JP4626940B2 - Relaxin secretion promoter - Google Patents

Description

  The present invention relates to a relaxin secretion promoter.

In animals raised by humans, such as livestock and pets, various breeds have been improved to obtain the required form, properties, and performance. While livestock animals with the ability are created, the ability inherent in the animal is partially weakened to affect productivity. In particular, the decline in reproductive capacity is the subject of research as an issue to be improved.
The decline in fertility in livestock production is a decline in fertility, implantation, parturition, and lactation. In general, in the livestock industry, there are many forms of pursuing performance such as meat quality and meat production in male animals and reproductive performance in female animals. This is because female animals are involved in all stages of reproduction from fertilization to weaning of offspring, and thus the difference in their reproductive ability has a great influence on productivity.
In pig farming, various varieties and breeding methods have been improved because production of more piglets efficiently leads to a reduction in production costs.
By the way, although the pregnancy period of pigs is almost constant and difficult to shorten, as a method for improving so that the pregnancy period can be shortened from the time of delivery to the next pregnancy period, for example, fructo-oligo There is a method of promoting estrus recurrence using a breeding sow breeding feed containing a saccharide mainly composed of sugar (Patent Document 1).
In addition, it is important to prevent the occurrence of premature infants. As a method for preventing such premature infants, for example, using a breeding sow breeding feed containing saccharides mainly composed of oligosaccharides such as fructooligosaccharides, There is a method of reducing the occurrence rate of (Patent Document 2).

JP-A-63-14665 JP-A-8-23889

In pigs that are prolific animals, the number of fetuses per abdomen has increased as a result of efforts to improve techniques to increase the number of fetuses, such as techniques to increase fertilization rate and techniques to increase the implantation rate. In general, more than 10 piglets are produced in one parturition.
However, if the number of litters is large, the time required for delivery tends to be long, and there is a tendency for the number of stillborns to be delivered at the end to increase, and the number of piglets produced per litter. In order to increase this, it is absolutely necessary to reduce the number of stillbirths and increase the number of live births.
As a method for reducing stillbirth, for example, there is a method that enables delivery care to mother pigs that have become difficult to deliver by synchronizing the delivery using prostaglandin F2α as a delivery inducer (Non-patent Document 1). ), Delivery care has a problem that the administrator must always accompany the pig during the delivery time, which is a work burden.
In addition, regarding pregnancy hormones, for example, relaxin administration to pigs before parturition can result in rapid delivery of the fetus and increase the number of viable fetuses (Non-patent Document 2). In humans, relaxin, Alternatively, it is known that prorelaxin can be used parenterally and can be used as a route adjustment drug during delivery (Patent Document 3).

Pig farming friend August 2002 issue, p. 53-56 “Clinical Veterinary” special issue, VoL. 20, No. 3, 2002, p. 151-159 JP-A-63-152399

However, at present, there is still no technique for further exhibiting the above-mentioned properties such as the production route adjusting action of relaxin.
As a result, the development of technology that contributes to safe delivery as well as the improvement of the breeding ability is awaited.

  The subject of this invention is providing the technique which increases the number of the piglets produced by one delivery with the technique which contributes to a safe delivery with the improvement of a reproduction capability.

  The inventors of the present invention have made extensive studies to solve the above-mentioned problems. Although it is a pregnancy hormone important for parturition, it has been found that relaxin is promoted by a specific oligosaccharide, and as a result of further research, the present invention has been completed.

The present invention comprises the following inventions.
1. Relaxin secretion promoter for feeding to sows whose main component is isomaltoligosaccharide.
2. 2. The relaxin secretion promoter according to 1 above, wherein the isomaltoligosaccharide is one or more of isomaltose, isomaltotriose, or panose.
3. 3. A method for preventing parturition accompanied by abnormalities resulting from narrowing of the birth canal and insufficient softening / expansion of the cervix, etc., characterized in that the relaxin secretion promoter according to 1 or 2 above is used. 4). A method for giving birth to a pig, characterized in that the relaxin secretion promoter according to 1 or 2 above is used for the birth of a pig.

The fact that isomaltoligosaccharide has an action of promoting the secretion of relaxin is an epoch-making discovery found in the present invention, and this point has significance of the present invention.
That is, the present invention is characterized in that isomaltoligosaccharide is used to promote the secretion of relaxin, but blood relaxin during delivery has the effect of promoting delivery and shortening the delivery time of the fetus. Therefore, if this relaxin secretion promoter is fed to a pregnant female animal, the blood relaxin concentration at the time of delivery can be increased, and delivery can be terminated safely and promptly.

The present invention has been made based on the following findings.
(1) Relaxin is present in pregnant animals and is a type of peptide hormone that promotes relaxation of the pubic ligament and muscles around the pelvis and relaxation of the cervix. In addition, it has been found that there are various biological effects such as an inhibitory action of excessive uterine contraction movement, promoting uterine growth and increasing water content, and promoting mammary gland development.
(2) The present applicant has previously developed a relaxin-like protein secretion promoter mainly composed of oligosaccharides such as isomaltoligosaccharide for the purpose of enhancing the reproductive ability of male animals (Japanese Patent Application 2003-2003). 78807).
(3) Although the above invention relates to a male animal, it was thought that isomaltoligosaccharides may also have a secretion promoting action on relaxin present in pregnant female animals. It was found that isomaltoligosaccharide has an action of promoting the secretion of relaxin.
(4) Then, further research was continued, and the present inventors finally succeeded in developing a relaxin secretion promoter mainly composed of isomaltoligosaccharide.

If the relaxin secretion promoter of the present invention is fed to a pregnant female animal, it can increase the blood relaxin concentration at the time of delivery and terminate the delivery safely and promptly.
In particular, in the case of pigs, when the number of pups is large, the time required for delivery tends to be long, and there is a tendency for the occurrence of stillbirth of pups delivered at the end to increase. If it is granted, the economic effect will be great, as it will be possible to reduce stillbirth.
In any case, since the relaxin secretion promoter mainly composed of the isomaltoligosaccharide of the present invention has an action of promoting the secretion of relaxin, the characteristics of relaxin, for example, the relaxing action of muscles around the pubic ligament and pelvis And the cervical canal relaxing action can prevent abnormal labor, prevent stillbirth, and give birth to a special effect.
In addition, since the isomaltooligosaccharide, which is an active ingredient of the relaxin secretion promoter of the present invention, has been recognized as safe and has no problem in terms of safety, the promoter can be used safely for humans. is there.

Hereinafter, the present invention will be described in more detail.
The relaxin secretion promoter of the present invention contains isomaltoligosaccharide as an active ingredient.
Therefore, the use of relaxin, isomalto-oligosaccharide, secretagogue, etc. will be described.

(1) Relaxin Relaxin is an important pregnancy hormone that is involved in setting the environment where the fetus can be born and raised safely after pregnancy, as described below.

1) Structure Relaxin is named after it is detected in pregnant animals and relaxes the pelvic ligament and dilates the birth canal. The structure has been revealed in about 20 kinds of animals such as humans. Each is a polypeptide consisting of two chains of A and B chains, the molecular weight is around 6000, structurally similar to insulin, and one intramolecular disulfide at cysteine (Cys) at positions 6 and 11 of the A chain. The (SS) bond forms an intermolecular SS bond at two positions of Cys at the 7th position of the A chain and the 7th position of the B chain and the 20th position of the A chain and the 19th position of the B chain.

2) Expression site (animals that require ovaries throughout the entire pregnancy)
Corpus luteum: rats, mice, pigs, cattle Placenta: dogs, rabbits, hamsters (animals that do not require ovaries for a certain period of time)
Corpus luteum: human placenta: cat, horse Uterus: guinea pig

3) Release Rat, Pig: Begins to rise from the middle of pregnancy, reaches a maximum value 1-2 days before parturition, and decreases rapidly after parturition.
Humans and monkeys: As low as 1 ng / ml throughout pregnancy, especially after reaching a maximum at 10 weeks, gradually decreases until delivery.
Dogs, cats, horses: rises from mid-pregnancy and remains constant until just before delivery.

4) Action (I) Pubic bone connection Relax the pubic bone connection, widen the birth canal and speed up the delivery of the fetus.
(B) Uterus Promotes uterine growth, suppresses myometrial contraction, promotes vascular dilation and renewal, and maintains a uterine environment suitable for fetal growth.
(C) Cervical region Prior to delivery, the cervix is softened and expanded to speed up fetal delivery.
(D) Mammary gland Prior to delivery, the mammary gland develops and expands to prepare for suckling.
(E) Placenta Promote alteration of connective tissue in the maternal-fetal boundary region.

5) Other (related diseases)
Infertility, gonadal dysfunction, skin sclerosis, peripheral vascular disease, cardiovascular disease, renal dysfunction and the like have been pointed out.

(2) Isomalt-oligosaccharides Isomalt-oligosaccharides are oligosaccharides containing α-1,6 bonds in the structure. Examples of the oligosaccharide include isomaltose, isomalttriose, isomalttetraose, panose, etc. Should be used.
Since isomaltooligosaccharides are highly stable against heat and acid, there is little inactivation due to heat treatment of feed or addition of acidic agents, so relaxin secretion promoters made of isomaltoligosaccharides are not limited in their use. It is advantageous.

(3) Use 1) Applied animal The relaxin secretion promoter of this invention is applicable regardless of the kind if it is a female animal in which the presence of relaxin is confirmed. Examples thereof include livestock animals such as pigs, rats, mice, cows, dogs, rabbits, hamsters, cats, horses, guinea pigs, pets, test animals, humans, and the like.

2) Form of use Since the relaxin secretion-promoting agent of the present invention can be administered orally, it can be used as it is or in the form of a formulation, and can also be contained in feeds, foods or pharmaceuticals.
As a preparation, it can be formed in the form of a solid preparation such as a powder, granule, capsule, tablet, or a liquid preparation.
In formulating, various additives can be used. For example, an excipient | filler, a disintegrating agent, a nutrient, a herb (herbal medicine), a live fungus agent, etc. are mentioned.
Excipients include silicic acid, zeolite, calcium carbonate, calcium phosphate, sugar (lactose, sucrose, mannitol, sorbitol, etc.), starch (corn starch, wheat starch, rice starch, potato starch), cellulose derivatives (methylcellulose, hydroxypropyl) Methyl cellulose, sodium carboxymethyl cellulose, polyvinyl pyrrolidone, etc.), gelatin, tragacanth gum, etc., disintegrating agents are cross-linked polyvinyl pyrrolidone, agar, alginic acid or salts thereof, and nutritional agents are amino acids (lysine, methionine, threonine, tryptophan, valine). Etc.), vitamins (folic acid, biotin, retinol, β-carotene, α-tocopherol, etc.) and the like, and examples of viable bacteria include lactic acid bacteria, lactobacilli, bifidobacteria, natto bacteria, etc. .

3) Administration It is sufficient that administration of the relaxin secretion promoter of the present invention is started from the second trimester when secretion of relaxin begins. For livestock animals such as pigs, this can be done by adding to the mixed feed.
The dose is about 0.01 to 0.3 g / day / kg body weight as isomaltoligosaccharide, but the effect is preferably 0.02 to 0.2 g / day / kg body weight.
It is desirable to continuously and continuously supply the relaxin secretion promoter.

(4) Others Natural delivery is normal, but in the case of economic animals, planned delivery may be performed using a delivery inducer such as prostaglandin F2α (PGF).

(1) According to the present invention, the release of relaxin in the blood at the time of delivery is promoted, so that the relaxin action, that is, the pubic bond is relaxed to widen the birth canal, the cervix is softened / expanded, etc. Since the phenomenon occurs sufficiently, an effect of a safe delivery, for example, an effect such as quick delivery, suppression of dystocia, reduction of stillbirth, etc. is achieved.
In addition, by promoting the secretion of relaxin, the growth of the uterus is promoted, and the suppression of the uterine muscle contraction movement and the expansion and renewal of blood vessels are promoted, thereby maintaining the uterine environment suitable for the growth of the fetus.
Furthermore, by promoting the secretion described above, the mammary gland develops and expands, and the postpartum lactation ability is improved.
(2) The present invention is optimally applied to prolific animals such as pigs.
(3) Since the isomaltooligosaccharide which is an active ingredient of the relaxin secretion promoter of the present invention is a safe substance, the promoter can be used for humans.
When this relaxin secretion enhancer is applied to humans, it is possible to prevent the unfortunate occurrence of a born child with a disability, which is caused by narrowing of the birth canal and insufficient softening / dilation of the cervix. Will be played.
(4) The relaxin secretion promoter of the present invention is advantageous because it can be administered orally.

  Hereinafter, although an example etc. are given and the present invention is explained still in detail, the present invention is not limited to these.

<Measurement of relaxin concentration>
The relaxin concentration was measured according to a time-resolved fluorescence immunoassay established as a method for measuring relaxin concentration (Non-patent Document 2).

(1) Preparation of tracer After using purified relaxin and labeling with non-radioactive fluorescent substance europium, fractionation by gel filtration is performed to obtain relaxin labeled with europium.

(2) Preparation of relaxin-specific antibodies Relaxin-specific antibodies are prepared by immunizing rabbits.
The obtained antibody reacts only with relaxin, does not react with other hormones such as insulin, LH and FSH at all, and has extremely high specificity.

(3) Time-resolved fluorescence immunoassay (TR-FIA)
The relaxin concentration is measured by the following method using a time-resolved fluorescence immunoassay based on the competitive principle in which the second antibody is immobilized.
The sample used for measurement is generally blood (serum), but urine may be used.
The sample or standard and relaxin-specific antibody are added to the microtiter plate on which the second antibody is immobilized, and incubated for 1.5 hours. Europium labeled relaxin is then added as a tracer and incubated for an additional 3.5 hours. After the incubation is complete, the plate is washed 6 times to stop the reaction. Thereafter, an enhancement reagent (NaN ₃ ) is added to form a chelate compound exhibiting high fluorescence by releasing europium ions from the labeled relaxin. After 5 minutes of incubation, the fluorescence is counted with a time-resolved fluorometer.

Example 1
69 parts of isomaltoligosaccharide syrup (Isomalt 900: Showa Sangyo Co., Ltd.) containing 33% isomaltose, 14% isomaltorose, 7% isomaltose, 6% isomalttetraose as an active ingredient Was added to 31 parts of silicic acid (manufactured by United Silica Industrial Ltd.), followed by stirring and drying to prepare a relaxin secretion promoter containing isomaltoligosaccharide as an active ingredient.
Next, the above relaxin secretion promoter was added to the feed and fed to sows, and the time course of the relaxin concentration in blood at the time of delivery was examined while comparing with the control group without addition.

(1) Test method Five test groups and control groups were selected so that the mother pig's line and birth history would be the same.
In the test group, the isomaltoligosaccharide was fed with a feed supplemented with 0.3% of the present secretion promoter so as to be 0.03 to 0.06 g / day / kg body weight. On the other hand, in the control group, feed containing no secretagogue was fed.

(2) Survey items Blood was collected 15 days before, 2 days before, 1 day before, and on the day of delivery in the second trimester when the relaxin concentration fluctuated rapidly, and the relaxin concentration in the serum was measured. We also investigated the incidence of stillbirths during delivery.

(3) Results Table 1 shows the relaxin concentration in the sow serum and the stillbirth rate at delivery.

From the results in Table 1, the following can be understood.
(1) There is no difference in the blood relaxin concentration until 2 days before delivery, but the test section is higher on the day before and on the day of delivery when the relaxin concentration rises rapidly.
(2) The rate of stillbirth, which indicates the safety of childbirth, is clearly lower in the test area.
(3) Prostaglandin F2α (PGF) is administered on the day before parturition, and a rapid increase in relaxin concentration may indicate an increase in sensitivity to PGF.
From the above, it was confirmed that the relaxin secretion promoter of the present invention promotes the secretion of relaxin.

The relaxin secretion-promoting agent of the present invention achieves a safe delivery effect, for example, an effect such as rapid delivery, suppression of dystocia, reduction of stillbirth, etc. It is best to apply to.

Claims (4)

Relaxin secretion promoter for feeding to sows whose main component is isomaltoligosaccharide.   The relaxin secretion promoter according to claim 1, wherein the isomaltoligosaccharide is one or more of isomaltose, isomaltotriose, or panose. 3. A method for preventing parturition accompanied by abnormalities resulting from narrowing of the birth canal and insufficient softening / expansion of the cervix in the birth of pigs, characterized in that the relaxin secretion promoter according to claim 1 or 2 is used. A method for giving birth to pigs, characterized in that the relaxin secretion promoter according to claim 1 or 2 is used for the birth of pigs.