JP5770997B2 - Method for measuring metabolic function of CYP3A4 - Google Patents

Description

  The present invention relates to a method for measuring and evaluating the metabolic function of cytochrome P450 3A4 isozyme (CYP3A4).

  Treatment-specific diagnosis (also known as “thelanostic”) provides a useful test for diagnosing disease, selecting the right treatment plan, and monitoring patient response. That is, theranostics are useful for predicting and assessing drug response in individual patients, and are useful for selecting patients that are particularly likely to benefit from their medication. Therefore, according to the theranostic, it becomes possible to objectively provide an effective treatment policy for individual patients at an early stage, and it is useful for optimal treatment while minimizing treatment delay.

  Many enzymes such as cytochrome P450, glucuronic acid transfer toxin, sulfotransferase, and acetyltransferase are involved in the metabolism of pharmaceuticals. Among these, P450 is the most important drug because its metabolic process often becomes the rate-limiting factor when the drug disappears from the living body, and there are a wide variety of drugs that undergo metabolism, and the number is extremely high. It can be said to be a metabolic enzyme. One of the reasons that P450 may be involved in the metabolism of many kinds of drugs is that there are many isozymes (CYPs). Currently, there are about 20 isozymes that are only involved in human drug metabolism. Are known. These are classified into four families, CYP1 to CYP4, based on gene homology, and each family is further subclassified as CYP2A, CYP2B, CYP2C, etc., and one subfamily consists of 1 to 5 isozymes. It is composed of Among these, CYP3A4 is the isozyme most frequently involved in the metabolism of pharmaceuticals, followed by CYP2D6, CYP2C19, CYP2C9, CYP1A2, and the like.

Therefore, from the perspective of the theranostic, evaluating the metabolic activity of major cytochrome P450 isozymes (CYPs), and simply evaluating and diagnosing them, avoids potential drug-related toxicities in those with metabolic deficiencies and is effective. It is highly useful for raising
Among them, CYP3A4 is the most abundant CYP in human liver, and is said to be involved in the metabolism of about 50% of drugs used in human therapy, and there are individual differences in enzyme activity of CYP3A4. Since it is known, it is extremely useful to evaluate the function of the enzyme. On the other hand, although 28 or more single nucleotide polymorphisms have been identified in the gene encoding CYP3A4, these are known not to be reflected in individual differences in vivo, and the function of CYP3A4 is evaluated by genetic diagnosis. This is impossible, and a method that can easily evaluate and test the metabolic activity of CYP3A4 is highly desired.

Currently, the metabolic activity of CYP3A4 is measured non-invasively by the erythromycin breath test (ERMBT). That is, there is a method for determining in vivo CYP3A4 activity by administering ¹⁴ C-erythromycin by intravenous infusion and measuring isotope-labeled CO ₂ contained in exhaled breath (see Non-Patent Document 1). Although known, this method has a demerit in terms of operability and safety in terms of using an isotope. In addition, it is not easy to synthesize a compound obtained by converting ¹⁴ C of ¹⁴ C-erythromycin into ¹³ C (see Non-Patent Document 2). Required and impractical.

Fundamental & Clinical Pharmacology (2003), 17 (3), 349-353 Ther Drug Monit. 2007 Apr; 29 (2): 225-30.

  The present invention relates to providing a method for measuring and evaluating the metabolic function of CYP3A4 simply and safely.

Because the proton pump inhibitor pantoprazole is demethylated by CYP2C19 to produce 4-hydroxypantoprazole and carbon dioxide, the applicant administers ¹³ C-pantoprazole to the patient and during exhalation A patent application was filed for a method of measuring the metabolic function of CYP2C19 by measuring the amount of ¹³ CO ₂ discharged (WO 2008/028116 pamphlet).

On the other hand, ¹³ C-pantoprazole is also oxidized by CYP3A4 to produce a sulfone body. However, when erythromycin is competitively present in the metabolic system, the present inventors excrete it into the breath by the action of CYP2C19. It was found that the amount of ¹³ CO ₂ increased depending on the dose of erythromycin. That is, the metabolic functions of CYP3A4 and CYP2C19 are linked, and a compound having the ability to produce isotope-labeled CO ₂ by CYP2C19 after being administered to a mammal, such as ¹³ C-pantoprazole, becomes a substrate for both CYP3A4 and CYP2C19. It was found that the presence or absence of the metabolic function of CYP3A4 can be measured by measuring the degree of increase in ¹³ CO ₂ excreted into the exhaled breath.

That is, the present invention relates to the following 1) to 10).
1) A CYP3A4 metabolic function measuring agent comprising a ¹³ C-labeled substrate compound which becomes a substrate for CYP3A4 and CYP2C19 and has the ability to generate ¹³ CO ₂ by CYP2C19 after administration to a test mammal.
2) The CYP3A4 metabolic function assay agent according to 1) above, wherein the ¹³ C-labeled substrate compound is ¹³ C-pantoprazole.
3) A ¹³ C-labeled substrate compound that is a substrate for CYP3A4 and CYP2C19 and has the ability to generate ¹³ CO ₂ by CYP2C19 after administration to mammals, or a preparation containing the same, is administered to a test mammal and excreted into the breath ¹³ A method for measuring the metabolic function of CYP3A4, comprising a step of measuring a CO ₂ emission pattern.
4) The method further comprises evaluating the ¹³ CO ₂ excretion pattern excreted in the exhaled breath or the pharmacokinetic parameter obtained therefrom by comparing it with the corresponding excretion pattern or parameter in a healthy mammal having normal CYP3A4 metabolic function. Method for measuring metabolic function of CYP3A4 in 3) above.
5) The method for measuring the metabolic function of CYP3A4 according to 3) or 4) above, wherein the ¹³ C-labeled compound is ¹³ C-pantoprazole.
6) A ¹³ C-labeled substrate compound having the ability to become a substrate for CYP3A4 and CYP2C19 and to generate ¹³ CO ₂ by CYP2C19 after administration to mammals, or a preparation containing the same, is administered to a subject, and ¹³ CO discharged in the breath _A method for measuring the presence or absence of a decrease in the metabolic function of CYP3A4 in a subject, comprising the steps of measuring ₂ excretion patterns and evaluating the resulting ¹³ CO ₂ excretion pattern in the subject or pharmacokinetic parameters obtained therefrom .
7) A method for measuring the presence or absence of an abnormality in the metabolic function of CYP3A4 in 6) above, wherein the ¹³ C-labeled compound is ¹³ C-pantoprazole.
8) A method for selecting a subject to participate in a clinical trial for measuring the effectiveness of a compound for preventing or treating a disease having the following steps:
(A) administering to a subject a ¹³ C-labeled substrate compound or a preparation containing the same, which becomes a substrate for CYP3A4 and CYP2C19 and has the ability to generate ¹³ CO ₂ by CYP2C19 after being administered to a mammal;
(B) measuring the emission pattern of ¹³ CO ₂ discharged in the exhalation of the subject,
(C) comparing the ¹³ CO ₂ excretion pattern measured in step (b) above with the corresponding excretion pattern in healthy individuals with normal CYP3A4 metabolic function,
(D) classifying according to a metabolic phenotype selected from the group consisting of a failing metabolite, an intermediate metabolite and a normal metabolite based on the comparison in step (c), and (e) normal in step (d) Subjects classified as metabolizers are selected as clinical trial participants.
9) Describes a ¹³ C-labeled substrate compound that becomes a substrate for CYP3A4 and CYP2C19 and has the ability to generate ¹³ CO ₂ by CYP2C19 after administration to mammals, a preparation containing the same, a breath collection bag, and a method for measuring CYP3A4 metabolic function A kit containing written instructions.
10) A test animal is administered with a ¹³ C-labeled substrate compound and a test substance, which becomes a substrate for CYP3A4 and CYP2C19 and has the ability to generate ¹³ CO ₂ by CYP2C19 after being administered to a mammal, and excreted during expiration ¹³ A method for evaluating the presence or absence or degree of affinity of the test substance for CYP3A4, comprising the step of measuring the presence or absence or degree of increase in CO ₂ .

The measurement method of the present invention is non-invasive and only requires the subject to perform a breath test. Further, since it does not require a highly trained technician for performing the test and does not require an advanced analyzer, it can be carried out at a general doctor's office.
Therefore, according to the present invention, it is possible to reduce the burden on the subject, and to measure and evaluate the presence or absence of a decrease in the metabolic function of CYP3A4 in a simple, quick and safe manner. The in vivo measurement of the CYP3A4 metabolic function is a useful index for classifying individuals with respect to drug reactivity, side effects, or optimal dosage. In addition, the measurement method of the present invention has an advantage that it can be evaluated whether or not the metabolic function of CYP3A4 is lowered, and at the same time, whether or not the metabolic function of CYP2C19 is lowered.

The figure which shows the expiration curve of a ¹³ C-pantoprazole breath test in the presence of erythromycin.

(A) CYP3A4 Metabolic Function Measuring Agent The ¹³ C-labeled substrate compound, which is an active ingredient of the CYP3A4 metabolic function measuring agent of the present invention, becomes a substrate for both CYP3A4 and CYP2C19, and generates ¹³ CO ₂ by CYP2C19 after administration to mammals. Have the ability to

Here, examples of mammals include animals, for example, domestic animals such as dogs and cats, cows, sheep, pigs, horses, monkeys, rats, mice, guinea pigs and the like.
Further, administration is not limited to the route, and may be oral or parenteral.

Such a ¹³ C-labeled substrate compound has the ability of at least one carbon atom in the molecule to be metabolized by CYP2C19 to produce stable ¹³ CO ₂ , and specifically, an N-methyl group or O— Examples thereof include a methyl group which is demethylated by CYP2C19, and the released methyl group is oxidized and finally discharged as ¹³ CO ₂ into the breath.

A typical example of such a ¹³ C-labeled substrate compound is ¹³ C-pantoprazole. ¹³ C-pantoprazole produces 4-hydroxypantoprazole and ¹³ CO ₂ by demethylation of the 4-position methoxy group of the pyridine ring by CYP2C19 as shown below. On the other hand, it is oxidized by CYP3A4 to produce a sulfone body.

The labeling method for obtaining the ¹³ C-labeled substrate compound is not particularly limited, but the conventional method (Sasaki, "5.1 Application of Stable Isotopes in Clinical Diagnosis": Journal of Japanese Chemistry 107, "Application of Stable Isotope in Medicine, Pharmacy, and Biology ", pp. 149-163 (1975), Nanedo: Kajiwara, RADIOISOTOPE, 41, 45-48 (1992)). ¹³ C-pantoprazole, which is particularly useful in the present invention, is commercially available from Cambridge Isotope Laboratories, Inc. (Andover, MA, USA).

As shown in Examples below, when ¹³ C-pantoprazole was metabolized in mice in the presence of a compound that blocks the metabolic pathway of CYP3A4, such as erythromycin, the amount of ¹³ CO ₂ in the breath was the capacity of erythromycin. Increase depending on.
Therefore, a compound such as ¹³ C-pantoprazole, which becomes a substrate for both CYP3A4 and CYP2C19 and has the ability to generate isotope-labeled CO ₂ by CYP2C19 after administration to mammals, is administered to test mammals and excreted into the breath. It is possible to determine whether or not CYP3A4 has a reduced metabolic function by measuring ¹³ CO ₂ and measuring the degree of increase.
That is, a ¹³ C-labeled substrate compound that becomes a substrate of CYP3A4 and CYP2C19 and has the ability to generate ¹³ CO ₂ by CYP2C19 after administration to mammals is used to measure or evaluate CYP3A4 metabolic function in individual test mammals. It can be a function measuring agent. By using the ¹³ C-labeled substrate compound or a preparation containing the same, measurement of metabolic behavior of CYP3A4 in a test mammal, evaluation of metabolic function, and clinical response and / or normality regarding CYP3A4 activity in the test mammal・ Abnormality can be identified.

The agent for measuring metabolic function of CYP3A4 of the present invention may be a single preparation of the above ¹³ C-labeled substrate compound, or may be formulated together with a pharmaceutically acceptable carrier.
The formulation can be formulated to be compatible with its intended route of administration. Examples of routes of administration include parenteral (eg, intravenous, intradermal, subcutaneous), oral (eg, inhalation), transmucosal, and rectal administration.
The dosage form may be any form suitable for the purposes of the present invention, examples of which are injections, intravenous injections, suppositories, eye drops, nasal drops, and other parenteral forms; and Liquids (including syrups), suspensions, emulsions, tablets (which may be uncoated or coated), capsules, tablets, powders, fine granules, granules and other oral forms. Oral compositions generally contain an inert diluent or an edible carrier.

When the formulation is a tablet, useful carriers include, for example, lactose, sucrose, sodium chloride, glucose, urea, starch, calcium carbonate, sodium bicarbonate and potassium, kaolin, crystalline cellulose, silicic acid, and other excipients Agents; simple syrups, glucose solution, starch solution, ceratin solution, carboxymethylcellulose, shellac, methylcellulose, potassium phosphate, polyvinylpyrrolidone and other binders; dried starch, sodium alginate, agar powder, laminaran powder, carbonic acid Sodium hydride, calcium carbonate, polyoxyethylene sorbitan, fatty acid ester, sodium lauryl sulfate, stearic acid monoglyceride, starch, lactose and other disintegrants; sucrose, stearic acid, cocoa butter, hydrogenated oil, and other Disintegration inhibitors; quaternary ammonium bases, sodium lauryl sulfate, and other absorption enhancers; glycerin, starch, and other wetting agents; starch, lactose, kaolin, bentonite, colloidal silicate, and other absorbents; and Examples include purified talc, stearate, boric acid powder, polyethylene glycol, and other lubricants.
The tablets can have a normal coating (such as sugar-coated, ceratin-coated, or film-coated tablets), a bilayer coating, or a multilayer coating.

  In the case of a capsule, the active ingredient and any of the above carriers are mixed, and the mixture is prepared by a predetermined method such as filling a hardened gelatin capsule or soft capsule.

  When the formulation is a suppository, useful carriers include, for example, polyethylene glycol, cocoa butter, higher alcohols, esters of higher alcohols, gelatin, semisynthetic glycerides and the like.

  When the above preparation is an oral liquid preparation, it is prepared by a predetermined method such as mixing an active ingredient and any commonly used carrier. Specific examples of oral solutions include syrup formulations. The syrup preparation does not need to be liquid, and may be a dry syrup preparation having a powder or granular form.

When the preparation is an injection, the injection solution, emulsion or suspension is preferably sterilized and isotonic with blood. Diluents useful for preparing the injection include, for example, water, ethyl alcohol, macrogol, propylene glycol, ethoxylated isostearyl alcohol, polyoxylated isostearyl alcohol, and polyoxyethylene sorbitan fatty acid ester. .
The injection may contain a sufficient amount of sodium chloride, glucose or glycerin to make an isotonic solution. Ordinary solubilizers, buffers, soothing agents and the like can also be added to the injection.

  Furthermore, a pharmaceutically acceptable additive such as a colorant, a preservative, a flavoring agent, a fragrance improving agent, a taste improving agent, a sweetening agent, or a stabilizer is added to the preparation of any dosage form. Can do. The above carriers and additives can be used alone or in combination.

The proportion of the ¹³ C-labeled substrate compound of the present invention contained in the formulation is not particularly limited, but may be about 0.1% to about 99% by weight of the total dry weight of the composition. This ratio can be suitably adjusted within the above range.
The amount of the ¹³ C-labeled substrate compound of the present invention per unit dose of the above preparation varies depending on the type of the active ingredient, but a preferable amount is, for example, 1 to 300 mg / person per unit dose.

(B) Metabolic function measurement of CYP3A4, evaluation of disease state or clinical response According to the present invention described above, a ¹³ C-labeled substrate compound having the ability to generate ¹³ CO ₂ by CYP2C19 after administration to a mammal (simply referred to as “ ¹³ C-labeled substrate”) CYP3A4 enzyme is obtained by administering a compound (also referred to as “compound”) or a preparation containing the compound (“agent for measuring metabolic function of CYP3A4”) to a test mammal and then measuring the excretion pattern of ¹³ CO ₂ excreted in exhaled breath. Activity (that is, CYP3A4 metabolic function) can be indirectly measured and evaluated. Therefore, the present invention provides such a metabolic function measurement method for CYP3A4.

In the CYP3A4 metabolic function measurement method of the present invention, the “test mammal” preferably means a subject who is a mammal such as a human, but in addition to humans, animals such as domestic animals such as dogs and cats, bovines, etc. Sheep, pigs, horses, monkeys, rats, mice, guinea pigs, and the like.
Further, administration is not limited to the route, and may be oral or parenteral.

¹³ CO ₂ discharged into the exhaled breath can be measured spectroscopically by any method known in the art, for example, infrared spectroscopy, or can be measured using a mass analyzer. Then, the discharge pattern (including discharge amount, discharge rate, change over time and ratio) is measured.
A typical example of a ¹³ CO ₂ measuring instrument is the UBiT-IR300 infrared spectrometer, commercially available from Meratek (Denver, Colorado, USA).
If a specific measurement procedure is given, for example, exhalation is collected from a subject who has been administered the ¹³ C-labeled substrate compound of the present invention or a preparation containing the same using an exhalation collection bag or the like. It is attached to an external spectrometer (for example, UBiT-IR300). The infrared spectrometer then measures the ratio of ¹³ CO ₂ to ¹² CO _{2 in} exhaled breath. By comparing the measurement result with the result of exhalation before administration of ¹³ C-labeled substrate compound labeled with standard or ¹³ C, the amount of ¹³ CO ₂ excreted can be substantially calculated.

The ¹³ CO ₂ excretion pattern thus measured is compared with the corresponding excretion pattern in healthy mammals with normal CYP3A4 metabolic capacity. That is, the CYP3A4 metabolic function in the test mammal is, for example, the ¹³ CO ₂ emission pattern obtained by the above measurement (the behavior of the emission amount or the emission rate with time) and the ¹³ CO ₂ emission in the standard measured by the same method. It is evaluated by comparing with the pattern.
Also, instead of or in addition to the ¹³ CO ₂ emission pattern, the area under the curve (AUC), the discharge rate (especially the initial discharge rate), the maximum discharge concentration (C _max ), the dose recovery as a function of time, Or a delta ¹³ CO ₂ slope as a function of time, a delta (DOB) to baseline at a specific time point derived from an emission pattern (emission transition curve) in a test mammal, or a similar parameter (preferably a pharmacokinetic parameter ) Is compared with the corresponding parameter in the standard. Here, the standard is the excretion pattern observed in one or more healthy mammals with normal metabolic capacity.

Thus, the ¹³ CO ₂ excretion pattern excreted in exhaled breath or the pharmacokinetic parameter obtained therefrom is compared with the corresponding excretion pattern or parameter (standard) in a healthy mammal with normal CYP3A4 metabolic function, When the value is higher than the standard, it can be evaluated that the metabolic function of CYP3A4 is decreased, and the degree of the decrease (insufficient metabolism, intermediate metabolism, normal metabolism, etc.) can be evaluated together. In addition, when the said measured value is lower than a standard, it can be evaluated that the metabolic function of CYP2C19 has fallen.

Furthermore, by using the method for measuring metabolic function of CYP3A4 of the present invention, it is possible to select subjects to participate in a clinical trial for measuring the effectiveness of a compound for preventing or treating a disease. Specifically, it is performed according to the following steps (a) to (e).
(A) administering to a subject a ¹³ C-labeled substrate compound or a preparation containing the same, which becomes a substrate for CYP3A4 and CYP2C19 and has the ability to generate ¹³ CO ₂ by CYP2C19 after being administered to a mammal;
(B) measuring the emission pattern of ¹³ CO ₂ discharged in the exhalation of the subject,
(C) comparing the ¹³ CO ₂ excretion pattern measured in step (b) above with the corresponding excretion pattern in healthy individuals with normal CYP3A4 metabolic function,
(D) classifying according to a metabolic phenotype selected from the group consisting of a failing metabolite, an intermediate metabolite and a normal metabolite based on the comparison in step (c), and (e) normal in step (d) Subjects classified as metabolizers are selected as clinical trial participants.

(C) Kit The kit for measuring CYP3A4 metabolic function of the present invention is a substrate for CYP3A4 and CYP2C19, and contains a ¹³ C-labeled substrate compound having the ability to generate ¹³ CO ₂ by CYP2C19 after administration to mammals. Preparations, breath collection bags for collecting exhaled breath, instructions describing how to measure CYP3A4 metabolic function, and the like.
^{The 13} C-labeled substrate compound or a preparation containing the same can be supplied as a tablet, powder, granule, capsule or solution. The instructions include those describing how to measure CYP3A4 metabolic function using the area under the curve, slope or other pharmacokinetic parameters described above. The kit may further contain a CYP3A4 modifying agent.

(D) Evaluation of the presence or absence of affinity for CYP3A4 or the degree thereof A test substance is a ¹³ C-labeled substrate compound and a test substance which have the ability to become CYP3A4 and CYP2C19 substrates and to generate ¹³ CO ₂ by CYP2C19 after administration to mammals. To evaluate the presence or absence of affinity of the test substance for CYP3A4 by measuring the presence or degree of increase in ¹³ CO ₂ excreted into the exhaled breath, that is, the test substance is a ¹³ C-labeled substrate compound Can be screened as a CYP3A4 inhibitor that inhibits the binding of CYP3A4 to CYP3A4, or the degree of affinity of the test substance for CYP3A4 can be evaluated.
For example, when a test substance and ¹³ C-pantoprazole are administered, if the amount of ¹³ CO ₂ excreted in the breath increases compared to the case where only ¹³ C-pantoprazole is administered, the test substance is 3A4. It can be said that it is a substrate. Further, by changing the dose of the test substance, by the ¹³ CO ₂ rate of change is compared with the ¹³ CO ₂ rate of change upon administration of known CYP3A4 substrates erythromycin etc., affinity for CYP3A4 of the test substance The strength of the can be evaluated.

Example 1
1) Animals used: Mice (n = 3) BALB / C ♀ 8 weeks old Non-fasting (weight: about 18g)
2) Various metabolic inhibitors: Prepare ¹³ C-pantoprazole mixed solution. (20μmol / 8mL as ¹³ C-pantoprazole)

3) Experimental method Each administration solution was prepared at 4 mL / kg, and ¹³ C-pantoprazole and each inhibitor were mixed at a ratio of 1: 1 before administration (control was a mixture of physiological saline and ¹³ C-pantoprazole). Liquid).
After collecting pre-exhalation, administer 8 mL / kg of the administration solution into the mouse tail vein (material used: needle 30G, 1 mL syringe, polytube SP10), before administration of ¹³ C-pantoprazole, and after administration, 10, 20, 30 Breaths were collected at 10 minute intervals up to 40 minutes, 50 minutes, and 60 minutes.
<Preparation of administration solution>
(A) ¹³ C-pantoprazole (20 μmol / 4 mL) MW: 433
¹³ C-pantoprazole (Cambridge Isotope Laboratories, Inc. Andover, Mass., USA) was weighed 6.49 mg, and distilled water for injection (OTSUKA PHARMACEUTICAL CO., LTD. Tokyo, Japan) was added to make 3 mL.
(B) Erythromycin (10 mg / 4 mL, 13.6 μmol / 4 mL) MW: 733.93
"Erythrosine for injection" (erythromycin is 500mg / 1 vial, ABBOTT JAPAN CO., LTD. Tokyo, Japan) Add 10mL of distilled water for injection (OTSUKA PHARMACEUTICAL CO., LTD. Tokyo, Japan) to 50mg / mL. Prepared. This 50 mg / mL solution was diluted 20-fold (1 mL was measured and 19 mL of physiological saline (OTSUKA PHARMACEUTICAL CO., LTD. Tokyo, Japan) was added).
(C) Erythromycin (20 mg / 4 mL, 27.2 μmol / 4 mL) MW: 733.93
"Erythrosine for injection" (erythromycin is 500mg / 1 vial, ABBOTT JAPAN CO., LTD. Tokyo, Japan) Add 10mL of distilled water for injection (OTSUKA PHARMACEUTICAL CO., LTD. Tokyo, Japan) to 50mg / mL. Prepared. This 50 mg / mL solution was diluted 10-fold (1 mL was measured and 9 mL of physiological saline (OTSUKA PHARMACEUTICAL CO., LTD. Tokyo, Japan) was added).
(D) Erythromycin (40 mg / 4 mL, 54.4 μmol / 4 mL) MW: 733.93
"Erythrosine for injection" (erythromycin is 500mg / 1 vial, ABBOTT JAPAN CO., LTD. Tokyo, Japan) Add 10mL of distilled water for injection (OTSUKA PHARMACEUTICAL CO., LTD. Tokyo, Japan) to 50mg / mL. Prepared. This 50 mg / mL solution was diluted 5-fold (1 mL was measured and 4 mL of physiological saline (OTSUKA PHARMACEUTICAL CO., LTD. Tokyo, Japan) was added).
(E) Erythromycin (100 mg / 4 mL, 136 μmol / 4 mL) MW: 733.93
"Erythrosine for injection" (erythromycin is 500mg / 1 vial, ABBOTT JAPAN CO., LTD. Tokyo, Japan) Add 10mL of distilled water for injection (OTSUKA PHARMACEUTICAL CO., LTD. Tokyo, Japan) to 50mg / mL. Prepared. This 50 mg / mL solution was diluted 2-fold (1 mL was measured and 1 mL of physiological saline (OTSUKA PHARMACEUTICAL CO., LTD. Tokyo, Japan) was added).
(F) Erythromycin (200 mg / 4 mL, 272 μmol / 4 mL) MW: 733.93
"Erythrosine for injection" (erythromycin is 500mg / 1 vial, ABBOTT JAPAN CO., LTD. Tokyo, Japan) Add 10mL of distilled water for injection (OTSUKA PHARMACEUTICAL CO., LTD. Tokyo, Japan) to 50mg / mL. Prepared.

Mice were held in the breath collection folder. Using a 20 mL disposable syringe attached to a three-way stopcock, exhaled air was collected at a rate of 20 mL at a rate of about 2 mL / s. About 11 mL of the collected breath was transferred to a vacuum test tube (LABCO LIMITED HIGH WYCOMBE), and the ¹³ C-carbon dioxide concentration in the breath was measured with ABCA-G (mass spectrometer for breath analysis: PDZ-Europa Ltd).

4) Results As shown in FIG. 1, the amount of ¹³ CO ₂ excreted into the exhaled air by the action of CYP2C19 increased depending on the volume of erythromycin.

Claims (5)

An agent for measuring metabolic function of CYP3A4, which contains pantoprazole in which the 4-position methoxy group of the pyrimidine ring is ¹³ C-labeled . After the pantoprazole or a preparation containing the pantoprazole was administered to a mammal, it was excreted into the breath ¹³ CO ₂ The metabolic function measuring agent according to claim 1, wherein an excretion pattern is measured. The metabolic function measuring agent according to claim 1 or 2, which measures the presence or absence of a decrease in metabolic function of CYP3A4. The metabolic function measuring agent according to any one of claims 1 to 3, which is used for selecting a subject to participate in a clinical test for measuring the effectiveness of a compound for preventing or treating a disease. A kit for measuring CYP3A4 metabolic function , comprising pantoprazole labeled with ¹³ C in the 4-position methoxy group of the pyrimidine ring or a preparation containing the pantoprazole , a breath collection bag, and instructions describing a method for measuring CYP3A4 metabolic function .

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