JPS63296753A - Inhalation experimenting apparatus for experimental animal - Google Patents

Abstract

PURPOSE:To continuously calculate an administration amount with high accuracy, in an inhalation experimenting apparatus for an experimental animal, by detecting the spontaneous respiration cycle of the experimental animal on the basis of the change in the internal pressure of a nose part exposing apparatus and operating a valve in synchronous relation to said spontaneous respiration cycle. CONSTITUTION:The gaseous mixture from a constant concn. chamber 5 is introduced into a nose part exposing apparatus 9 in matching relation to the inhalation of an experimental animal 10 to enter the lungs. Continuously, when the experimental animal 10 performs exhala tion from the lungs by its own respiratory action, the pressure in the nose part exposing apparatus 9 becomes positive. When this positive pressure is detected by a pressure detector 16, control is performed so that a change-over valve 12 is opened and a change-over valve 17 is closed. By this mechanism, the gaseous mixture in the lung is discharged to a constant pressure chamber 13 in matching relation to the exhalation of the experimental animal 10. As mentioned aboved, in matching relation to the spontaneous respiration of the experimental animal 10, the opening and closing of the change-over valves 7, 12 are changed over, and inhalation and exhalation are automatically performed. The concn. of the substance to be tested in the gaseous mixture supplied to the nose part exposing apparatus 9 and the concn. of the substance to be tested in the gaseous mixture always measured by a particle densitometer 8 are always measured by a particle densitometer 11 and given to a data processing apparatus 17.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an inhalation experiment device for laboratory animals, and particularly to an inhalation experiment device for laboratory animals that lightly administers a particulate test substance to a small part of the laboratory animal. .

[Prior art] In inhalation experiments to examine the effects of drugs on living organisms by administering drugs to experimental animals such as dogs and rabbits, the test substance used as the drug is mixed in the air in the form of particles, and this mixed gas is will be supplied to experimental animals.

The main methods of feeding laboratory animals are the whole body exposure method, in which the whole body of the experimental animal is exposed to the test substance, and the nasal exposure method, in which only the nose is exposed to the test substance.

Among these methods, the nasal exposure method allows testing of high concentrations with a smaller exposure volume than the whole body exposure method.
It has been widely used in inhalation experiments with expensive or small test substances, and inhalation experiment devices for laboratory animals equipped with nasal exposure devices have been developed.

[Problems to be Solved by the Invention] However, the conventional inhalation experiment apparatus for laboratory animals has a problem in that it is not possible to accurately measure the amount of a test substance administered to the laboratory animal.

Precise dosages are very important data in this type of inhalation experiment.

In conventional devices, an exposure device is attached to a laboratory animal, the concentration of the test substance in the exposure device is first measured, and the average value of these measured values during the inhalation experiment is calculated and used as the average concentration value.

Then, a method is adopted in which the total dose of the test substance is estimated from the average respiration rate and average concentration value of the experimental animals.

However, the spontaneous respiration rate of experimental animals varies greatly depending on the experimental environment, and conventional devices cause considerable errors in estimated doses.

Another major problem was that conventional devices were unable to determine changes in dosage over time.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an inhalation experiment device for laboratory animals that can accurately measure the dose of a test substance to a laboratory animal.

[Means for Solving the Problems] A first feature of the present invention is a nasal exposure device for administering a test substance to the respiratory system of a laboratory animal in an inhalation experiment device for laboratory animals; A supply/exhaust device that supplies and exhausts air, and a supply/exhaust device? A test substance generator that mixes the test substance in the form of particles into the air supply path, an exhaust treatment device that purifies the test substance in the exhaust path, and a measurement that measures the concentration of the test substance in the air supply path and the exhaust path. The point is that a device is provided.

A second feature of the present invention is that, in an inhalation experiment apparatus for laboratory animals, there is provided a nasal exposure device for administering a test substance into the respiratory system of the laboratory animal, and a supply supply for supplying a mixed gas of the test substance to the nasal exposure device. a tube, a discharge tube for discharging a gas mixture of the test substance from the nasal exposure device, and a measuring device for continuously and separately measuring the concentration of the test substance in the supply tube and the discharge tube, respectively;
The present invention includes a data processing device that calculates the amount of the test substance to be administered to the experimental animal over time based on the difference between the two measurement results of the measuring device n.

A third feature of the present invention is that, in an inhalation experiment apparatus for laboratory animals, there is provided a nasal exposure device for administering a test substance into the respiratory system of the laboratory animal, and a supply supply for supplying a mixed gas of the test substance to the nasal exposure device. a discharge pipe for discharging the test substance mixture from the nasal exposure device, a supply valve provided between the supply pipe and the nasal exposure device, and a supply valve provided between the discharge pipe and the nasal exposure device. a pressure detector that detects the pressure within the nasal exposure device; and a valve control device that controls opening and closing of the supply valve and the discharge valve based on the detection results of the pressure detector. It is in.

[Operation] According to the first feature of the present invention, the test substance is mixed into the air supply device η in the form of particles, and is supplied to the experimental animal in the nasal exposure device.

Further, the test substance in the exhaust device is purified by the exhaust treatment device.

That is, air mixed with the test substance constantly circulates within the exposure device.

Furthermore, since the concentration of the test substance in the air supply path and the exhaust path is measured by the measuring device, it is possible to accurately calculate the administration:t.

According to a second feature of the invention, the test substance is supplied to the nasal exposure device through the supply tube and then discharged through the discharge tube.

That is, air mixed with the test substance constantly circulates within the exposure device.

Furthermore, the concentration of the test substance is measured separately in the supply pipe and the discharge pipe.

The dose of the test substance to be administered to the experimental animal is related to the difference between the constant concentrations on both sides, so the dose can be calculated accurately based on the constant concentrations on both sides.

Furthermore, since concentration measurements are always performed, it is also possible to determine changes in dosage over time.

According to the third feature of the present invention, the supply valve and the discharge valve attached to the nasal exposure device are controlled to open and close based on the pressure value within the nasal exposure device.

The pressure inside the nasal exposure device fluctuates due to the breathing of the experimental animal, but if the valve is controlled in synchronization with this fluctuation, it becomes possible to supply and exhaust air that matches the breathing of the experimental animal, and eliminates air mixed with the test substance. Circulation can occur within the nasal exposure device.

Therefore, by measuring the concentration of the test substance within this circulating cavity, accurate dosage calculations can be made over time.

[Example] The present invention will be described below based on illustrated embodiments.

The figure is a block diagram showing the configuration of an inhalation experiment apparatus for laboratory animals according to an embodiment of the present invention.

In the figure, solid lines between blocks indicate air movement paths, and broken lines indicate electrical signal transmission paths.

The compressor l is a device that supplies compressed air, and in this example, it supplies air at a pressure of −,5 to 10β
It has the ability to supply at a flow rate of /min.

The pressure regulating device 2 has a built-in air filter set mist separator, and purifies the compressed air supplied from the compressor 1, and also controls the pressure to 3 g/g by a pressure regulating valve.
cm'.

The particle generator 3 is a device that mixes a test substance into the supplied air, and in this embodiment, it is composed of a compressed air type nebulizer.

For example, a 1% /V sodium chloride aqueous solution is used as the test substance, and mist-like particles are created and mixed into the air.

This mixed air is heated and dried by the heating device 4.

Here, the moisture in the mist is removed from the air and solid test substance particles are formed.

This gas mixture is introduced into the constant concentration chamber 5.
The concentration of the test substance in the gas mixture in the constant concentration chamber 5 is measured by a particle concentration meter 6, and this measured value is fed back to the particle generator 3.

This feedback signal controls the operation of the particle generator 3 and maintains the test substance concentration in the constant concentration chamber 5 at a constant value.

The mixed gas in the constant concentration chamber 5 passes through a switching valve 7 and a particle concentration meter 8, and is led to a nasal exposure device 9.

The Urabe exposure device 9 is a mask-like inhalation device, and the experimental animal 10
It is set to 0 part of.

The experimental animal 10 will breathe into the gas mixture in the nose exposure device 9.

On the other hand, the mixed gas inside this nose exposure device 9 is
1 and a switching valve 12, to a constant pressure chamber 13, and further to an exhaust treatment bag r11+4 and an exhaust pump 15.
is discharged to the outside through the

The constant pressure chamber 13 has a built-in pressure regulating device, so that the exhaust flow rate can be kept constant.

The exhaust treatment device 14 has a built-in high-performance air filter and can purify the test substance in the mixed gas.

The exhaust pump 15 performs air intake for the above-mentioned exhaust system.

A pressure detector 16 is provided to measure the pressure within the shell exposure device 9, and the opening and closing of the switching valves 7 and I2 are controlled based on this detected value.

This opening/closing control is performed as follows.

That is, when the experimental animal 1o inhales into its lungs through its own breathing action, the pressure within the nose exposure device 9 becomes negative.

Therefore, when the pressure detector 16 detects this negative pressure, control is performed to open the switching valve 7 and close the switching valve 12.

As a result, the mixed gas from the constant concentration chamber 5 is introduced into the nasal exposure device 9 and enters the lungs of the experimental animal 10 in time with the inhalation of the experimental animal 10.

Subsequently, when the experimental animal IO exhausts air from its lungs through its own breathing action, the pressure within the nose exposure device 9 becomes positive.

Therefore, when the pressure detector 16 detects this positive pressure, control is performed to open the switching valve 12 and close the switching valve 7.

As a result, the mixed gas in the lungs is discharged into the constant pressure chamber 13 at the same time as the experimental animal 10 is exhausted.

In this way, the opening and closing of the switching valves 7 and 12 are switched in accordance with the spontaneous breathing of the experimental animal IO, and air supply and exhaust are automatically performed.

Test article 'f in the gas mixture supplied to the nasal exposure device 9
The fl concentration is constantly measured by a single particle concentration meter 8.
Further, the concentration of the test substance in the gas mixture discharged from the nose exposure device 9 is constantly measured by the particle concentration meter 11.

As each particle concentration meter, a dust concentration meter is used in this embodiment, and the concentration of particles passing through the pipe is continuously measured.

This measured value is provided to the data processing device 17.

The data processing device 17 calculates the difference between the constant values on both sides.

The difference in concentration values is due to the inhalation of the experimental animal 10, so from this difference the dose for the test animal can be determined by
can be determined with certainty.

Moreover, since this difference is obtained for each spontaneous breathing cycle of the experimental animal, it is also possible to determine changes in the dose over time.

Although the present invention has been described based on one embodiment, the present invention is not limited to the embodiment described herein, and each component may be replaced with other components as long as they perform the same function. It is also possible to realize this using the following equipment.

[Effects of the Invention] As described above, according to the present invention, in an inhalation experiment apparatus for laboratory animals, the spontaneous breathing cycle of the experimental animal is partially detected by pressure changes within the exposure device, and the valve is activated in synchronization with this spontaneous breathing cycle. By operating the C part exposure device, the mixed gas containing the test substance is circulated, and the dose is determined by measuring the concentration in the test animal before and after circulation, making it easier to calculate the dose. It will be possible to do this accurately and continuously.

[Brief explanation of drawings]

The figure is a block diagram showing the configuration of an inhalation experiment apparatus for laboratory animals according to an embodiment of the present invention. l...Compressor 2...Pressure adjustment device 3...Particle generator 4...Heating device 5...Constant concentration chamber 6, 8, I+...Particle concentration meter 7.12...Switching Valve 9...Nose exposure device jO...Experimental animal 13...Constant pressure chamber 14...Exhaust treatment device 15...Exhaust pump 16...Pressure detector 17...Data processing device

Claims (3)

[Claims] (1) A nasal exposure device that administers a test substance to the respiratory system of a laboratory animal, an air supply device that supplies air to the nasal exposure device, and an exhaust device that exhausts air from the nasal exposure device. a test substance generating device that mixes the test substance in the form of particles into the air supply path of the air supply device; an exhaust treatment device that purifies the test substance in the exhaust path of the exhaust device; and the air supply path. and a measuring device for measuring the concentration of a test substance in the exhaust passage. (2) a nasal exposure device for administering a test substance into the respiratory system of a laboratory animal; a supply pipe for supplying a gas mixture of the test substance to the nasal exposure device; and a supply tube for supplying the test substance from the nasal exposure device. A discharge pipe for discharging a mixed gas; a measurement device for continuously and separately measuring the concentration of the test substance in the supply pipe and the discharge pipe; An inhalation experiment device for laboratory animals, comprising: a data processing device that determines the dose of a test substance over time. (3) a nasal exposure device for administering a test substance to the respiratory system of a laboratory animal; a supply pipe for supplying a gas mixture of the test substance to the nasal exposure device; and a supply tube for supplying the test substance from the nasal exposure device. a discharge pipe for discharging the mixed gas; a supply valve provided between the supply pipe and the nose exposure device; a discharge valve provided between the discharge pipe and the nose exposure device; An experiment characterized by comprising: a pressure detector that detects the pressure within the nose exposure device; and a valve control device that controls opening and closing of the supply valve and the discharge valve based on the detection results of the pressure detector. Animal inhalation experiment equipment.