 mM, for use in a wide region including a lesion.
The pharmaceutical agent according to the present invention can be incorporated into liposomes for drug delivery. The liposome contains, for example, a phospholipid, such as a phosphatidylserine (PS) or phosphatidylcholine (PC), as a membrane component. The diameter of the liposome can be suitably adjusted, taking into account the success rate of delivery to target tissue, stability, etc. The liposome is, for example, a monolayer liposome having a diameter of 150-350 nm.
The pharmaceutical agent according to the present invention has a polyamine, and can further contain a phospholipid component or a phospholipid. The major component of endogenous pulmonary surfactant is phospholipids. A commercially available bovine lung extract artificial surfactant contains 84% of phospholipids.
The phospholipid component and phospholipid are not particularly limited. Examples of the phospholipid component and phospholipid include dipalmitoyl-phosphatidylcholine (DPPC), phosphatidylcholines (PC), phosphatidylglycerols (PG), distearoylphosphatidylcholine (DSPC), distearoylphosphatidylglycerol (DSPG), dimyristoyl-phosphatidylethanolamine (DMPE), dipalmitoylphosphatidylethanolamine (DPPE), dioleylphosphatidylethanolamine (DOPE), distearoylphosphatidylethanolamine (DSPE), diarachidoylphosphatidylethanolamine (DAPE) or dilinoleylphosphatidylethanolamine (DLPE), dilauroyl-phosphatidylcholine (DLPC), dimyristoyl-phosphatidylcholine (DMPC), diarachidoyl-phosphatidylcholine (DAPC), dioleyl-phosphatidylcholine (DOPC), dimyristoylphosphatidylserine (DMPS), diarachidoylphosphatidylserine (DAPS), dipalmitoylphosphatidylserine (DPPS), distearoylphosphatidylserine (DSPS), dioleylphosphatidylserine (DOPS), dipalmitoylphosphatidic acid (DPPA), dimyristoylphosphatidic acid (DMPA), distearoylphosphatidic acid (DSPA), diarachidoylphosphatidic acid (DAPA), dimyristoylphosphatidylglycerol (DMPG), dipalmitoylphosphatidylglycerol (DPPG), dioleyl-phosphatidylglycerol (DOPG), dilauroylphosphatidylinositol (DLPI), diarachidoylphosphatidylinositol (DAPI), dimyristoylphosphatidylinositol (DMPI), dipalmitoylphosphatidylinositol (DPPI), distearoylphosphatidylinositol (DSPI), dioleylphosphatidylinositol (DOPI), and a mixture thereof.
It has been reported that the pulmonary surfactant replacement therapy is not effective in treating, for example, ARDS. However, it is effective to use the pulmonary surfactant replacement therapy in conjunction with the pharmaceutical agent having a polyamine according to the present invention for treatment of ARDS.
As shown in
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Administration of a medical solution using a bronchoscope is locally available to a lesional portion, each lobe, or each lung, which is suitable for treatment of pathological conditions with a severe symptom. Therefore, in the case of administration using a bronchoscope, a high-concentration medical solution can be used. Although not particularly limited, the polyamine concentration can, for example, be 2-100 mM. If it is difficult to administer using a bronchoscope in severe cases, it is possible to do using a nebulizer as described above.
In Example 1, the effect of improving lung compliance by polyamines administered to pulmonary alveoli was studied based on the a polyamine composition ratio (Put:Spd:Spm=0.1:3:2) in pulmonary alveoli of a euthanized mouse.
A tracheal cannula was inserted into a rat under general anesthesia. When the respiratory and circulatory dynamics of the rat were stable under artificial ventilation, an injection/suction operation using 20 ml/kg of a pulmonary alveolar washing solution (physiological saline) through the tracheal cannula was conducted 3 times consecutively within 2 minutes. After the washing solution remaining in the trachea was suctioned out, artificial ventilation was immediately resumed. Thus, an ARDS model whose pulmonary alveoli were washed with physiological saline was produced. The pulmonary alveolar washing operation means production of a respiratory distress syndrome (ARDS) model having decreased lung compliance.
A tracheal cannula was inserted into a rat under general anesthesia. When the respiratory and circulatory dynamics of the rat were stable under artificial ventilation, 20 ml/kg of a pulmonary alveolar washing solution (physiological saline containing 0.51 mM of polyamines (composition ratio is Put:Spd:Spm=0.1:3:2) was injected/suctioned consecutively 3 times within 2 minutes through the tracheal cannula. After the washing solution remaining in the trachea was suctioned out, artificial ventilation was immediately resumed. Thus, an ARDS model whose pulmonary alveoli were washed with the polyamines was produced. The pulmonary alveolar washing with a polyamine-containing physiological saline means production of an ARDS model and administration of polyamines to pulmonary alveoli, which are simultaneously carried out.
The above ventilation was conducted by inverse ratio ventilation without using PEEP. The ventilation was conducted using ambient air (inhaled oxygen concentration FiO2: 0.21) without oxygen administration. The intra-airway pressure and the partial pressure of oxygen in the arterial blood (PaO2) were measured over time. Influence of the polyamines was analyzed, where dynamic lung compliance (=a tidal volume/a change in intra-airway pressure) (expression 1) was used as a measure of the distensibility of the lung, and PaO2/FiO2 (P/F ratio)<300 was used as a criterion for gas exchange dysfunction.
The result is shown in
In Example 2, the effect of improving lung compliance by a polyamine (0.5 mM of Spm) administered to pulmonary alveoli was studied.
A tracheal cannula was inserted into a rat under general anesthesia. When the respiratory and circulatory dynamics of the rat were stable under artificial ventilation, 20 ml/kg of a pulmonary alveolar washing solution (physiological saline) was injected/suctioned consecutively 5 times within 2 minutes through the tracheal cannula. After the washing solution remaining in the trachea was suctioned out, artificial ventilation was immediately resumed. Thus, an ARDS model whose pulmonary alveoli were washed with physiological saline was produced.
A tracheal cannula was inserted into a rat under general anesthesia. When the respiratory and circulatory dynamics of the rat were stable under artificial ventilation, 20 ml/kg of a pulmonary alveolar washing solution (physiological saline containing 0.5 mM of Spm) was injected/suctioned consecutively 5 times within 2 minutes through the tracheal cannula. After the washing solution remaining in the trachea was suctioned out, artificial ventilation was immediately resumed. Thus, an ARDS model whose pulmonary alveoli were washed with 0.5 mM of Spm was produced.
The above ventilation was conducted by inverse ratio ventilation without using PEEP. The ventilation was conducted using ambient air (inhaled oxygen concentration FiO2: 0.21) without oxygen administration. The intra-airway pressure and the partial pressure of oxygen in the arterial blood (PaO2) were measured over time. Influence of the polyamine was analyzed, where dynamic lung compliance was used as a measure of the distensibility of the lung, and the P/F ratio <300 was used as a criterion for gas exchange dysfunction.
Influence of the polyamine was analyzed in a manner similar to that of Example 1.
The result is shown in
In Example 3, the effect of improving lung compliance, depending on the concentration of Spm administered to pulmonary alveoli, was compared and studied.
A tracheal cannula was inserted into a rat under general anesthesia. When the respiratory and circulatory dynamics of the rat were stable under artificial ventilation, 20 ml/kg of a pulmonary alveolar washing solution (physiological saline) was injected/suctioned consecutively 5 times within 2 minutes through the tracheal cannula. After the washing solution remaining in the trachea was suctioned out, artificial ventilation was immediately resumed. Thus, an ARDS model whose pulmonary alveoli were washed with physiological saline was produced.
A tracheal cannula was inserted into a rat under general anesthesia. When the respiratory and circulatory dynamics of the rat were stable under artificial ventilation, 20 ml/kg of a pulmonary alveolar washing solution (physiological saline containing 1 mM of Spm) was injected/suctioned consecutively 5 times within 2 minutes through the tracheal cannula. After the washing solution remaining in the trachea was suctioned out, artificial ventilation was immediately resumed. Thus, an ARDS model whose pulmonary alveoli were washed with 1 mM of Spm was produced.
A tracheal cannula was inserted into a rat under general anesthesia. When the respiratory and circulatory dynamics of the rat were stable under artificial ventilation, 20 ml/kg of a pulmonary alveolar washing solution (physiological saline containing 0.5 mM of Spm) was injected/suctioned consecutively 5 times within 2 minutes through the tracheal cannula. After the washing solution remaining in the trachea was suctioned out, artificial ventilation was immediately resumed. Thus, an ARDS model whose pulmonary alveoli were washed with 0.5 mM of Spm was produced.
The above ventilation was conducted by inverse ratio ventilation without using PEEP. The ventilation was conducted using ambient air (inhaled oxygen concentration FiO2: 0.21) without oxygen administration. The intra-airway pressure and the partial pressure of oxygen in the arterial blood (PaO2) were measured over time. Influence of the polyamine was analyzed, where dynamic lung compliance was used as a measure of the distensibility of the lung, and the P/F ratio <300 was used as a criterion for gas exchange dysfunction.
Influence of the polyamine was analyzed in a manner similar to that of Example 1.
The result is shown in
In Example 4, an additional experiment was conducted to demonstrate whether diluted surfactant does not have the effect of improving lung compliance, and that the presence of 1 mM of Spm does.
A tracheal cannula was inserted into a rat under general anesthesia. When the respiratory and circulatory dynamics of the rat were stable under artificial ventilation, 20 ml/kg of a pulmonary alveolar washing solution (0.3 mg/ml of a bovine lung extract artificial surfactant; the bovine lung extract artificial surfactant was formulated by dissolving Surfacten (trade name), manufactured by Mitsubishi Tanabe Pharma Corporation, in physiological saline to a concentration of 0.3 mg/ml, which is 1/100 of the concentration that is normally for administration to a preterm infant) was injected/suctioned consecutively 5 times within 2 minutes through the tracheal cannula. After the washing solution remaining in the trachea was suctioned out, artificial ventilation was immediately resumed. Thus, an ARDS model whose pulmonary alveoli were washed with the diluted bovine lung extract artificial surfactant was produced. Note that it was confirmed that no polyamines are detected in the bovine lung extract artificial surfactant.
A tracheal cannula was inserted into a rat under general anesthesia. When the respiratory and circulatory dynamics of the rat were stable under artificial ventilation, 20 ml/kg of a pulmonary alveolar washing solution (0.3 mg/ml of a bovine lung extract artificial surfactant containing 1 mM of Spm; the bovine lung extract artificial surfactant was Surfacten (trade name), manufactured by Mitsubishi Tanabe Pharma Corporation) was injected/suctioned consecutively 5 times within 2 minutes through the tracheal cannula. After the washing solution remaining in the trachea was suctioned out, artificial ventilation was immediately resumed. Thus, an ARDS model whose pulmonary alveoli were washed with the diluted bovine lung extract artificial surfactant containing 1 mM of Spm was produced.
The above ventilation was conducted by inverse ratio ventilation without using PEEP. The ventilation was conducted using ambient air (inhaled oxygen concentration FiO2: 0.21) without oxygen administration. The intra-airway pressure and the partial pressure of oxygen in the arterial blood (PaO2) were measured over time. Influence of the polyamine was analyzed, where dynamic lung compliance was used as a measure of the distensibility of the lung, and the P/F ratio <300 was used as a criterion for gas exchange dysfunction.
Influence of the polyamine was analyzed in a manner similar to that of Example 1.
The result is shown in
In Example 5, the effect of improving gas exchange by administering Spm to pulmonary alveoli was studied.
An ARDS model whose pulmonary alveoli were washed with physiological saline, an ARDS model whose pulmonary alveoli were washed with 1 mM of Spm, and an ARDS model whose pulmonary alveoli were washed with 0.5 mM of Spm, were produced in a manner similar to that of Example 3.
An ARDS model whose pulmonary alveoli were washed with a 0.3 mg/ml bovine lung surfactant, and an ARDS model whose pulmonary alveoli were washed with a 0.3 mg/ml bovine lung surfactant containing 1 mM of Spm, were produced in a manner similar to that of Example 4.
Ventilation was conducted by inverse ratio ventilation without using PEEP. The ventilation was conducted using ambient air (inhaled oxygen concentration FiO2: 0.21) without oxygen administration. The intra-airway pressure and the partial pressure of oxygen in the arterial blood (PaO2) were measured over time. Influence of the polyamine was analyzed, where dynamic lung compliance was used as a measure of the distensibility of the lung, and the P/F ratio <300 was used as a criterion for gas exchange dysfunction.
Arterial blood sampling was conducted before pulmonary alveolar washing, 20 minutes after the washing, and 60 minutes after the washing, and the partial pressure of oxygen in the arterial blood (PaO2) was measured using a blood gas analyzer. Influence of Spm administered to pulmonary alveoli on the rate of occurrence of gas exchange dysfunction was analyzed, where the P/F ratio <300 was used as a criterion for gas exchange dysfunction. A decrease in percutaneous arterial oxygen saturation (SpO2), which has a correlation with PaO2, was observed in an oxygen dissociation curve. Cases (death) that death occurred before the measurement times, i.e., arterial blood sampling was not conducted, were counted as the case of occurrence of gas exchange dysfunction.
The result is shown in
The result is shown in
Thus, it was demonstrated that administration of Spm to pulmonary alveoli has the effect of improving gas exchange.
In Example 6, influence of pulmonary alveolar washing with Spm-containing physiological saline on a lung field image was studied. Plain X-ray imaging and X-ray CT imaging were performed, with an air pressure (0 and 20 cm H2O) exerted through a tracheal cannula, on rats that were euthanized after pulmonary alveolar washing or rats that were subjected to pulmonary alveolar washing immediately after euthanization.
A rat a was a control that was not subjected to pulmonary alveolar washing. Specifically, a tracheal cannula was inserted into a rat under general anesthesia, and the rat was euthanized without pulmonary alveolar washing.
A rat b was subjected to pulmonary alveolar washing with physiological saline containing 1 mM of Spm. Specifically, a tracheal cannula was inserted into a rat under general anesthesia, and after the rat was euthanized, 20 ml/kg of a pulmonary alveolar washing solution (physiological saline containing 1 mM of Spm) was injected/suctioned consecutively 5 times within 2 minutes through the tracheal cannula, and the washing solution remaining in the trachea was suctioned out.
A rat c was subjected to pulmonary alveolar washing with physiological saline. Specifically, a tracheal cannula was inserted into a rat under general anesthesia. When the respiratory and circulatory dynamics of the rat were stable under artificial ventilation, 20 ml/kg of a pulmonary alveolar washing solution (physiological saline) was injected/suctioned consecutively 5 times within 2 minutes through the tracheal cannula. After the washing solution remaining in the trachea was suctioned out, artificial ventilation was immediately resumed, and 30 minutes after that, the rat was euthanized.
A rat d was subjected to pulmonary alveolar washing with physiological saline, and then pulmonary alveolar washing with physiological saline containing 5 mM of Spm. Specifically, a tracheal cannula was inserted into a rat under general anesthesia, and after the rat was euthanized, 20 ml/kg of a pulmonary alveolar washing solution (physiological saline) was injected/suctioned consecutively 5 times within 2 minutes through the tracheal cannula, and the washing solution remaining in the trachea was suctioned out. Following this, an injection/suction operation using 20 ml/kg of a pulmonary alveolar washing solution (physiological saline containing 5 mM of Spm) through the tracheal cannula was conducted 5 times consecutively within 2 minutes, and the washing solution remaining in the trachea was suctioned out.
The imaging device was an experimental animal X-ray CT device, Latheta LCT-200. The imaging conditions were as follows: the voxel size was 120 pin; the angle of rotation was 360°; the rotational speed was normal; and the X-ray tube voltage was low.
The result was shown in
In Example 7, influence of transairway administration of 5 mM of Spm to an ARDS model animal on lung compliance was studied.
It was demonstrated in Example 6 that the transairway administration of 5 mM of Spm by pulmonary alveolar washing with physiological saline containing 5 mM of Spm made the air in the lung field in ARDS model animal increase in a CT image captured in the presence of an applied pressure of 20 cm H2O (
A tracheal cannula was inserted into a rat under general anesthesia, and then euthanized. Immediately after that, artificial ventilation was conducted for 30 seconds, and lung compliance before washing that is calculated based on intra-airway pressure was set as 1.0 (“before washing” on the left slide of
The result is shown in
It was demonstrated in Examples 6 and 7 that the technique of administration by pulmonary alveolar washing is effective as a form of administration of a polyamine to a lung affected by ARDS. If a bronchoscope is used, bronchoalveolar lavage (BAL) allows localized administration to a lesion. BAL also allows removal of inflammation cytokines and exudates before polyamine administration. Example 7 shows the possibility that the lung compliance of a patient decreases on BAL test that is conducted by alveolar washing with physiological saline. Examples 6 and 7 indicate that at the last bronchial washing operation, BAL using a physiological saline containing polyamine can prevent pulmonary collapse, one of the complications.
In Example 8, influence of a polyamine on surface tension in a diluted surfactant environment in which the surface tension reduction effect is weakened, was studied.
It is considered that in ARDS, the main cause for the collapse of pulmonary alveoli and decreased lung compliance is that the “surface tension reduction effect” exhibited by endogenous pulmonary surfactant is weakened by exudate accumulated in pulmonary alveolar cavities. In Examples 6 and 7, the transairway administration of 5 mM of Spm to a lung affected by ARDS increased the volume of air in the lung and improved compliance. Therefore, it was inferred that 5 mM of Spm has the effect of recovering the “surface tension reduction effect” that was weakened due to dilution of endogenous surfactant. This inference was studied in Example 8 in an in vitro experimental system using a bovine lung extract artificial surfactant. In other words, it was studied whether a polyamine reduces the “increased surface tension” due to dilution of a bovine lung surfactant.
Surface tension was measured by the Young-Laplace method (curve fitting) using a contact angle meter (B100, manufactured by Asumi Giken, Limited), on a droplet formed at the tip of a 20-gauge straight needle.
Tensiometer: contact angle meter (B100, manufactured by Asumi Giken, Limited)
Surface tension measurement method: Young-Laplace method (curve fitting)
Hanging droplet production method: a maximum size of droplet not to drop was produced at the tip of a 20-gauge straight needle (an autodispenser was used)
Imaging of hanging droplet: imaging was performed using a CCD camera
Bovine lung surfactant: a commercially available bovine lung extract artificial surfactant (Surfacten (trade name), manufactured by Mitsubishi Tanabe Pharma Corporation) was adjusted to a concentration of 30 mg/ml using physiological saline according to the package insert. The concentration of 30 mg/ml is one for treatment of a preterm infant who has pulmonary alveoli collapsed due to lack of pulmonary surfactant. In the drawings, the formulated surfactant solution is indicated by “30 mg/ml surf.”
10-fold diluted bovine lung surfactant: a commercially available bovine lung extract artificial surfactant (Surfacten (trade name), manufactured by Mitsubishi Tanabe Pharma Corporation) was adjusted to a concentration of 3 mg/ml using physiological saline. In the drawings, the formulated surfactant solution is indicated by “3 mg/ml surf.”
100-fold diluted bovine lung surfactant: a commercially available bovine lung extract artificial surfactant (Surfacten (trade name), manufactured by Mitsubishi Tanabe Pharma Corporation) was adjusted to a concentration of 0.3 mg/ml using physiological saline. Pulmonary surfactant was diluted with physiological saline, i.e., the resultant solution mimics the state of surfactant in a lung affected by ARDS. In the drawings, the formulated surfactant solution is indicated by “100-fold diluted bovine lung surfactant,” “0.3-mg/ml bovine lung surfactant,” “0.3 mg/ml surf,” or “ 1/100 Surf.”
1000-fold diluted bovine lung surfactant: a commercially available bovine lung extract artificial surfactant (Surfacten (trade name), manufactured by Mitsubishi Tanabe Pharma Corporation) was adjusted to a concentration of 0.03 mg/ml using physiological saline. In the drawings, the formulated surfactant solution is indicated by “0.03 mg/ml surf.”
It was verified that no polyamines were detected in the bovine lung surfactant.
Polyamine-containing 100-fold diluted bovine lung surfactant:
Spermine, which is a representative example of a major polyamine present in the higher animals (claim 3), N1-acetylspermidine, which is a representative example of an acetylated polyamine (claim 4), or diaminohexane, which is a representative example of a polyamine which is not present in the higher animals (claim 5), was added to a diluted pulmonary Surfacten solution, and the presence or absence of the surface tension reduction effect was analyzed. The solution was formulated using a commercially available polyamine chloride.
A spermine-containing 100-fold diluted bovine lung surfactant is indicated, in the drawings and specification, by “Spm-containing 0.3 mg/ml bovine lung surfactant,” “Spm-containing 1/100 surf,” or “Spm-containing 0.3 mg/ml surf.”
A spermidine-containing 100-fold diluted bovine lung surfactant is indicated, in the drawings and specification, by “Spd-containing 0.3 mg/ml bovine lung surfactant,” Spd-containing 1/100 surf,” or “Spd-containing 0.3 mg/ml surf.”
A putrescine-containing 100-fold diluted bovine lung surfactant is indicated, in the drawings and specification, by “Put-containing 0.3 mg/ml bovine lung surfactant,” “Put-containing 1/100 surf,” or “Put-containing 0.3 mg/ml surf.”
An N1-acetylspermidine-containing 100-fold diluted bovine lung surfactant is indicated, in the drawings and specification, by “N1-AcSpd-containing 0.3 mg/ml bovine lung surfactant,” “AcSpd-containing 1/100 surf,” or “AcSpd-containing 0.3 mg/ml surf.”
A 1-mM diaminohexane-containing 100-fold diluted bovine lung surfactant is indicated, in the drawings and specification, by “diaminohexane-containing 0.3 mg/ml bovine lung surfactant,” “diaminohexane-containing 1/100 surf,” or “diaminohexane-containing 0.3 mg/ml surf.”
The results are shown in
In
Spm alone does not have such a surface tension reduction effect and was also demonstrated in the experiment (e.g., in the case of 0.5 mM of Spm, 64 mN/m, 0-10000 msec). It is assumed that 5 mM of Spm administered to a lung in ARDS model was mixed with physiological saline remaining in pulmonary alveolar cavities, so that the concentration of Spm became several millimoles lower than 5 mM, and that Spm exhibited the surface tension reduction defected by cooperated with the twice diluted endogenous pulmonary surfactant remaining in the lung (
Like Spm, Spd or Put alone does not have the surface tension reduction effect. It is considered that the surface tension reduction effect found in the above experiments (arrow with a downward arrowhead in the left graph of
One millimole of N1-AcSpd or 1 mM of diaminohexane alone does not have the surface tension reduction effect (63 mN/m, 62 mN/m, 0-10000 msec). The surface tension reduction effect found in this experiment (arrow with a downward arrowhead in
Thus, it was demonstrated that Spm, which is a representative polyamine that is endogenous to the pulmonary alveolar cavities, has the effect of recovering surface activity that was lost due to dilution of pulmonary surfactant (
Spd and Put, which are endogenous to the pulmonary alveolar cavities, also have the effect of recovering surface activity that was lost due to dilution of pulmonary surfactant (
In addition to major polyamines present in the higher animals (claim 3), acetylated polyamines (claim 4) and polyamines that are not present in the higher animals (claim 5), have the effect of recovering surface activity that was lost due to dilution of pulmonary surfactant (
In addition, no polyamine alone has the surface tension reduction effect. Therefore, it is inferred that polyamines and surfactant that are endogenous to the pulmonary alveolar cavities cooperate together to contribute to a reduction in surface tension. It has been reported that replacement therapy using a bovine lung extract artificial surfactant or totally-synthesized artificial surfactant is not effective to patients with ARDS. In the above examples, administration of several millimoles of a polyamine to pulmonary alveolar cavities alone led to an improvement in lung compliance, prevention of the collapse of the lungs, and amelioration of gas exchange dysfunction. Therefore, the above results show that the presence of several millimoles of a polyamine in pulmonary alveolar cavities is crucial irrespective of somewhat dilution of surfactant. It is known that the polyamine concentration is high in individuals during developmental processes. While the concentration of polyamines endogenous to the pulmonary alveolar cavities is possibly sufficient in IRDS, the polyamine concentration in the pulmonary alveolar cavities is possibly low due to exudates in ARDS, which it is considered makes the artificial pulmonary surfactant replacement therapy effective and ineffective, respectively.
The result of the in vitro experiment (Example 8) demonstrated that polyamines cooperate with pulmonary surfactant to exhibit the surface tension reduction effect. When active pulmonary surfactant is diluted, transairway administration of, for example, Spm alone at an appropriate concentration leads to an improvement in lung compliance and oxygenation (
In Example 9, polyamines were analyzed in terms of the surface tension reduction effect (in vitro), based on the polyamine composition ratio in pulmonary alveoli of a rat under general anesthesia, and the lung compliance improvement effect of optimized administration of polyamines to pulmonary alveoli was studied.
A tracheal cannula was inserted into a rat under general anesthesia. When the respiratory and circulatory dynamics of the rat were stable under artificial ventilation, 20 ml/kg of a pulmonary alveolar washing solution (physiological saline) was injected/suctioned consecutively 5 times within 2 minutes through the tracheal cannula. The polyamine composition in the collected washed-fluid was analyzed (left in
A tracheal cannula was inserted into a rat under general anesthesia. When the respiratory and circulatory dynamics of the rat were stable under artificial ventilation, 20 ml/kg of a pulmonary alveolar washing solution (100-fold diluted bovine lung extract surfactant) was injected/suctioned consecutively 5 times within 2 minutes through the tracheal cannula. The polyamine composition in the collected washed-fluid was analyzed (right in
For the polyamine compositions mix1 and mix2, surface tension was analyzed using the method described in Example 8 in order to obtain an optimum concentration having a high surface tension reduction effect.
The following polyamine mix-containing 100-fold diluted bovine lung extract artificial surfactants were used.
A polyamine mix 1-containing 100-fold diluted bovine lung extract artificial surfactant is indicated, in the drawings and specification, by “polyamine mix 1 (Put:Spd:Spm=1:2.5:1.5)-containing 0.3-mg/ml pulmonary surfactant” or “polyamine mix 1-containing 0.3 mg/ml surf.”
A polyamine mix 2-containing 100-fold diluted bovine lung extract artificial surfactant is indicated, in the drawings and specification, by “polyamine mix 2 (Put:Spd:Spm=0.8:2.1:2.1)-containing 0.3-mg/ml pulmonary surfactant” or “polyamine mix 2-containing 0.3 mg/ml surf.”
An in vivo experiment below was conducted in order to determine whether or not the polyamine composition mix2, which has an optimum surface tension reduction effect obtained in the above in vitro experiment, has the lung compliance improvement effect.
A tracheal cannula was inserted into a rat under general anesthesia. When the respiratory and circulatory dynamics of the rat were stable under artificial ventilation, 20 ml/kg of a pulmonary alveolar washing solution (physiological saline containing an optimum concentration of the polyamine mix 2) was injected/suctioned consecutively 5 times within 2 minutes through the tracheal cannula. After the washing solution remaining in the trachea was suctioned out, artificial ventilation was immediately resumed. Thus, an ARDS model whose pulmonary alveoli were washed with the polyamine mix 2 having the optimum concentration was produced.
The above ventilation was conducted by inverse ratio ventilation without using PEEP. The ventilation was conducted using ambient air (inhaled oxygen concentration FiO2: 0.21) without oxygen administration. The intra-airway pressure was measured over time. Influence of the polyamines was analyzed, where dynamic lung compliance was used as a measure of the distensibility of the lung.
The results are shown in
The embodiments are useful in treatment of acute respiratory distress syndrome (ARDS), lung diseases caused by dysfunctional endogenous pulmonary alveolar surfactant, multiple organ dysfunction syndrome (MODS), and cardiogenic pulmonary edema. The embodiments are also useful in prophylaxis of a decrease in lung compliance after a bronchoalveolar lavage (BAL) test.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019-097756 | May 2019 | JP | national |
| 2020-006158 | Jan 2020 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2020/020116 | 5/21/2020 | WO |
