JPH053798A - Measurement of physical fatigue degree and quantitative analysis of lactic acid in urine - Google Patents

Abstract

PURPOSE:To readily and sensitively measure the degree of physical fatigue and to enable ready measurement even in a home toilet, etc., by quantitatively analyzing lactic acid in urine. CONSTITUTION:For example, lactate oxidase is acted on lactic acid in urine in the presence of oxygen and the amount of consumed O2 is quantitatively analyzed by using a computer through an oxygen electrode placed in the urine liquid, thus measuring the objective degree of fatigue. In addition, a small-sized detector used in this method can be incorporated directly into a toilet stool in a home toilet to enable measurement even at home.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the degree of physical fatigue and a method for quantitative analysis of lactic acid in urine. BACKGROUND OF THE INVENTION Knowing the amounts of components in urine is a useful method for obtaining information on the state of a living body. Therefore, it has been customary to inspect urine components in hospitals and the like.

By the way, urine test items do not include lactic acid test. Conventionally, a metabolic system in which lactic acid is biosynthesized from pyruvic acid in muscle tissue under lack of oxygen is known, and it can be imagined that lactic acid produced in the body also appears in urine, but lactic acid in urine is It is not necessarily considered to be pathological because it is contained, and this is considered to be one of the reasons why the quantitative analysis of lactic acid is not included in the urine test items.

As a test for lactic acid, it is usual to use blood as a target, and therefore, lactic acid in blood is conventionally clinically measured.

Here, the present invention focuses on urine as a measurement target of lactic acid.

Generally, as a method for analyzing a biological substance in a body fluid such as urine or blood, an absorbance measuring method in which a test liquid is irradiated with light having a specific wavelength and the absorbance is measured is widely used.

However, in the case of this method, the pretreatment for the sample preparation and the measuring operation itself are very complicated and the measuring time is long, and they are easily affected by contaminants, and an expensive light source and spectroscopic device are required. Therefore, there is a problem that the entire device becomes large and the price is expensive.

[0007] Therefore, this method is not suitable for measuring urinary lactic acid at home. In other words, it is recently envisaged to install a measuring device in a toilet of a home or the like to measure urinary components, but it is difficult to realize this as long as the above method is used.

[0008]

The present invention has been made to solve the above problems, and is characterized by measuring the degree of physical fatigue by quantitatively analyzing lactic acid in urine. . In addition, as a quantitative analysis method of lactic acid in urine,
Lactic acid in the urine is reacted with the collected urine in the presence of oxygen to react lactic acid in the urine, and the degree of the reaction is measured to quantitatively analyze the urinary lactic acid.

[Action and Effect of the Invention] The present inventor focused on urine as a measurement target of lactic acid and conducted various experiments. As a result, a significant correlation was found between the amount of lactic acid in urine and physical fatigue. It turned out that there is. That is, there is a large difference between the amount of lactic acid in urine in normal times and the amount of lactic acid in urine after exercise,
Moreover, it was revealed that the amount of lactic acid that appears in urine is proportional to the magnitude of exercise.

Therefore, according to the present invention, the degree of physical fatigue can be measured by quantitatively analyzing the amount of lactic acid in urine,
Can contribute to health management.

Further, the present invention utilizes an enzyme that specifically reacts with lactic acid as a method for measuring urinary lactic acid, and therefore, it is possible to quantitatively analyze urinary lactic acid with high sensitivity by excluding the influence of other contaminants. Can

When lactate oxidase is allowed to act on lactic acid in urine in the presence of oxygen according to the present invention, oxygen is consumed and pyruvic acid and hydrogen peroxide are produced as shown in Formula 1.

[0013]

[Chemical 1]

Therefore, the degree of reaction, that is, the amount of lactic acid in urine can be determined by detecting the consumption of oxygen in the reaction system or by detecting the production of hydrogen peroxide.

In this case, it is possible to immerse the oxygen electrode in the liquid and electrically detect the consumption of oxygen by the oxygen electrode. Alternatively, the hydrogen peroxide electrode can be immersed in the liquid, and the amount of hydrogen peroxide produced can be electrically detected by the hydrogen peroxide electrode.

In this way, the amount of lactic acid in urine can be electrically measured, and the amount of lactic acid can be immediately known by the calculation processing by the computer.

If these methods are adopted, the measuring device for urinary lactic acid can be made compact and inexpensive, and a series of measurements can be automated. Therefore, it can be used in a toilet at home. It is also possible to install it directly in the toilet bowl at.

In this case, the user of the toilet bowl can easily know the amount of lactic acid in urine simply by adding the need, and at the same time, can know the fatigue level of the body.

If the degree of fatigue can be known just by adding it at home or the like, the degree of fatigue of the body can be tracked throughout the day or daily life, which is extremely useful information for health management.

As a method for detecting the degree of lactic acid oxidation reaction by an enzyme, it is possible to use a method other than the above example. For example, a method of detecting chemiluminescence of luminol known as a luminol reaction by a predetermined weak photodetector can be used.

In this luminol reaction, luminol is oxidized by hydrogen peroxide using peroxidase as a catalyst to cause chemiluminescence.

At this time, if the amount of luminol and the catalyst is excessive, the reaction is determined by the amount of hydrogen peroxide, and therefore the amount of hydrogen peroxide produced can be indirectly detected by measuring the emission intensity. It is possible to know the degree of lactic acid oxidation reaction under the action of lactate oxidase.

[0023]

Embodiments of the present invention will now be described in detail with reference to the drawings. In FIG. 1, 10 is a constant temperature bath, 12 is a reaction vessel, and 14 is an oxygen supply pipe for supplying oxygen into the liquid in the vessel.

Reference numeral 16 is a stirrer, and reference numeral 18 is a galvanic cell type oxygen electrode, which includes a Pt cathode 20 and a Pb anode 22.

Reference numeral 24 is an enzyme-immobilized membrane mounted on the surface of the oxygen electrode 18, which is obtained by immobilizing lactate oxidase on the dialysis membrane using glutaraldehyde by a crosslinking method.

The oxygen electrode 18 is an ammeter (or voltmeter) 2
It is connected to the computer 28 via 6 and the electric signal taken out is processed.

In this embodiment, first, 45 ml of 0.1 M phosphate buffer solution (pH 7) was placed in the container 12 in the constant temperature bath 10 and kept at 40 ° C. In order to keep the oxygen concentration in the liquid constant, The dissolved oxygen concentration in the liquid was kept constant by blowing air.

When the dissolved oxygen concentration became constant, 5 ml of a standard solution containing lactic acid having a known concentration was added and the decrease value of the current was obtained. Then, the same operation was performed for standard solutions having different concentrations, and the relationship between the decreased current value and the concentration of lactic acid was obtained. The results are shown in Figure 2.

As is clear from the figure, it was confirmed that there was a clear linearity between the amount of lactic acid and the decreasing current value in the range of lactic acid concentration up to 8 mg / dl.

Next, based on this calibration curve, an attempt was made to quantitatively analyze the lactic acid concentration before and after exercise. That is, urine of a healthy adult male before exercise and urine after exercise (exercise was carried out by going up and down 3 steps of a staircase in a 5 story building) and collecting 5 ml of the diluted urine (normal urine sample: 10 times dilution). After exercise, sample urine: 150-fold diluted) was injected, and the lactic acid concentration in urine was measured based on the calibration curve. The results are shown in Table 1.

[0031]

[Table 1]

For comparison, the concentration of glucose in urine before and after exercise was also measured. The results are also shown in Table 1.

As is clear from this result, the amount of glucose before and after exercise does not change so much that it is about 1 to 1.4 times, while the amount of lactic acid explodes to about tens to 100 times before and after exercise. Are increasing. From this, it can be seen that the degree of fatigue of the body can be known by quantitatively analyzing lactic acid in urine.

FIGS. 3 and 4 show an example in which a measuring device for urinary lactic acid is constructed according to the present invention and is attached to a toilet bowl, in which 30 is a Western-style toilet and 32 is a measuring device unit. is there.

The concrete construction of the measuring device unit 32 is shown in FIG. In this figure, 34 is a buffer solution prepared under the optimum conditions for the enzymatic reaction, which is held in the container and is sent to the passage 38 by the pump 36.

On the other hand, in the toilet bowl 30, the urine collecting cylinder 40
The urine sample liquid collected in (1) is sent by the pump 42 and introduced into the passage 38 via the electromagnetic valve 44.

Then, the buffer solution and the urine sample solution are sufficiently mixed in the reaction coil 46 to cause the reaction,
Then, the amount of oxygen consumed by the reaction or the amount of hydrogen peroxide produced is detected by the oxygen electrode or the hydrogen peroxide electrode 48 and taken out as a current value.

The extracted current is amplified by the amplifier 50, converted into a digital signal by the A / D converter, and then input to the computer 52 for arithmetic processing. The calculation result is displayed on the display 54.

According to the method of this example, urinary lactic acid can be automatically measured by simply adding the amount to the toilet in the home or the like, and the toilet user can add the amount without performing any special operation. You can automatically know the degree of fatigue of each body.

Although the embodiment of the present invention has been described in detail above, this is merely an example, and the present invention can be carried out in a mode in which various modifications are made based on the knowledge of those skilled in the art without departing from the spirit of the invention. is there.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a method for quantitatively analyzing lactic acid in urine, which is an example of the present invention.

FIG. 2 is a diagram showing the relationship between the lactic acid concentration and the reduced current value obtained in the same example.

FIG. 3 is a diagram showing an example in which a measuring device is constructed according to the present invention and is attached to a toilet bowl.

FIG. 4 is a diagram showing a specific configuration example of the measuring device unit.

[Explanation of symbols]

18 Oxygen electrode 24 Enzyme-immobilized membrane 40 Urine collection cylinder

Claims (5)

[Claims] 1. A method for measuring the degree of physical fatigue, which comprises measuring the degree of physical fatigue by quantitatively analyzing lactic acid in urine. 2. Urine characterized in that urine lactic acid is reacted with lactic acid in the urine in the presence of oxygen to react the lactic acid in the urine, and the extent of the reaction is measured to quantitatively analyze the urine lactic acid. Method for quantitative analysis of lactic acid in milk. 3. The lactic acid in urine is quantitatively analyzed by measuring the amount of oxygen consumed by the reaction or by measuring the amount of hydrogen peroxide produced. Method for quantitative analysis of lactic acid in urine. 4. The quantitative analysis method for lactic acid in urine according to claim 3, wherein the oxygen electrode is immersed in a liquid and the amount of oxygen consumed is detected by the oxygen electrode. Method. 5. The method for quantitatively analyzing lactic acid in urine according to claim 3, wherein the hydrogen peroxide electrode is immersed in a liquid, and the generated hydrogen peroxide is detected by the hydrogen peroxide electrode. Method for quantitative analysis of lactic acid in milk.