Preparation method of anorexia animal model for children and application thereof

Abstract

The application relates to a preparation method of an animal model of pediatric anorexia and application thereof, and belongs to the technical field of medicines. The model can be used for screening of medicines for treating children anorexia, pharmacological research and efficacy evaluation. The application first creatively adopts a modeling method of gradient increment gavage of erythromycin to successfully establish an animal model of children anorexia. The modeling method has the following advantages compared with a conventional high-fat high-protein fat feed feeding and central operation modeling method: modeling time is shortened; compared with other modeling methods, the modeling time cost is reduced by two weeks; economic cost is reduced; compared with high-fat high-protein feed which is relatively expensive, the cost of erythromycin medicine is 1 / 10 of that of the high-fat high-protein feed, and the reduction of time cost also reduces the cost of animal feeding; the operation technology is simple and convenient; compared with the preparation of a high-precision central anorexia animal model, the experimental operation technology is simple; the requirement for laboratory instruments and equipment is relatively low; the demand for experimental personnel is reduced, and the labor cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medicine, and particularly relates to a preparation method of an animal model of a common pediatric disease "infantile anorexia" in traditional Chinese medicine and application thereof. The model can be used for screening of drugs for treating infantile anorexia, pharmacological research, efficacy evaluation, and research on pathogenesis and pathological characteristics. BACKGROUND

[0002] In recent years, with the development of social economy and changes in lifestyle, new characteristics have appeared in the etiology and syndrome of infantile anorexia: in addition to common causes such as improper eating habits and long-term unreasonable dietary structure (for example: overeating, eating oily and sweet foods and various processed foods), changes in the living environment of children, conflicts in mother-child feeding interactions, frequent use of antibiotics and other drugs, addiction to electronic devices and lack of proper exercise have become important causes of infantile anorexia, and can also be seen in common pediatric psychological disorders such as attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and anxiety disorder. The characteristics of the etiology and syndrome of infantile anorexia in this era pose new requirements for the diagnosis and treatment of this disease in contemporary pediatric traditional Chinese medicine. Strengthening the research on the mechanism of infantile anorexia and co-morbid diseases and the research on the therapeutic efficacy has become a new challenge.

[0003] At present, the preparation methods of the animal model of infantile anorexia mainly include three types: 1. A special high-protein and high-fat feed is used to feed young rats to establish an animal model of infantile anorexia. This method is commonly used in the establishment of animal models of infantile anorexia. In the early stage of model establishment, this method was used. We found that on the 14th day, the 21st day and the 28th day of feeding with the special feed, the food intake of the model preparation rats was significantly reduced compared with the blank group; the body weight was slightly delayed compared with the change in food intake. However, when the model rats were fed with normal feed on the 29th day and the persistence of anorexia syndrome was observed, the food intake of the model preparation group began to increase rapidly, and the difference compared with the blank group lost statistical significance (P>0.05), and the body weight also recovered to the growth rate. The cause and mechanism of this phenomenon are not clear, but it is the starting reason for the development of a new preparation method of the animal model of infantile anorexia by our research group. 2. Spleen deficiency syndrome animal model: a small dose of leucogen is slowly administered to establish a mouse model of spleen deficiency. However, this drug is used in various animal models of diseases, and the final symptoms and diseases are different, so this model preparation method is still controversial. 3. Central anorexia animal model: leptin is injected into the lateral ventricle of the animal through a pre-installed cannula, which is used as an animal model of central anorexia. This model is consistent with the pathogenesis of anorexia, and provides a new idea for the research of anorexia. However, the mortality rate of rats with intracerebral cannula is high, and the experimental operation is complex, so the replication and application of this model are less. SUMMARY

[0004] The application aims to solve the problems of complex operation and poor simulation effect of the existing pediatric anorexia animal model, and provides a preparation method of a pediatric anorexia animal model and application thereof.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the application is as follows:

[0006] A preparation method of a pediatric anorexia animal model adopts a method of gradient increment gavage of erythromycin to establish the model; the specific method is as follows: starting from 0.04 g / one, gavage is performed on the animals, and the basic dose is increased by one time every 3 days; when the food intake of the rats is decreased by 20% to 30% or the body weight is lower than that of the control group by 10% to 15%, the pediatric anorexia animal model is obtained; the control group is gavaged with distilled water.

[0007] According to the state of the rats after taking medicine, such as food intake, body weight and fecal changes, during the experiment, the rats start to recover the body self-defense in two to three days, and the increment needs to be increased, and the change is found out, and the changes of food intake and body weight are closely observed.

[0008] Generally, acute poisoning phenomenon does not occur under the condition that the dose limit is not exceeded, the search of acute influence data of erythromycin shows that the oral LD50 (half lethal dose) of rats is 4600 mg / kg to 9272 mg / kg, the dose used in the research is small, but the shape of the feces of the rats is changed. Considering that the rats are three weeks old and the body weight is also relatively light, the large dose may be a short-term reaction, and the gradient increment can effectively maintain the decreased appetite and gastrointestinal discomfort of the rats, and the rats are converted into three-week-old rats, and the two-week time simulates the symptoms of decreased appetite and gastrointestinal discomfort of children after taking erythromycin for a long time.

[0009] Further, the animal is a rat.

[0010] Further, the rat is a male SPF level SD rat.

[0011] Further, the male SPF level SD rat is three weeks old and weighs between 60 and 80 g.

[0012] Further, all the rats in the modeling group and the control group can freely obtain food and water, the room temperature is (25±0.5) ℃, and the relative humidity is (55±5) %.

[0013] Further, compared with the control group, the pediatric anorexia animal model has the following significant changes:

[0014] The food intake is decreased by 20% to 30% or the body weight is decreased by 10% to 15%;

[0015] The appetite is decreased, the hair is rough, dull and lusterless, the rats are curled up and less active, and the feces are not shaped or are loose and watery;

[0016] The content of albumin (ALB) and total protein (TP) in serum is reduced, and the content of blood urea nitrogen (BUN), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and creatinine (Cr) is slightly increased;

[0017] A small amount of inflammatory factor infiltration, local congestion, and a small amount of epithelial cell shedding (erosion) can be observed in the gastric antrum tissue, and the epithelial cells in the mucosa layer are arranged more disorderly than those in the blank group.

[0018] And the above indexes still cannot recover to the normal level of the control group within two weeks after the modeling is completed, which is consistent with the clinical characteristics of anorexia for a long period, that is, the modeling is successful.

[0019] Application of the pediatric anorexia animal model as described above in the research on the pathogenesis, pathological characteristics, screening of related therapeutic drugs, pharmacological research and efficacy evaluation of pediatric anorexia.

[0020] The beneficial effects of the present application relative to the prior art are:

[0021] The method of the present application is simple and convenient to operate, can successfully establish a pediatric anorexia animal model in a short time, does not require expensive instruments and equipment, and does not require many research and development personnel, and is easy to reproduce; the fitting and stability are good, the present application has high fitting with the clinical manifestations (decrease in food intake and body weight, overall state, serum protein detected by gastric tissue HE observation, and protein reduction) of anorexia nervosa in children, and the standard feed can be continuously fed during modeling. The present application has a high experimental basis for the pathogenesis, clinical diagnosis and treatment, and new drug research and development of pediatric anorexia, and the modeling method is suitable for popularization and application.

[0022] The present application has the following advantages over the conventional high-fat high-protein fat feed and central surgery modeling methods: (1) shortening of modeling time: two weeks of modeling time cost is reduced compared to other modeling methods; (2) reduction of economic cost: compared to the expensive high-fat high-protein feed, the cost of erythromycin is 1 / 10 of that of the high-fat high-protein feed, and the reduction of time cost also reduces the cost of animal feeding; (3) simple and convenient operation technology: compared to the preparation of high-precision central anorexia animal models, the experimental operation technology is simple; the requirements for laboratory instruments and equipment are relatively low; the demand for experimental personnel is reduced, and the labor cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The figure is the shape of the feces of rats in different groups.

[0024] Figure 2 The figure is a comparison chart of food intake and body weight of rats in different groups during the modeling period.

[0025] Figure 3The comparison chart of the food intake and body weight of rats in different groups during the treatment period.

[0026] Figure 4 The comparison chart of the serum ALB and TP content of rats in different groups.

[0027] Figure 5 The comparison chart of the pathological analysis of gastric mucosa injury of rats in different groups (HE staining x100 and x200). DETAILED DESCRIPTION

[0028] The technical solutions of the present application will be described in detail below in combination with the drawings and examples, but the present application will not be limited in the scope of the described examples. The process parameters not mentioned in the examples of the present application can be performed according to conventional methods, and the raw materials used can be obtained through commercial channels.

[0029] Example 1

[0030] 1 Material

[0031] 1.1 Experimental animals

[0032] 24 male SPF SD rats, three weeks old, average body weight (60-80) g, purchased from Sibeifu (Beijing) Biotechnology Co., Ltd. (License No. SCXK (Jing) 2024-0001), caged breeding (4 rats / cage), all rats can freely obtain food and water, room temperature (25±0.5) ℃, relative humidity (55±5) %, 12h light and dark alternation lighting.

[0033] 1.2 Experimental drugs

[0034] Modeling drugs: erythromycin enteric-coated tablets (manufacturer: Xi'an Lijun Pharmaceutical Co., Ltd.; approval number: State Drug Standard Word H61021632; specification: 0.125g; batch number: 2301242040).

[0035] Treatment drugs: Yunsi Xiaoshi Granules, which are composed of Dangshen, Baizhu, Cangzhu, Fuling, Chenpi, Jineijin, Jiaoshanzha, Shencu, Maidan, Shanyao and Baibiandou, are made into granules by the Chinese Medicine Prescription Preparation Room of Shanxi Province Hospital of Integrated Traditional Chinese and Western Medicine.

[0036] 1.3 Main reagents

[0037] Albumin (ALB) assay kit, total protein (TP) assay kit, urea nitrogen (BUN) test kit, alanine aminotransferase (ALT / GPT) test kit, aspartate aminotransferase (AST / GOT) test kit, creatinine (Cr) assay kit (Nanjing Jiancheng, Cat. No. A028-2, A045-4, C013-2, C009-2, C010-2, C011-2); physiological saline, PBS solution (ASPEN, Cat. No. AS1087, AS1044); Eosin Y (alcohol soluble) (Xiya Reagent, Cat. No. D12621); hematoxylin (Sigma, Cat. No. H9627-25G); paraformaldehyde, anhydrous ethanol, dimethylbenzene, sodium chloride, sodium dihydrogen phosphate dihydrate, disodium hydrogen phosphate dodecahydrate, hydrochloric acid, sodium iodate, potassium aluminum sulfate dodecahydrate, citric acid monohydrate, glacial acetic acid, ammonia (National Pharmaceutical Group Chemical Reagent Co., Ltd., Cat. No. 80096618, 10009218, 10023418, 10019318, 20040718, 10020318, 10011018, 80117214, 10001060, 10007118, 10000218, 10002018); neutral gum (Solarbio, Cat. No. G8590).

[0038] 1.4 Main instruments

[0039] Microplate reader (Molecular Devices, Model: Cmaxplus); desktop centrifuge (Shanghai Anting Scientific Instrument Factory, Model: TGL-16c); refrigerated centrifuge (Hunan Xiangyi Laboratory Instrument, Model: TGL-16); ice maker (Changshu Xueke Electric Appliance Co., Ltd., Model: IMS-20); water bath (Jiangnan Instrument Factory, Jintan, Model: HH-W-600); constant temperature incubator (Shanghai Jinghong Experimental Equipment Co., Ltd., Model: GNP9160); ordinary optical microscope, inverted white light / fluorescent photographing microscope, upright white light photographing microscope (OLYMPUS, Model: CX21, IX51, CX31); imaging system (Q-IMAGING, Model: MicroPublisher).

[0040] 2 Methods

[0041] 2.1 Model establishment

[0042] After 3 days of adaptive feeding, the rats were divided into a blank group (n=8), a model group (n=8), and a drug treatment group (n=8) according to a random number table. The model group and the treatment group were given erythromycin by gavage, which was converted to 0.02 g per rat according to the body surface area method of a 60 kg adult. The gavage was performed with a reference dose of 0.04 g per rat, which was doubled every 3 days (i.e., 2 times, 3 times, 4 times, and 5 times of 0.04 g per rat). The gavage dose could be adjusted appropriately according to the food intake and body weight loss of the rats in the model group, as well as the changes in stool texture. The details are shown in Table 1. The blank group was given an equal volume of normal saline by gavage as a solvent control. The rats in the above groups were gavaged for a total of 14 days. The food intake of the rats was recorded every day for 24 hours, the body weight was measured twice a week, and the hair, tail, stool texture, and emotional activity of the rats were closely observed. According to the average decrease of 20% to 30% in food intake, or a decrease of 10% to 15% in body weight compared with the control group, the model was considered successful, which met the syndrome manifestations of pediatric anorexia in traditional Chinese medicine.

[0043] Table 1 Erythromycin gavage dose table

[0044] Days (d) 1d 4d 7d 10d 13d Body weight (g / each) 90～100 110～130 140～150 170～190 200～220 Dose (g / each) 0.04 0.08 0.12 0.16 0.20

[0045] 2.2 Drug intervention (treatment according to the prescription)

[0046] After the pediatric anorexia model was successfully established, the treatment group was given Yansu Xiaoshi Granules for intervention treatment by gavage, with a dose of 6.4 g / kg·d converted according to the body surface area method of a 60 kg adult, and a gavage volume of 1 mL / 100 g. The blank group and the model group were given normal saline by gavage as controls, and the gavage was continued for 14 days.

[0047] 2.3 Specimen collection

[0048] After the last administration, the rats were fasted and deprived of water for 12 hours, then anesthetized with 10% chloral hydrate, and immediately subjected to abdominal aortic blood sampling. After obtaining the whole blood sample, it was left to stand at room temperature for 30 minutes, then centrifuged at 3000 r / min for 10 minutes at 4°C to collect the supernatant, which was stored at -20°C for later use. After blood sampling, the rat antrum was quickly stripped and the blood on the tissue was washed off, and then fixed in 4% paraformaldehyde.

[0049] 3 Main observation indicators

[0050] 3.1 General physical observation

[0051] The general physical signs of the rats, such as the degree of luster and dullness of the hair and tail, emotional activity, fecal particle size, and softness, were observed.

[0052] 3.2 Monitoring of food intake and body weight

[0053] Daily timing of each cage enough amount of feed, the next day fixed time weighing the remaining amount of feed. Calculate the 24h food intake of rats, 24h food intake = original amount - remaining amount. The daily food intake of each rat is the food intake per cage divided by the number of rats 4. Body weight was weighed and recorded on Monday or Saturday morning every week.

[0054] 3.3 ELISA method for detecting the content of albumin (ALB), total protein (TP), urea nitrogen (BUN), alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine (Cr)

[0055] The content of serum ALB, TP, BUN, ALT, AST and Cr was detected by ELISA method. The experimental detection was carried out according to the kit instruction.

[0056] 3.4 HE staining of antral tissue pathological section observation

[0057] The antrum and its surrounding 1x1cm were taken, and the paraffin embedding section was cut. The section was deparaffinized, ethanol gradient hydrated, cell nucleus was dyed with hematoxylin dye, cytoplasm was dyed with eosin dye, gradient dehydration and transparency, and the tissue morphology was observed under optical microscope after neutral gum sealing.

[0058] 3.5 Statistical analysis

[0059] SPSS22.0 statistical software was used for statistical analysis, and the measurement data were represented as (x±s). The data conforming to normal distribution and equal variance were compared among multiple groups by one-way analysis of variance, and pairwise multiple comparisons were made by LSD-t test. The data not conforming to normal distribution or equal variance were compared among multiple groups by Kruskal-Wallis H test, and the comparison between two groups was made by Mann-Whitney U test, P<0.05 was considered statistically significant. The drawing software was GraphPad Prism8.

[0060] 4 Experimental results

[0061] 4.1 General observation of physical signs

[0062] General observation of physical signs showed that before modeling, the rats in each group were in good condition and had no abnormal performance. On the 4th-5th day of modeling, the model group rats had reduced food intake, rough and relaxed hair; occasional irritability, preferred to curl up; soft and loose stool, slightly greenish yellow in color; after treatment with Yansixiaoshig Granules, the hair was smooth and shiny, the reaction was sensitive, the activity was free, the stool was brown and dry, and the hardness was moderate, and tended to be normal (see Figure 1 ).

[0063] 4.2 Comparison of food intake and body weight of rats

[0064] 4.2.1 Comparison of food intake and body weight of rats during modeling period

[0065] Firstly, the success of model establishment was evaluated according to the comparison of body weight and food intake of rats during modeling period, and it was found that Figure 2 The food intake and body weight of rats in each group were in normal state before modeling. After modeling by erythromycin gavage, the food intake and body weight of rats in model group and treatment group showed a downward trend as a whole.

[0066] In the first week of modeling (modeling period I), compared with the blank group, the food intake of rats in model group and treatment group decreased slowly (P<0.01); the body weight decreased slowly with a slight lag (P<0.01).

[0067] In the second week of modeling (modeling period II), the food intake and body weight of rats in model group and treatment group began to decrease rapidly, and there was a significant difference compared with the blank group, with statistical significance (P<0.01), and the food intake was lower than 24.0%-25.7%, and the body weight was lower than 8.0%-10.4%, which did not rebound in a short time (within 10-14 days) to meet the requirements of preparation of pediatric anorexia model.

[0068] 4.2.2 Comparison of food intake and body weight of rats during treatment period

[0069] At the beginning of intervention treatment by Yunsixiao Granules (treatment period I), compared with the blank group, the food intake and body weight of rats in model group still showed a significant downward trend (P<0.01); compared with the model group, the food intake of rats in Yunsixiao Granules treatment group increased (P<0.05), and the body weight increased slowly. After the second week of intervention treatment (treatment period II), compared with the blank group, the food intake and body weight of rats in model group continued to decrease (P<0.01); compared with the model group, the food intake of rats in treatment group increased significantly (P<0.01), and the body weight increased synchronously, see Figure 3 .

[0070] 4.3 Detection results of related serum indicators

[0071] 4.3.1 Comparison of serum ALB and TP contents

[0072] Compared with the blank group, the contents of serum ALB and TP in model group decreased significantly (**P<0.01; *P<0.05), and after treatment by Yunsixiao Granules, the contents of serum ALB and TP in treatment group increased significantly ( # P<0.05), see Figure 4 .

[0073] 4.3.2 Comparison of serum BUN, ALT, AST and Cr contents

[0074] Compared with the blank group, the contents of BUN, ALT, AST and Cr in the model group were increased (P<0.05), but the numerical changes were in or close to the normal physiological value range of rats. After treatment with Yunsi Xiaoshi Granules, the contents of BUN, ALT, AST and Cr were decreased, and there was no significant difference compared with the model group (P>0.05), as shown in Table 2.

[0075] Table 2 Comparison of the contents of ALT, AST, BUN and Cr in the serum of rats (n=6, ±s)

[0076] Group BUN (mmol / L) ALT (U / L) AST (U / L) Cr (μmol / L) Blank group 6.5±1.7 12.8±4.8 30.9±16.0 37.6±10.4 Model group 9.0±1.1* 20.1±5.1* 55.4±18.4* 50.8±7.0* Medium dose group 8.8±1.1 19.9±6.7 47.8±19.7 45.0±4.8

[0077] Note: Compared with the blank group: *P<0.05; **P<0.01; compared with the model group: #P<0.05; ##P<0.01.

[0078] 4.4 Histopathological observation of antral tissue

[0079] A small amount of inflammatory factor infiltration was observed in the antral tissue of the model group rats, and the epithelial cells in the mucosal layer were more disordered than the blank group, and part of the epithelial cells were eroded and shed. The histopathological changes in the antral tissue of the treatment group rats were significantly improved, the structure gradually became complete, the glands increased and became full, and the inflammatory infiltration decreased, as shown in Figure 5 .

[0080] Based on the background status and the failure of high-protein and high-fat feed to establish the model, the present application considers using appropriate drugs to prepare the model. After screening, erythromycin, with its obvious gastrointestinal reaction and high toxicity threshold, becomes the first choice for model preparation drugs.

[0081] Erythromycin, as a motilin receptor (MTLR) agonist, mimics exogenous motilin in gastrointestinal contraction activity, directly stimulates gastrointestinal motility: low concentration of erythromycin can promote cholinergic activity to increase gastrointestinal peristalsis, while higher concentration can stimulate cholinergic function and directly contract the muscle, induce long-term and non-propulsive hypermotility of the antrum by contracting the gastric fundus, and cause symptoms such as nausea. Secondly, erythromycin is also a representative drug of macrolide antibiotics. Due to its spectrum of activity, it not only resists pathogens, but also targets the body's symbiotic bacteria, causing a sharp decline in the dominant bacteria of the intestinal tract, Bacteroides, disrupting the composition of the intestinal microbiota and causing ecological imbalance, and causing many gastrointestinal reactions. Therefore, the anorexia or aversion to eating caused by erythromycin is related to its dose. The gradient incremental administration of erythromycin can highly simulate the characteristics of reduced food intake in young rats for a long period of time, which is consistent with the above research conclusion, and at the same time overcomes the phenomenon of gastrointestinal adaptability and food intake recovery of rats with equal daily administration.

[0082] After the model is formed, the liver and kidney functions of the rat serum are detected, the serum ALB and TP are important indexes for reflecting the body nutrition level of children. Once protein-energy deficiency occurs, it rapidly decreases, and when protein-energy intake increases, it can obviously rise in 3 days, so it can rapidly reflect whether the nutrition intake is in positive balance or negative balance, and can be used as an index for rapidly reflecting the nutrition state. In combination with the present application Figure 4 , the food intake and body weight of the model preparation group of rats decrease, accompanied by the decrease of serum ALB and TP, which shows that the model group of rats is in a state of malnutrition, which is similar to the result of malnutrition caused by anorexia. The contents of serum BUN, ALT, AST and Cr increase, but are all in the normal value range. According to the search of acute influence data of erythromycin, the oral LD50 (half lethal dose) of rats is 4600mg / kg~9272mg / kg, and the modeling dose in the experiment is far less than the acute poisoning dose. Therefore, it can be excluded that the decrease of food intake of rats is caused by the possibility of organ damage due to too large a dose. In addition, the present application is different from other single-cage feeding modeling methods, and is changed to combined-cage feeding. Studies have confirmed that single-cage feeding is one of the preparation conditions of depression and other emotional disease models. Therefore, combined-cage feeding maximally reduces the possibility of emotional depression affecting food intake.

[0083] The present application verifies the treatment of the model rats by adopting the conventional method of "regulating the spleen and stomach, transporting the spleen and digesting food" through syndrome differentiation. The results show that the food intake of the treatment group of rats increases, the body weight increases, the feces gradually forms, the contents of serum ALB and TP increase, the contents of serum BUN, ALT, AST and Cr decrease, the microstructure of the gastric mucosa is towards recovery, and there are significant improvements in symptoms and signs and the microstructure of the stomach, which confirms that the pathogenesis of the pediatric anorexia model conforms to the TCM understanding of "spleen and stomach disorder and spleen dysfunction".

[0084] In summary, the pediatric anorexia animal model induced by the gradient increment gavage of erythromycin in the present experiment is highly similar to the clinical performance of pediatric anorexia in the macroscopic characterization of general signs, food intake and body weight changes, serum index detection and physiological and pathological microstructure of the stomach. The modeling method has strong operability, repeatability, and the dose is easy to control, which can provide a research model for pediatric anorexia and related research.

[0085] The above examples are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the above examples, and any changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principles of the present application should be equivalent replacement methods, and are all included in the protection scope of the present application.

Claims

1. A method for preparing an animal model of anorexia in children, characterized in that, The model is established by using erythromycin gradient increment gavage method; the specific method is as follows: starting from 0.04 g per animal, the animals are gavaged, and the basic dose is increased by 1 time every 3 days; when the food intake of the rats decreases by 20%~30% or the body weight is 10%~15% lower than that of the control group, the pediatric anorexia animal model is obtained; the control group is gavaged with distilled water.

2. The method for preparing a pediatric anorexia animal model according to claim 1, characterized in that, The animal is a rat.

3. The method for preparing a pediatric anorexia animal model according to claim 2, characterized in that, The rat is a male SPF SD rat.

4. The method for preparing a pediatric anorexia animal model according to claim 3, characterized in that, The male SPF SD rat is three weeks old, and the body weight is between 60~80 g.

5. The method for preparing a pediatric anorexia animal model according to any one of claims 1-4, characterized in that, All rats in the modeling group and the control group can freely obtain food and water, the room temperature is 25℃±0.5℃, and the relative humidity is 55%±5%.

6. The method for preparing an animal model of pediatric anorexia according to claim 1, characterized in that, Compared with the control group, the following indexes of the pediatric anorexia animal model have significant changes: The food intake decreases by 20%~30% or the body weight decreases by 10%~15%; The appetite decreases, the hair is rough, dull and lusterless, the rats are curled up and less active, and the stool is not formed or is loose; The contents of serum albumin (ALB) and protein quantification (TP) decrease, and the contents of urea nitrogen (BUN), alanine transaminase (ALT), aspartate aminotransferase (AST) and creatinine (Cr) slightly increase; A small amount of inflammatory factor infiltration, local congestion, and a small amount of epithelial cell erosion and shedding can be observed in the antral tissue, and the epithelial cells in the mucosa layer are arranged more disorderly than those in the blank group; And the above indexes still cannot recover to the normal level of the control group within two weeks after the modeling is completed, which meets the clinical characteristics of reduced appetite for a long period of time, that is, the modeling is successful.

7. The pediatric anorexia animal model according to any one of claims 1~6 is applied in the screening of related therapeutic drugs.

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