Preparation method and application of child anorexia animal model

Abstract

The invention discloses a preparation method and application of an infantile anorexia animal model, and belongs to the technical field of medicines. The model can be used for screening, pharmacological research and efficacy evaluation of medicines for treating child anorexia. A modeling method of erythromycin gradient increment intragastric administration is creatively adopted for the first time, and the child anorexia animal model is successfully established. Compared with a conventional high-fat and high-protein-fat feed feeding and central operation modeling mode, the modeling method has the following advantages that the modeling time is shortened, and the modeling time cost is reduced by two weeks compared with other modeling modes; compared with expensive high-fat and high-protein feed, the cost of erythromycin medicine is 1 / 10 of that of the high-fat and high-protein feed, and the time cost is shortened, so that the animal feeding cost is also reduced; the operation technology is simple and convenient; compared with preparation of a high-precision central anorexia animal model, the experiment operation technology is simple; the conditions for laboratory instruments and equipment are relatively low; the requirements of experimenters are reduced, and the labor cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the field of medical technology, and specifically relates to a preparation method and application of an animal model of "anorexia in children", a common childhood disease in traditional Chinese medicine. The model can be used for drug screening, pharmacological research, efficacy evaluation, and pathogenesis and pathological characteristics research of drugs for the treatment of anorexia in children. Background Art

[0002] In recent years, with the development of social economy and the change of lifestyle, the etiology and symptoms of anorexia in children have also shown new characteristics: in addition to the common causes of bad eating habits and long-term unreasonable diet structure (for example, overeating, craving for sweet and greasy food and various processed foods), changes in children's living environment, 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 anorexia in children, and can be seen with common pediatric psychological disorders such as attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), anxiety disorders, etc. The contemporary characteristics of the etiology and symptoms of anorexia in children put forward new requirements for the diagnosis and treatment of this disease in contemporary Chinese pediatrics, and strengthening the research on the mechanism and mechanism of anorexia and comorbidities in children and the research on the efficacy of treatment has become a new challenge.

[0003] At present, the preparation methods of animal models of pediatric anorexia are mainly divided into three categories: 1. Feeding young rats with a special high-protein and high-fat diet to establish a pediatric anorexia model: This is a modeling method that is used more frequently in pediatric anorexia models. This method was used to establish the model in the early stage of this model. We found that on the 14th, 21st and 28th days of feeding with a special diet, the model-prepared rats had a significantly lower food intake than the blank group; the body weight lagged slightly behind the change in food intake. However, when normal feed feeding was resumed on the 29th day and the persistence of anorexia symptoms was observed, it was found that the food intake of rats in the model-prepared group began to increase rapidly, and the statistically significant difference was quickly lost compared with the blank group (P>0.05), and the body weight also resumed the growth rate. The cause and mechanism of this phenomenon are still unclear, but it has become the starting point for our research group to develop a new method for preparing a pediatric anorexia model. 2. Animal model of spleen deficiency syndrome: A mouse spleen deficiency model was established by slowly administering reserpine in small doses. However, this drug modeling has been used in animal models of various diseases, and the symptoms and diseases presented in the end are different, so the preparation method of this model is still controversial. 3. Animal model of central anorexia: A cannula is pre-placed in the lateral ventricle of the animal to inject leptin, which is used as a model of central anorexia. This model is consistent with the pathogenesis of anorexia and provides a new idea for the study of anorexia. However, due to the high mortality rate of rats with intraventricular catheters and the complexity of experimental operations, the replication and application of this model are seldom. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of complicated operation and poor simulation effect of the existing animal model of anorexia in children, and to provide a preparation method and application of the animal model of anorexia in children.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing an animal model of pediatric anorexia, which uses a gradient incremental gavage method of erythromycin to establish a model; the specific method is as follows: starting from 0.04g / rat, gavage is performed on the animals, and the basic dose is increased by 1 time every 3 days; when the rats' food intake decreases by 20% to 30% compared with a control group or their body weight is 10% to 15% lower than that of the control group, an animal model of pediatric anorexia is obtained; the control group is gavaged with distilled water.

[0007] According to the state of the rats after taking the medicine, such as food intake, body weight, and feces changes. During the experiment, in two to three days, the rats will begin to recover their own defenses and need to increase their intake. Find the rules in the changes and pay close attention to the changes in food intake and body weight.

[0008] Generally, acute poisoning will not occur if the dosage limit is not exceeded. The data on acute effects of erythromycin show that the oral LD50 (median lethal dose) of rats is 4600mg / kg to 9272mg / kg. The dosage used in the study is small, but the shape of rat feces has changed. Considering that the rats are three weeks old and relatively light in weight, a large dose may be a short-term reaction. The gradient increment can effectively maintain the reaction of decreased appetite and gastrointestinal discomfort in rats. At the same time, the rats' converted age and two weeks simulate the symptoms of decreased appetite and gastrointestinal discomfort in children after long-term use of erythromycin.

[0009] Furthermore, the animal is a rat.

[0010] Furthermore, the rats are male SPF-grade SD rats.

[0011] Furthermore, the male SPF SD rats are three weeks old and weigh between 60 and 80 g.

[0012] Furthermore, all rats in the modeling group and the control group had free access to food and water, the room temperature was (25±0.5)°C, and the relative humidity was (55±5)%.

[0013] Furthermore, the following indicators of the pediatric anorexia animal model were significantly changed compared with the control group:

[0014] Food intake decreased by 20% to 30% or body weight decreased by 10% to 15%;

[0015] Decreased appetite, coarse, dull hair, curled up and less active, loose or unformed stools;

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

[0017] A small amount of inflammatory factor infiltration was observed in the gastric antrum tissue, local congestion, the arrangement of epithelial cells in the mucosal layer was more disordered than that in the blank group, and a small amount of epithelial cells fell off (eroded and fell off);

[0018] Moreover, the above indicators still could not return to the normal level of the control group within two weeks after the end of the modeling, which was consistent with the clinical characteristics of long-term anorexia, that is, the modeling was successful.

[0019] For example, the above-mentioned animal model of pediatric anorexia is used in the study of the pathogenesis of pediatric anorexia, the study of pathological characteristics, the screening of relevant therapeutic drugs, pharmacological research and efficacy evaluation.

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

[0021] The method of the present invention is simple and convenient to operate, can successfully establish an animal model of anorexia in children in a short time, does not require expensive instruments and equipment, does not require a large number of scientific research and development personnel, and is easy to reproduce; has good fitting and stability, and has a high fitting with clinical manifestations of anorexia in children (decreased food intake, body weight, overall state, serum protein observed by HE in gastric tissue, and index detection, and decreased protein), and can be fed with normal standard feed continuously during the modeling period. The present invention has a high experimental basis for the pathogenesis of anorexia in children, clinical diagnosis and treatment, and new drug development, and this modeling method is suitable for promotion and application.

[0022] The present invention has the following advantages over conventional high-fat and high-protein feed feeding and central anorexia surgery modeling methods: (1) Shortened modeling time: The modeling time cost is reduced by two weeks compared with other modeling methods; (2) Reduced economic cost: Compared with the more expensive high-fat and high-protein feed, the cost of erythromycin is 1 / 10 of that of the expensive high-fat and high-protein feed, and the shortened time cost also reduces the cost of animal feeding; (3) Simple and convenient operation technology: Compared with the preparation of a high-precision central anorexia animal model, the experimental operation technology is simple; the conditions for laboratory instruments and equipment are relatively low; the demand for experimental personnel is reduced, thereby reducing labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Figure 2 shows the shapes of rat feces in different groups.

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

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

[0026] Figure 4 This is a comparison chart of serum ALB and TP levels in rats of different groups.

[0027] Figure 5 The figure shows the pathological analysis and comparison of gastric mucosal lesions in rats of different groups (HE staining ×100 and ×200). DETAILED DESCRIPTION

[0028] The technical scheme of the present invention is described in detail below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited to the scope of the embodiments. The process parameters not specified in the embodiments of the present application can be carried out according to conventional methods, and the raw materials used can be obtained through commercial channels.

[0029] Example 1

[0030] 1 Materials

[0031] 1.1 Experimental animals

[0032] Twenty-four male SPF SD rats, three weeks old, with an average body weight of (60-80) g, were purchased from Sibeifu (Beijing) Biotechnology Co., Ltd. (License No. SCXK (Beijing) 2024-0001) and housed in cages (4 rats / cage). All rats had free access to food and water, room temperature (25±0.5)°C, relative humidity (55±5)%, and 12-h light-dark alternating lighting.

[0033] 1.2 Experimental drugs

[0034] Modeling drug: Erythromycin enteric-coated tablets (manufacturer: Xi'an Lijun Pharmaceutical Co., Ltd.; approval number: National Medicine Standard H61021632; specification: 0.125 g; batch number: 2301242040).

[0035] Treatment drugs: The ingredients of Yunpi Xiaoshi granules include Codonopsis pilosula, Atractylodes macrocephala, Atractylodes lancea, Poria cocos, dried tangerine peel, chicken gizzard lining, charred hawthorn, Shenqu, malt, yam, and white hyacinth bean. The granules are made into granules by the Traditional Chinese Medicine Prescription Preparation Room of Shanxi Provincial Hospital of Integrated Traditional Chinese and Western Medicine.

[0036] 1.3 Main Reagents

[0037] Albumin (ALB) assay kit, protein quantitative (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, catalog number: A028-2, A045-4, C013-2, C009-2, C010-2, C011-2); physiological saline, PBS solution (ASPEN, catalog number: AS1087, AS1044); eosin Y (alcohol soluble) (West Asia Reagent, catalog number: D12621); hematoxylin (Sigma, catalog number: H9627-25 G); paraformaldehyde, anhydrous ethanol, xylene, 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 water (Sinopharm Chemical Reagent Co., Ltd., catalog number: 80096618, 10009218, 10023418, 10019318, 20040718, 10020318, 10011018, 80117214, 10001060, 10007118, 10000218, 10002018); neutral gum (Solarbio, catalog number: G8590).

[0038] 1.4 Main instruments

[0039] ELISA reader (Molecular Corporation, 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 (Jintan Jiangnan Instrument Factory, model: HH-W-600); constant temperature incubator (Shanghai Jinghong Experimental Equipment Co., Ltd., model: GNP9160); ordinary optical microscope, inverted white light / fluorescence photography microscope, upright white light photography 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 counter-evidence group (n=8) according to the random number table method. The model group and the treatment group were given erythromycin by gavage, which was converted to 0.02 g / rat according to the body surface area method for an adult with a body weight of 60 kg, and the gavage was performed based on the 2-fold dose of 0.04 g / rat. The erythromycin enteric-coated tablets were ground into powder and dissolved in distilled water. The model was administered daily, but the dose was doubled every 3 days (i.e., 2, 3, 4, and 5 times of 0.04 g / rat). The gavage dose can be fine-tuned according to the food intake, body weight loss, and stool texture changes of the model group rats. For details, see Table 1. The blank group was given an equal volume of normal saline by gavage as a solvent control. The above rats were gavaged for a total of 14 days. The food intake of the rats was recorded 24 hours a day, the body weight was measured twice a week, and the hair, tail, stool texture, and emotional activity of the rats were closely monitored to see if they were excited or irritable. The model was successful when the rats' food intake decreased by an average of 20% to 30%, or when their body weight was 10% to 15% lower than that of the control group, which was consistent with the symptoms of anorexia in children in traditional Chinese medicine.

[0043] Table 1 Erythromycin model gavage dosage table

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

[0045] 2.2 Drug intervention (testing with prescription)

[0046] After the anorexia model was successfully established, the treatment group was given Yunpi Xiaoshi granules for intervention treatment. The gavage dose was converted to 6.4 g / kg·d according to the body surface area method for a 60 kg adult, and the gavage volume was 1 mL / 100 g. Rats in the blank group and model group were gavaged with normal saline as a control for 14 consecutive days.

[0047] 2.3 Specimen collection

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

[0049] 3 Main Observation Indexes

[0050] 3.1 General signs observation

[0051] Observe the general physical signs of the rats, such as the dullness of their hair and tail, their emotional state, the size and hardness of their feces particles.

[0052] 3.2 Monitoring of food intake and body weight

[0053] Weigh enough feed per cage at regular intervals every day, and weigh the remaining feed at a fixed time the next day. Calculate the rat's 24-hour food intake, 24-hour food intake = original amount - remaining amount. The average daily food intake of each rat is the food intake per cage divided by the number of rats 4. Weigh and record the body weight every Monday or Saturday morning.

[0054] 3.3ELISA method to detect the content of albumin (ALB), total protein (TP), urea nitrogen (BUN), alanine transferase (ALT), aspartate transferase (AST), and creatinine (Cr)

[0055] ELISA method was used to detect the levels of serum ALB, TP, BUN, ALT, AST, and Cr. The experimental tests were carried out strictly according to the instructions of the kit.

[0056] 3.4 Observation of pathological sections of gastric antrum tissue stained with HE

[0057] The gastric antrum and its surrounding area (1×1 cm) were obtained and routinely embedded in paraffin for sections. The sections were dewaxed, hydrated with ethanol gradient, the nuclei were stained with hematoxylin, the cytoplasm was stained with eosin, and the sections were gradiently dehydrated to make them transparent. After sealing with neutral gum, the tissue morphology was observed under an optical microscope.

[0058] 3.5 Statistical analysis

[0059] SPSS22.0 statistical software was used for statistical analysis. The measured data were expressed as (x±s). For data with normal distribution and equal variance, one-way analysis of variance was used for comparison among multiple groups, and LSD-t test was used for multiple comparisons between two groups. For data without normal distribution or equal variance, Kruskal-Wallis H test was used for comparison among multiple groups, and Mann-Whitney U test was used for comparison between two groups. P<0.05 was considered statistically significant. GraphPad Prism8 was used for drawing.

[0060] 4 Experimental results

[0061] 4.1 General signs observation

[0062] General physical sign observation showed that before modeling, rats in each group were in good condition and had no abnormal performance. On the 4th and 5th days after modeling, rats in the model group had reduced food intake, rough and loose hair, occasional irritability, and preferred to curl up; soft and loose stools with a slightly green-yellow color; after treatment with Yunpi Xiaoshi Granules, the hair became smooth and shiny, the reaction was sensitive, and the movement was free. The stools were brown, dry, and moderately hard and soft, tending to be normal (see Figure 1 ).

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

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

[0065] First, the success of the model establishment was evaluated by comparing the body weight and food intake of the rats during the modeling period. Figure 2 It can be seen that the food intake and body weight of rats in each group were in normal state before modeling. After modeling by oral administration of erythromycin, the food intake and body weight of rats in the model group and the treatment group showed a downward trend.

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

[0067] The second week of modeling (modeling period II): the food intake and body weight of rats in the model group and the treatment group began to decrease rapidly, and there were significant differences compared with the blank group, which were statistically significant (P<0.01). The food intake was lower than 24.0%-25.7%, and the body weight was lower than 8.0%-10.4%. There was no rebound in a short period of time (10-14 days), which met the requirements for the preparation of the pediatric anorexia model.

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

[0069] At the beginning of the intervention treatment with Yunpi Xiaoshi Granules (treatment period Ⅰ), compared with the blank group, the food intake and body weight of the model group still maintained a significant downward trend (P<0.01); compared with the model group, the food intake of the Yunpi Xiaoshi Granule treatment group increased (P<0.05), but the increase in body weight was relatively slow. After the second week of intervention treatment (treatment period Ⅱ), compared with the blank group, the food intake and body weight of the model group continued to decrease (P<0.01); compared with the model group, the food intake of the treatment group increased significantly (P<0.01), and the body weight increased synchronously, as shown in Table 2. Figure 3 .

[0070] 4.3 Results of relevant serum index tests

[0071] 4.3.1 Comparison of serum ALB and TP levels

[0072] Compared with the blank group, the levels of serum ALB and TP in the model group were significantly decreased (**P<0.01; *P<0.05). After treatment with Yunpi Xiaoshi granules, the levels of serum ALB and TP in the treatment group were significantly increased ( # P < 0.05), see Figure 4 .

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

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

[0075] Table 2 Comparison of ALT, AST, BUN and Cr levels in rat serum (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 Pathological observation of gastric antrum

[0079] In the model group, a small amount of inflammatory factors infiltration was observed in the gastric antrum tissue of rats. The arrangement of epithelial cells in the mucosal layer was disordered compared with that in the blank group, and some epithelial cells eroded and fell off. In the treatment group, the pathological changes of gastric antrum tissue of rats were significantly improved, the structure was gradually complete, the glands increased and became full, and the inflammatory infiltration decreased. Figure 5 .

[0080] Based on the background status and the failure of modeling with high-protein and high-fat feed in the early stage, the present invention considers using appropriate drugs to prepare the model. After screening, erythromycin became the first choice of model preparation drug due to its obvious gastrointestinal reaction and high toxicity threshold.

[0081] As an agonist of motilin receptor (MTLR), erythromycin simulates exogenous motilin in gastrointestinal contractile activity and directly stimulates gastrointestinal motility: low concentrations of erythromycin can promote cholinergic activity to increase gastrointestinal motility, while higher concentrations can stimulate cholinergic function and directly contract muscles, inducing prolonged and non-propulsive hypermotility of the gastric antrum by contracting the gastric fundus, causing nausea and other discomfort symptoms. Secondly, erythromycin is also a representative drug of macrolide antibiotics. Because of its spectrum activity, while fighting pathogens, it also targets symbiotic bacteria in the body, causing a sharp decline in the dominant intestinal bacteria Bacteroides, disrupting the composition of intestinal microbiota, causing dysbiosis, and causing many gastrointestinal reactions. Therefore, the loss of appetite or aversion to eating caused by erythromycin is related to its dose. The gradient increment of erythromycin can highly simulate the characteristics of a long period of reduced food intake in young rats, which is consistent with the above research conclusions, and at the same time overcomes the phenomenon of gastrointestinal adaptability and food intake recovery in rats to daily equal dose administration.

[0082] After the model was established, the liver and kidney function of the rat serum was tested. Serum ALB and TP are important indicators for reflecting the nutritional level of children. Once protein-energy deficiency occurs, it will drop rapidly. When protein energy intake increases, it can rebound significantly in 3 days. Therefore, it can quickly reflect whether the nutritional intake is in positive balance or negative balance, and can be used as an indicator to quickly reflect the nutritional status. Figure 4 , the reduction of food intake and body weight of rats in the model preparation group was accompanied by a decrease in serum ALB and TP, which indicated that the rats in the model group were in a state of malnutrition, similar to the result of malnutrition caused by anorexia. Although the serum BUN, ALT, AST, and Cr contents increased, they were all within the normal range. The data on the acute effects of erythromycin were retrieved and showed that the oral LD50 (median lethal dose) of rats = 4600mg / kg ~ 9272mg / kg, and the modeling dose during the experiment was much smaller than the acute poisoning dose. Therefore, the possibility that the reduction in rat food intake was due to organ damage caused by excessive drug dosage can be ruled out. In addition, the present invention is different from other single-cage modeling methods and is changed to co-cage breeding. Studies have confirmed that single-cage breeding is one of the preparation conditions for emotional disease models such as depression. Therefore, co-cage breeding minimizes the possibility that emotional depression affects food intake.

[0083] The present invention uses the conventional "harmony of spleen and stomach, spleen and digestion" method to verify the treatment of model rats. The results show that the rats in the treatment group have increased food intake, body weight, and gradually formed feces, increased serum ALB and TP levels, decreased serum BUN, ALT, AST, and Cr levels, and the microstructure of the gastric mucosa has improved. There are significant improvements in symptoms and signs and the microstructure of the stomach, which confirms that the pathogenesis of the pediatric anorexia model is consistent with the traditional Chinese medicine understanding of "spleen and stomach disorders and spleen dysfunction".

[0084] In summary, the animal model of pediatric anorexia induced by erythromycin gradient-increment gavage established in this experiment is highly similar to the clinical manifestations of pediatric anorexia in terms of general signs of rats, macroscopic manifestations of changes in food intake and body weight, serum index detection, and physiological and pathological microstructure of gastric tissue. This modeling method has strong operability and repeatability, and the dosage is accurate and easy to control, which can provide a research model for pediatric anorexia and related studies.

[0085] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

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

2. The method for preparing an animal model of anorexia in children according to claim 1, characterized in that: The animals are rats.

3. The method for preparing an animal model of anorexia in children according to claim 2, characterized in that: The rats are male SPF grade SD rats.

4. The method for preparing an animal model of anorexia in children according to claim 3, characterized in that: The male SPF SD rats were three weeks old and weighed between 60 and 80 g.

5. The method for preparing an animal model of anorexia in children according to any one of claims 1 to 4, characterized in that: All rats in the modeling group and the control group had free access to food and water, and the room temperature was (25±0.5)°C and the relative humidity was (55±5)%.

6. The method for preparing an animal model of anorexia in children according to claim 1, characterized in that: Compared with the control group, the following indicators of the pediatric anorexia animal model showed significant changes: Food intake decreased by 20% to 30% or body weight decreased by 10% to 15%; Decreased appetite, coarse, dull hair, curled up and less active, loose or unformed stools; The levels of albumin (ALB) and protein (TP) in serum decreased, and the levels of blood urea nitrogen (BUN), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatinine (Cr) increased slightly; A small amount of inflammatory factor infiltration was observed in the gastric antrum tissue, local congestion, the arrangement of epithelial cells in the mucosal layer was more disordered than that in the blank group, and a small amount of epithelial cells fell off (eroded and fell off); Moreover, the above indicators still could not return to the normal level of the control group within two weeks after the end of the modeling, which was consistent with the clinical characteristics of long-term anorexia, that is, the modeling was successful.

7. Use of the animal model of anorexia in children as claimed in any one of claims 1 to 6 in the study of the pathogenesis of anorexia in children, the study of pathological characteristics, the screening of relevant therapeutic drugs, pharmacological research and the evaluation of drug efficacy.

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