JP7604415B2 - Test fish oral administration device - Google Patents

Description

The present invention relates to a test fish oral administration device for administering a test substance directly orally to test fish.

In recent years, zebrafish have been attracting much attention as experimental animals. Zebrafish are small fish with a body length of about 40 mm. A syringe is generally used as a test fish oral administration device used for directly orally administering a test substance to a small test fish such as a zebrafish. That is, such a test fish oral administration device includes a syringe that encloses the test substance and a thin tube part that causes the test substance supplied from the syringe to flow out from an opening at the tip. Then, in an intubation state in which the thin tube part is inserted into the oral cavity of the test fish, the test substance that flows out from the tip of the thin tube part is directly orally administered to the test fish. In this application, the insertion of the thin tube part into the oral cavity of the test fish may be simply called "intubation".
The thin tube portion attached to the syringe generally uses a needle-shaped member made of a rigid metal or a flexible tube member called an oral probe.

When a test fish oral administration device, which is a rigid needle-shaped member attached to a syringe as the thin tube portion, is used to orally administer the test fish by inserting the needle-shaped member into the oral cavity of the test fish, the needle-shaped member is rigid and is likely to damage the stomach or intestines of the test fish. If the needle-shaped member is inserted too shallowly into the oral cavity of the test fish for fear of this happening, the test substance that flows out from the tip of the needle-shaped member will leak out of the body through the gills without reaching the stomach or intestines of the test fish.
On the other hand, when a test fish oral administration device, which is formed by attaching a tube member capable of being used as the thin tube portion to a syringe, is used to orally administer the test fish in an intubated state by inserting the tube member into the mouth of the test fish, the tube member is flexible, so that even if the intubation depth is relatively deep to reduce leakage from the gills, the burden on the stomach and intestines of the test fish is reduced. However, since it is difficult for the user who performs the intubation to know how deep the tube member has been intubated into the test fish, it is difficult to set the intubation depth appropriately, and there is a risk of damage to the stomach and intestines of the test fish or leakage of the test substance from the gills. In addition, when the thin tube portion is made of a flexible tube member, the shape of the tube member is unstable, making it difficult to intubate the mouth of the test fish, and further, the tube member may be bent near the mouth of the test fish, hindering the flow of the test substance.
In light of this situation, the main objective of the present invention is to provide a technology for a test fish oral administration device for directly orally administering a test substance to a test fish, which enables stable and accurate intubation while minimizing damage to the stomach and intestines of the test fish, thereby enabling the test substance to be appropriately orally administered to the test fish.

The first characteristic configuration of the present invention is a test fish oral administration device comprising a syringe for enclosing a test substance, and a thin tube portion for causing the test substance supplied from the syringe to flow out from a tip thereof, and for orally administering the test substance flowing out from the tip of the thin tube portion directly to the test fish in an intubation state in which the thin tube portion is inserted into the oral cavity of the test fish,
the thin tube portion comprises a rigid needle-shaped member connected to the syringe and a flexible tube member whose base end side is connected to the tip side of the needle-shaped member,
The base end side of the tube member is externally fitted and connected to the tip side of the needle-shaped member, and the base end of the tube member is set to an intubation depth indicator that is positioned near the mouth of the test fish in the intubation state.

According to this configuration, the tube member is connected to the tip side of the needle-shaped member with a part of the base end side of the tube member fitted over a part of the tip side of the needle-shaped member. The base end of the tube member is then located on the outer surface of the tip part of the needle-shaped member and is visible from the outside as a step whose diameter changes. The base end of the tube member that is visible in this way is set as an intubation depth indicator that is positioned near the mouth of the test fish, such as the lower jaw or upper jaw, in an intubation state in which the thin tube part is inserted into the oral cavity of the test fish.
Thus, while visually checking the base end of the tube member, which serves as an intubation depth indicator, the user can easily and accurately intubate the tube member, the base end of which is connected to the tip side of the needle-shaped member, into the oral cavity of the test fish so that it is positioned near the mouth of the test fish. Then, since the mating portion between the base end side of the tube member and the tip side of the needle-shaped member is rigid, it is held in a stable state in the oral cavity of the test fish, and the flexible tube member located on the tip side of the mating portion passes through the gills of the test fish without bending in a stable state, and is intubated at an appropriate intubation depth that suppresses damage to the stomach and intestines.
Therefore, the present invention provides a technology for a test fish oral administration device for directly orally administering a test substance to a test fish, which enables stable and accurate intubation while minimizing damage to the stomach and intestines of the test fish, thereby enabling the test substance to be appropriately orally administered to the test fish.

A second characteristic configuration of the present invention is that the test fish is a zebrafish,
The length of the fitting portion between the base end side of the tube member and the tip end side of the needle-like member is set within a range of 1 mm to 5 mm.

According to this configuration, when a zebrafish with a body length of approximately 50 mm is used as a test fish and a tube member having a base end externally fitted onto the tip end of a needle-shaped member is inserted into the oral cavity of the test fish, the length of the fitting portion between the base end of the tube member and the tip end of the needle-shaped member can be set within the range of 1 mm to 5 mm, thereby preventing damage to the test fish in a stable state.
That is, if the fitted portion is less than 1 mm, the joining stability of the tube member to the needle member decreases, causing problems such as the tube member accidentally falling off the needle member during intubation.
On the other hand, if the above-mentioned fitting portion is more than 5 mm, when the intubation state is achieved with the intubation depth indicator, which is the base end of the fitting portion, positioned near the mouth of the test fish, there is a risk that the rigid fitting portion will reach the esophagus side of the test fish and cause injury.

The third characteristic feature of the present invention is that the tube member is configured to be detachable from the needle-shaped member so that it can be replaced with another tube member.

With this configuration, the tube member is configured to be detachable from the needle-shaped member, so the tube member can be easily replaced with one of a different length or a new one.

FIG. 1 shows the overall configuration of the test fish oral administration device 1 and the intubation state of the test fish F. FIG. 1 is an enlarged cross-sectional view of a thin tube portion 10 in a test fish oral administration device 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings
As shown in Figure 1(a), the test fish oral administration device of this embodiment (hereinafter referred to as "this oral administration device") 1 comprises a syringe 2 for sealing a test substance, and a thin tube section 10 for causing the test substance supplied from the syringe 2 to flow out from an opening at the tip, and is configured as an instrument for directly orally administering the test substance flowing out from the opening at the tip of the thin tube section 10 to the test fish F when the thin tube section 10 is inserted into the oral cavity of the test fish F in an intubation state as shown in Figure 1(b).
In the thin tube portion 10 of the oral administration device 1 shown in FIGS. 1 and 2, the syringe 2 side (right side in the drawings) is called the base end side, and the opposite side to the syringe 2 (left side in the drawings) is called the tip side.
In addition, in this oral administration device 1, various dimensions such as the size of the syringe 2 and the bore of the thin tube portion 10 are set for a test fish F that is the subject of oral administration and is a small zebrafish with a body length of about 40 mm.

This oral administration device 1 is configured so that, when the thin tube portion 10 attached to the syringe 2 is inserted into the oral cavity of the test fish F, the device can stably and accurately intubate the test fish F while minimizing damage to the stomach and intestines, allowing the test substance to be appropriately orally administered to the test fish F. Details of this configuration are explained below.

That is, as shown in FIG. 2, the thin tube portion 10 of the oral administration device 1 is composed of a needle-shaped member 11 made of a rigid metal connected to the syringe 2, and a flexible tube member 12 called an oral probe, the base end 12b of which is connected to the tip 11a of the needle-shaped member 11.
Furthermore, the base end 12b side of the tube member 12 is fitted and connected to the tip end 11a side of the needle-like member 11. This provides a fitting portion 20 between the base end 12b side of the tube member 12 and the tip end 11a side of the needle-like member 11. This fitting portion 20 has its shape maintained and its rigidity maintained by the needle-like member 11 inserted therein.
Furthermore, the base end 12b of the tube member 12, which is the base end of the fitting portion 20, is exposed and visible as a step with a changing diameter on the outer surface of the tip 11a of the needle-shaped member 11. The base end 12b of the tube member 12, which is visible from the outside in this manner, is set as an intubation depth indicator A that is positioned near the mouth Fa, such as the lower jaw, of the test fish F in the intubation state shown in Figures 1(b) and 2. Although not shown, the tube member 12 itself or its base end 12b can be colored to improve the visibility of the intubation depth indicator A (base end 12b) on the outer surface of the needle-shaped member 11.
In this embodiment, the mouth Fa which is the positioning target of the intubation depth indicator A is the lower jaw of the test fish F, but it may be the upper jaw of the test fish F or another area near the mouth.

A user who orally administers a test substance to a test fish F using the oral administration device 1 configured as described above can easily and accurately intubate the tube member 12, whose base end 12b is connected to the tip 11a of the needle-shaped member 11, into the oral cavity of the test fish F so that it is positioned near the mouth Fa of the test fish F, as shown in Figures 1(b) and 2, while visually checking the base end 12b of the tube member 12, which serves as the intubation depth indicator A.
In such an intubation state, the rigid fitting portion 20 is stably held in the oral cavity of the test fish F. The flexible tube member 12 located at the tip side of the fitting portion 20 is intubated at an appropriate intubation depth that passes through the gills of the test fish F without bending in a stable state and prevents damage to the stomach and intestines.

Referring to Figure 2, the length L20 of the mating portion 20 is set within the range of 1 mm to 5 mm in order to suppress damage to the test fish F in a stable state, assuming that the test fish F is a small zebrafish with a body length of approximately 40 mm.
In other words, if the length L20 of the fitting portion 20 is less than 1 mm, the joining stability of the tube member 12 to the needle-shaped member 11 decreases, causing problems such as the tube member 12 accidentally falling off the needle-shaped member 11 during intubation.
On the other hand, if the length L20 of the above-mentioned fitting portion 20 exceeds 5 mm, when the intubation depth indicator A, which is the base end of the fitting portion 20, is positioned near the mouth Fa of the test fish F, there is a risk that the rigid fitting portion 20 will reach the esophagus side of the test fish F and cause injury.

Furthermore, the tube member 12 is configured to be detachable from the needle-shaped member 11 so that it can be replaced with another tube member. This allows the tube member 12 to be easily replaced with one of a different length or a new one.
With regard to the length (total length) L12 of the tube member 12, in order to properly orally administer the test substance to the test fish F while preventing damage to the stomach or intestines, it is desirable to set the length to about 10 mm when the test fish F is an adult zebrafish with a body length of about 40 mm, and it is desirable to set the length to about 7.5 mm when the test fish F is a juvenile zebrafish with a body length of about 30 mm.

[Another embodiment]
Other embodiments of the present invention will be described below. Note that the configurations of the embodiments described below are not limited to being applied alone, but may also be applied in combination with the configurations of other embodiments.

(1) In the above embodiment, the needle-shaped member 11 is made of metal, but it may be made of resin, for example, as long as it is rigid. Also, in the above embodiment, the tube member 12 is made of a commercially available oral probe, but it may be made of any flexible material.

(2) In the above embodiment, the test fish F is a zebrafish, but the test fish oral administration device 1 can also be applied to other test fish. In that case, the length L20 of the fitting portion 20 and the length L12 of the tube member 12 can be appropriately set according to the body length, the length of the digestive organs, etc. of the test fish F.

(3) In the above embodiment, the tube member 12 is detachable from the needle-shaped member 11. However, for example, the tube member 12 and the needle-shaped member 11 may be bonded to each other at the mating portion 20 so that they cannot be detached.

Reference Signs List 1: Test fish oral administration device 2: Syringe 10: Thin tube portion 11: Needle-shaped member 11a: Tip 12: Tube member 12b: Base end 20: Fitting portion A: Intubation depth indicator F: Test fish Fa: Mouth tip

Claims (2)

A test fish oral administration device comprising a syringe for enclosing a test substance and a thin tube portion for causing the test substance supplied from the syringe to flow out from a tip thereof, the thin tube portion being inserted into the oral cavity of a test fish in an intubation state, for orally administering the test substance flowing out from the tip of the thin tube portion directly to the test fish,
the thin tube portion comprises a rigid needle-shaped member connected to the syringe and a flexible tube member whose base end side is connected to the tip side of the needle-shaped member,
a base end side of the tube member is externally fitted and connected to a tip end side of the needle-shaped member , and a fitting portion between the base end side of the tube member and the tip end side of the needle-shaped member is provided in a state in which the tip end side of the needle-shaped member is inserted into the base end side of the tube member ,
The base end of the fitting portion is set to an intubation depth indicator that is positioned near the mouth of the test fish in the intubation state , and the fitting portion between the base end side of the tube member and the tip side of the needle-shaped member is held in the mouth of the test fish in the intubation state,
The test fish is a zebrafish,
A test fish oral administration device in which the length of the mating portion between the base end side of the tube member and the tip end side of the needle-shaped member is set within the range of 1 mm to 5 mm . 2. A test fish oral administration device as described in claim 1 , wherein the tube member is configured to be freely attached and detached to the needle-shaped member so that it can be replaced with another tube member.

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