General anesthetics used for laboratory animals are mostly controlled drugs, and are subject to strict supervision by the competent government agency in China. Many general anesthetics recommended in the literature are either unavailable or difficult to procure/access in the market, resulting in limited options for clinical use. Furthermore, not all laboratory veterinarians have practical experience in species-specific anesthetic selection and use. Owing to these factors, general anesthesia presents a common institutional challenge in animal surgical programs and serves as a bottleneck that restricts the sustainable development of biomedical industries working with laboratory animal species. This article summarizes the pharmacological properties of common general anesthetics and provides suggestions for general anesthesia in different laboratory animal species.

Renal interstitial fibrosis is a common pathway in the progression of many renal diseases. Whether it is chronic kidney disease or acute kidney injury that cannot be fully recovered, the progression process mostly enters end-stage renal failure after renal interstitial fibrosis. The animal model of renal interstitial fibrosis is an important research tool for exploring the pathogenesis of renal interstitial fibrosis and new diagnostic and treatment methods. Different animal models have their own characteristics. Researchers can establish different models based on their own experience and experimental purposes, and carry out scientific research on this basis to provide more new methods for the prevention and treatment of kidney diseases. The authors focused on several common animal models of renal interstitial fibrosis to provide the reference for related researchers, including surgical models induced by unilateral ureteral obstruction, ischemia-reperfusion injury, 5/6 nephrectomy, and microembolization; chemical models induced by cyclosporine A, adriamycin, aristolochic acid, mercuric chloride（HgCl₂）, gentamicin, cisplatin, and adenine; transgenic hybridization and kidney injury molecule 1 (KIM-1) induced transgenic modification model; composite model induced by bilateral ischemia-reperfusion injury (BIRI) combined with gentamicin, unilateral nephrectomy combined with angiotensin II (Ang II), and unilateral ischemia-reperfusion injury (UIRI) combined with pLVX-shTNC plasmid.

Schizophrenia (SCZ) is a highly destructive and complex psychiatric disorder illness, accompanied by a variety of positive and negative symptoms along with cognitive impairment, which brings a heavy social burden. Elucidation of the pathogenesis and therapeutic development is challenging because the complex interplay between genetic risk factors and environmental factors in essential neurodevelopmental processes. Therefore, preparing appropriate animal models can help people better understanding the neurobiological basis of SCZ and provide theoretical basis for finding new treatments. In order to provide reference for the application and improvement of SCZ animal models, this commentary reviewed several main modeling methods for animal models of SCZ, including neurodevelopmental models, drug-induced animal models, and genetic models, and the behavioral evaluation, histological analysis and possible molecular mechanisms of SCZ animal models were also outlined.

Hernia is a common and frequently occurring condition in general surgery, referring to the displacement of an organ or part of an organ from its normal anatomical position through a congenital or acquired weak point, defect, or space into another area. Its pathogenesis is complex, involving multiple factors such as abdominal wall weakness or increased intra-abdominal pressure. The clinical manifestations of hernia vary depending on its type, location, and severity. As the aging of the population continues to advance, the incidence of hernia has been increasing annually. Animal models serve as an important tool in hernia research. They enable the evaluation of the safety and efficacy of new repair materials and techniques, as well as assisting clinicians in developing new surgical methods and investigating the mechanisms and novel therapies for certain hernia diseases and their complications. Given the significant differences in the pathophysiological mechanisms of different types of hernia diseases, the methods and evaluation criteria for establishing animal models are highly diverse. Furthermore, the methods for establishing animal models are closely related to experimental objectives, and different experimental goals require different animal models. Therefore, selecting appropriate animal models based on experimental objectives is crucial for ensuring the smooth progress of research and obtaining reliable results. To this end, this review summarizes effective methods for establishing animal models for external abdominal hernias (including incisional hernia, inguinal hernia, umbilical hernia, parastomal hernia, incarcerated hernia, and pelvic floor hernia), congenital diaphragmatic hernia, hiatal hernia, and cerebral hernia. It provides a detailed analysis of the advantages, disadvantages, and evaluation criteria of these models. Additionally, this review summarizes recent preclinical applications of new hernia repair materials, aiming to provide references for animal experimental research in the field of hernia studies.

The host digestive tract comprises trillions of commensal microbes, collectively called microbiota. These microbes interact with a various host cell types and have a significant impact on health and disease. High-throughput sequencing technologies have accelerated the identification of numerous poorly studied microbes associated with health and disease. Genetic and humanized mouse models with and without environmental exposure were established to study the roles of these microbes in human physiologies and pathologies. Important findings related to the microbiota, mucosal immunity, and infectious diseases in mouse models are summarized. Furthermore, challenges and opportunities in leveraging genetic approaches and environmental exposure to optimize mouse models are discussed.

The occurrence of intrauterine growth restriction (IUGR) may be related to maternal malnutrition, abnormal placental function, immune abnormalities, genetically related problems as well as other diseases, but the mechanism is still unclear. Therefore, the study of IUGR and the development of its animal model are critical issues in obstetrics. IUGR models are mainly based on laboratory rodents, such as mice and rats, and other mammals such as pigs, rabbits and sheep. This article introduced several common IUGR animal models, including nutrition restriction model, high-altitude pregnancy model, natural selection model, and nicotine exposure model, and also described the construction methods of IUGR models and the comparison of their advantages and disadvantages.

Ischemic stroke refers to the ischemic necrosis or softening of limited brain tissue caused by cerebral blood circulation disorder, ischemia and hypoxia, resulting in corresponding neurological functional defects. Ischemic stroke is one of the primary causes of human disability, seriously threatens human health, and there is still no effective treatment by now. In order to study the pathogenesis of ischemic stroke and prevent and treat it better, it is very important to establish appropriate animal models.This paper aims to summarize the animal models of ischemic stroke and its advantages and disadvantages.

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases, which seriously affects the health of the elderly people. The drugs currently approved for the treatment of AD can only reduce the symptoms severity of AD, but can't cure AD or prevent the deterioration of AD. Over the past 40 years, there have been numerous treatments for AD, including compounds that prevent amyloid deposition in the brain or remove existing amyloid plaques, but their clinical curative effects are not significant. Therefore, more basic and clinical studies are needed to improve our understanding of the biological mechanism of AD. Experimental animal models are very important not only for the study of the pathogenesis of AD, but also for the development of AD drugs. This paper reviewed the main histopathological characteristics, genetic factors, the current animal models and model evaluation of AD.

Improving the reproducibility of biomedical research results is a major challenge.Researchers reporting their research process transparently and accurately can help readers evaluate the reliability of the research results and further explore the experiment by repeating it or building upon its findings. The ARRIVE 2.0 guidelines, released in 2019 by the UK National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), provide a checklist applicable to any in vivo animal research report. These guidelines aim to improve the standardization of experimental design, implementation, and reporting, as well as the reliability, repeatability, and clinical translatability of animal experimental results. The use of ARRIVE 2.0 guidelines not only enriches the details of animal experimental research reports, ensuring that information on animal experimental results is fully evaluated and utilized, but also enables readers to understand the content expressed by the author accurately and clearly, promoting the transparency and integrity of the fundamental research review process. At present, the ARRIVE 2.0 guidelines have been widely adopted by international biomedical journals. This article is a Chinese translation based on the best practices of international journals following the ARRIVE 2.0 guidelines in international journals, specifically for the complete interpretation of the ARRIVE 2.0 guidelines published in the PLoS Biology journal in 2020 (original text can be found at https://arriveguidelines.org). The third part of the article includes the items 8-10 of ARRIVE 2.0 Essential 10, which covers "experimental animals" "experimental procedures" and "results". Its aim is to promote the full understanding and use of the ARRIVE 2.0 guidelines by domestic researchers, enhance the standardization of experimental animal research and reporting, and promote the high-quality development of experimental animal technology and comparative medicine research in China.

Ulcerative colitis (UC) is a chronic, idiopathic inflammatory bowel disease. Its pathogenesis has not been fully revealed. Moreover, the lack of effective and safe treatment strategies is an obstacle for UC treatment currently. Animal models are essential tools in disease research. Therefore, the establishment of animal models with pathological manifestations similar to human UC is conducive to the full study of this disease. In this review, we reviewed the research progress of animal models of UC, and found that chemical induction is the most commonly used method for modeling UC. Based on the development of genomics technology, gene editing or knockout-induced spontaneous colitis is a vital direction for animal models research in the future. In addition, the indexes for evaluating the modeling results of UC animal models need to be further explored.

Objective To study the efficacy of DZ1462, a novel sodium-phosphate transporter inhibitor, on rat hyperphosphatemia models established by 5/6 nephrectomy.Methods Totally 156 rats were randomly selected into four groups. Rats fed a normal diet were control group, named as group Ⅰ (n=6); rats fed a normal diet after 5/6 nephrectomy were named as group Ⅱ (n=60); rats fed a high phosphate diet after 5/6 nephrectomy were named as group Ⅲ (n=60); rats fed a high phosphate diet after sham surgery were named as group Ⅳ (n=30). The molding cycle was 10 weeks. Serum Pi was detected and the number of animal deaths was recorded every two weeks. Hematoxylin-eosin (HE) staining was performed to observe the change in kidney pathology, and to screen animal models with high phosphorus blood syndrome. Totally 18 model rats that met the inclusion criteria (all of group Ⅲ) were selected and randomly assigned to three groups: the model control group recorded as the G2 group; the DZ1462 administration group (30 mg/kg, tid, 21 d) recorded as the G3 group; the Sevelamer administration group (250 mg/kg, tid, 21 d) recorded as the G4 group. In addition, the normal control group was set as the G1 group. Serum phosphate levels were measured using a kit.Results In the 8^th and 10^th weeks, compared to group Ⅰ, serum phosphorus in group Ⅲ showed a significant difference (P < 0.01). The kidneys in group Ⅲ had obvious glomerular sclerosis, renal tubular atrophy, degeneration, interstitial inflammation, fibrosis, and calcification. Similarly to chronic kidney disease accompanied by hyperphosphatemia, the animal model was established successfully. At each time point, the serum phosphorus inhibition rate of the G3 group was significantly higher than that of the G4 group (P < 0.05).Conclusion DZ1462, as a novel small-molecule inhibitor of intestinal sodium and phosphorus transporter, can effectively inhibit intestinal phosphorus ion absorption in rat hyperphosphatemia model, and is expected to become a potential drug for the clinical treatment of hyperphosphatemia.

Bronchial asthma (hereinafter referred to as asthma) is a common chronic respiratory disease characterized by airway inflammation, airway hyperresponsiveness, and airway remodeling. Its pathogenesis is highly complex and heterogeneous, involving multiple factors such as genetics, immunity, and environmental exposure. Currently, therapeutic options for asthma remain relatively limited, making it an urgent priority to explore its underlying mechanisms, identify effective treatment strategies, and develop new drugs. In this context, the establishment of animal models for asthma plays an irreplaceable and crucial role. However, to date, no single ideal animal model has been able to fully and accurately replicate all the features of the onset and progression of human asthma. This study systematically reviews the research progress over the past five years in the establishment methods of asthma animal models. It provides a detailed overview of commonly used experimental animals (such as mice, rats, and guinea pigs), frequently used sensitizing agents (including ovalbumin, house dust mite, lipopolysaccharide, and toluene diisocyanate), and the methods for establishing asthma models using these animals and sensitizers. This study also presents an objective evaluation of the advantages, limitations, and applicability of each model. Evaluation criteria for asthma models are summarized across multiple dimensions, including behavioral assessments, pulmonary function, histopathology, immunological indicators, and pharmacodynamics. Although methods for establishing refractory asthma models remain underdeveloped, several strategies for modeling refractory asthma have been summarized through a review of relevant literature, aiming to provide useful references for related research. Based on current scientific and technological advancements, it is anticipated that future research on asthma animal models will focus more on clinical relevance, technological innovation, and multidisciplinary integration. Specifically, future models are expected to adopt multi-sensitizer induction protocols, apply cutting-edge tools such as gene editing, enhance clinical relevance and promote diversification and personalization of models. Furthermore, advanced technologies such as bioimaging and biosensing are anticipated to enable dynamic monitoring of airway inflammation and remodeling. Organ-on-a-chip platforms may also be explored as potential alternatives to traditional animal models. The ultimate goal is to develop multifactorial, composite models that better simulate the complexity and heterogeneity of human asthma.

Neuroblastoma (NB) is one of the most common malignant solid tumors in children, ranks fourth in the incidence of pediatric tumors, and accounts for 15% of pediatric tumor deaths in children in China. Despite the development of new treatment options, the prognosis for high-risk patients is still poor. An animal model that can replicate the tumorigenesis of NB is an important tool for the prevention and treatment of NB. However, there are currently no animal models that can simulate all features of human NB. To provide a reference for the construction of animal models and treatment of NB, this article introduced several animal models of NB that have been extensively researched: the mouse, chick embryo chorioallantoic membrane, and zebrafish models. At the same time, it elaborated on the species, construction methods, characteristics, advantages and disadvantages, and research progress in NB.

Improving the reproducibility of biomedical research results is a major challenge. Researchers reporting their research process transparently and accurately can help readers evaluate the reliability of the research results and further explore the experiment by repeating it or building upon its findings. The ARRIVE 2.0 guidelines, released in 2019 by the UK National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), provide a checklist applicable to any in vivo animal research report. These guidelines aim to improve the standardization of experimental design, implementation, and reporting, as well as the reliability, repeatability, and clinical translatability of animal experimental results. The use of ARRIVE 2.0 guidelines not only enriches the details of animal experimental research reports, ensuring that information on animal experimental results is fully evaluated and utilized, but also enables readers to understand the content expressed by the author accurately and clearly, promoting the transparency and integrity of the fundamental research review process. At present, the ARRIVE 2.0 guidelines have been widely adopted by international biomedical journals. this article is a Chinese translation based on the best practices of international journals following the ARRIVE 2.0 guidelines in international journals, specifically for the complete interpretation of the ARRIVE 2.0 guidelines published in the PLoS Biology journal in 2020 (original text can be found at https://arriveguidelines.org). The first part of the article includes the preface and the "Key 10" section, which covers "study design" "sample size" and "inclusion and exclusion criteria". Its aim is to promote the full understanding and use of the ARRIVE 2.0 guidelines by domestic researchers, enhance the standardization of experimental animal research and reporting, and promote the high-quality development of experimental animal technology and comparative medicine research in China.

With the increasing severity of global aging, aging-related issues have become the hotspot in the field of health. In recent years, animal aging models have been widely developed and applied, which is of great significance in the study of aging mechanism. Animals with short life span, such as Caenorhabditis Elegans and Drosophila Melanogaster, have natural advantages in the study of aging. Various rat and mouse aging models have been used in aging studies. In recent years, new animal aging models have been developed, such as the African turquoise killifish. The authors reviewed main animal models used in the study of aging, and analyzed the establishment methods, evaluation indexes, advantages and disadvantages of each model in order to provide reference for related research.

Objective To compare the effects and characteristics of cigarette smoke exposure (CSE) alone and CSE combined with airway instillation of bacterial lipopolysaccharide (LPS) in chronic obstructive pulmonary disease (COPD).Methods Male SD rats were randomly divided into control, CSE, and CSE+LPS groups, with 10 rats in each group. After 24 weeks, the models were established and the lung function of the rats was measured. Hematoxylin-eosin (HE) staining was performed to observe the pathological changes in the airway and lung tissue. The ELISA method was used to detect the level of serum interleukin-8 (IL-8) and tumor necrosis factor α (TNF-α) in peripheral blood.Results Airway resistance (RI), functional residual capacity (FRC), and chord compliance (Cchord) of the CSE and LPS+CSE groups were higher than those of the control group (all P < 0.05), while the tidal volume (TV), minute volume (MV), and forced expiratory volume in 50 ms (FEV50) / forced vital capacity (FVC) of the CSE and LPS+CSE groups were lower than those of the control group (all P < 0.05). HE staining of lung tissue showed that the average alveolar intercept and thickness of the small airway walls were higher in the CSE and LPS+CSE groups than those in the control group. Compensatory enlargement was evident in the alveolar cavity of the CSE and CSE+LPS groups, and the alveolar septum widened, with a fusion of pulmonary alveoli in the CSE+LPS group. The levels of IL-8 and TNF-α in serum of the CSE and CSE+LPS groups were higher than those of the control group (all P < 0.05). The level of TNF-α in serum of the CSE+LPS group was higher than that of the CSE group (P < 0.05).Conclusion The CSE combined with LPS method is superior to CSE alone for establishing the COPD rat model, and the combined model is closer to clinical manifestations.

Allergic contact dermatitis is a type Ⅳ hypersensitivity reaction caused by repeated skin exposure to a substance and is a common public health problem. Traditional skin sensitization tests are based on animal experiments such as guinea pig maximum test and closed patch. In recent years, with the increasing attention of animal ethics and the development of science and technology, alternative methods of skin sensitization test have emerged. According to different principles, these alternative methods are divided into in vivo alternative methods, several in vitro alternative methods based on harmful outcome pathways, and genomic allergen rapid test, etc. In this paper, we reviewed the progress of these alternative methods of skin sensitization test, and several integrated testing and evaluation methods based on adverse outcome pathways.

Objective To study the effect of Xiaoyusan new formula on the articular cartilage of knee osteoarthritis (KOA) rabbits and its mechanism. Methods A total of 42 New Zealand white rabbits aged 6 months were randomly divided into normal group, model group, ointment of Xiaoyusan group, and ointment of Xiaoyusan new formula group, with 10 rabbits in each group (the other 2 rabbits were used for model validation). Except for the normal group, the right knee joints of all rabbits in the other groups were prepared as KOA models according to the modified Hulth method. After 5 weeks of molding, the rabbits in ointment of Xiaoyusan group, ointment of Xiaoyusan New Formula group were given corresponding ointments for knee arthritis treatment, once a day, each time for 10 hours. After 2-week continuous administration and treatment, the knee joint cartilage of the four groups of rabbits was taken and the cartilage damage of each group was evaluated by Outerbridge grading method. The pathological changes of the cartilage, calcified layer and subchondral bone of the knee joint of rabbits in each group were observed by HE staining method under the light microscope, and the degree of cartilage degeneration was evaluated by Mankin's method. The expression of matrix metalloproteinase-13 (MMP-13) in the cartilage of rabbit knee joint in each group was deteced by immunohistochemistry. Results After the general observation of articular cartilage, the Outerbridge grading showed that the number of high-grade animals in ointment of Xiaoyusan group was reduced compared with the model group (P<0.05), and the number of high-grade animals in ointment of Xiaoyusan new formula group was also reduced (P<0.05) compared with ointment of Xiaoyusan group. HE staining showed that Mankin's scores of articular cartilage in the four groups ranked from high to low: model group (10.82±1.76), ointment of Xiaoyusan group (6.19±1.23), ointment of Xiaoyusan new formula group (2.64±1.18) and normal group (0.28±0.17). The difference among four groups was statistically significant (P<0.05). Immunohistochemical detection showed that the positive rates of MMP-13 expression in rabbit articular cartilage tissues in each group were (67.90±13.94)% of model group, (37.10±19.16)% of ointment of Xiaoyusan group, (13.60±3.10)% of ointment of Xiaoyusan new formula group and (3.20±2.39) % of normal group, ranking from high to low, and the difference among four groups was statistically significant (P<0.05). Conclusion Xiaoyusan new formula can repair articular cartilage degeneration in KOA rabbits and decrease the expression of MMP-13 in cartilage, which may be one of the mechanisms of the treatment.

Improving the reproducibility of biomedical research results remains a major challenge. Transparent and accurate reporting of progress can help readers evaluate the reliability of research results and further explore an experiment by repeating or building upon its findings. The ARRIVE 2.0 guidelines, released in 2019 by the UK National Centre for the Replacement, Refinement, and Reduction of Animals in Research (NC3Rs), provide a checklist applicable to any in vivo animal research report. These guidelines aim to improve the standardization of experimental design, implementation, and reporting, as well as the reliability, repeatability, and clinical translatability of animal experimental results. The use of the ARRIVE 2.0 guidelines not only enriches the details of animal experimental research reports, ensuring that information on animal experimental results is fully evaluated and utilized, but also enables readers to understand the content expressed by the author accurately and clearly, promoting the transparency and integrity of the fundamental research review process. At present, the ARRIVE 2.0 guidelines have been widely adopted by international biomedical journals. This article is the second part of the Chinese translation of the complete interpretation of the ARRIVE 2.0 guidelines published in PLoS Biology in 2020 (original text can be found at https://arriveguidelines.org) and based on the best practices for following the ARRIVE 2.0 guidelines in international journals. This part includes Items 4-7 of "ARRIVE Essential 10" in the ARRIVE 2.0 guidelines: "Randomization", "Blinding", "Outcome Measurement", and "Statistical Methods". Our Chinese translated version aims to promote the full understanding and use of the ARRIVE 2.0 guidelines by domestic researchers, enhancing the standardization of experimental animal research and reporting, and promoting the high-quality development of experimental animal technology and comparative medicine research in China.

Gastric ulcer (GU) is one of the common, frequently-occurring and intractable diseases of the digestive system. Spleen-stomach deficiency cold type is the most common and hard-to-cure syndrome pattern of GU, and is both a focus and a challenge in medical research. Therefore, constructing a scientific, reasonable, and clinically practical animal model of GU with spleen-stomach deficiency cold type and formulating objective and effective evaluation criteria are of great significance for in-depth research on the pathogenesis and treatment of GU. In this paper, the methods for constructing GU animal models of spleen-stomach deficiency cold type are comprehensively introduced by systematically reviewing the relevant literature. Firstly, the construction methods of pathological models of GU in Western medicine are introduced, including pyloric ligation method, water immersion-restraint stress method, ethanol-induced method, acetic acid-induced method, etc. This paper expounds the establishment methods for spleen-stomach deficiency cold syndrome type model in traditional Chinese medicine (TCM), including diet disorder method, bitter cold diarrhea method, excessive fatigue method, Qi consumption and Qi impairment method, and overeating sour-flavor method. This paper focuses on the construction methods for disease-syndrome combination GU models of spleen-stomach deficiency cold type, including two-factor modeling method and three-factor modeling method. Meanwhile, the evaluation indices of GU animal models of spleen-stomach deficiency cold type were summarized from various aspects, including animal physical signs ( appearance symptoms, animal behavior, and metabolic indices), as well as tissue morphology and molecular biology-related indicators ( gastric function, oxidative stress, inflammatory factors, other cytokines, four coagulation parameters, intestinal flora detection ), for constructing a comprehensive evaluation system. From the perspective of prescription-based verification, this paper further analyzes the drug composition and pharmacological effects to infer the syndrome type of the treated animal model, so as to verify whether the target animal model is successfully constructed. This review aims to provide a valuable reference for establishing a syndrome-specific GU animal model that closely aligns with clinical reality and embodies the principles of Chinese medicine. This will further advance research on TCM-pattern GU syndromes and deepen the exploration of herbal medicine-based treatments for GU, ultimately promoting the clinical integration and advancement of Chinese medicine in GU therapy.

According to understanding of the pathogenesis of acne, scholars have established animal models of acne inflammation, animal models of grafting human skin acne, and natural acne animal models. The acne inflammation model is mainly induced by bacterial infection, chemical drug application, and foreign matter injection. Natural acne animal models include animals that some are sensitivity to hormones and some have clinical symptoms of acne. It is necessary to select appropriate model animals and replicate model methods for the development of acne intervention products with different degrees and mechanisms. At present, there are only human evaluation standards of acne health functions in China, but no animal evaluation standards, which has affected the in-depth study of the pathogenesis of acne as well as the research and development progress of acne products. This article summarizes the conditions for the occurrence of acne, the characteristics of human skin, the bidirectional effect of Cutibacterium acnes on human skin, acne animal models, and commonly used observation and evaluation indicators, providing the reference for studying the pathogenesis of acne, promoting acne treatment and health care, and developing treatment products.

Inflammatory bowel disease (IBD) is a chronic, relapsing intestinal disorder driven by multiple factors including genetics, immunity, and environment, and is clinically classified into ulcerative colitis and Crohn's disease. Currently, mice and zebrafish are the primary experimental animals used in IBD research, among which zebrafish have emerged as an ideal model due to their unique advantages. Compared with rodent models, zebrafish serve as an effective and convenient model, offering advantages such as a short life cycle, robust reproductive capacity, small size, and transparent embryos. These characteristics make zebrafish highly suitable for dynamic tracking of continuous pathological progression and high-throughput drug screening. Zebrafish share over 70% genetic homology with humans, and their intestinal cellular composition and ontogeny closely resemble those of humans. Moreover, the structure and characteristics of their gut microbiota are similar to the human intestinal microbiome, providing a solid foundation for studying the relationship between gut microbiota and IBD. With advances in biotechnology, zebrafish IBD models generated by chemical induction or genetic engineering can accurately simulate the core pathological features of human IBD, such as intestinal wall thickening, inflammatory cell infiltration, and elevated expression of pro-inflammatory factors. These models have played a significant role in revealing the pathogenesis of IBD as well as the development of targeted therapeutic drugs. This article first outlines the intestinal characteristics of zebrafish and features of zebrafish IBD models, then provides an in-depth analysis of their application in IBD pathogenesis research from multiple aspects, including genetics, immunity, environment and diet, and infection. It also reviews research progress on the application of zebrafish in the development of anti-inflammatory drugs, probiotics, and traditional Chinese medicine therapies, aiming to provide researchers with references for the rational use of zebrafish models at all stages of preclinical research, to advance fundamental IBD research and accelerate breakthroughs in this field.

Sepsis is a common acute and critical illness, and its pathogenic mechanism is complex, often involving multiple organs and systems in the body. Various factors such as inflammatory response, immune dysfunction, and coagulation dysfunction are connected into an interconnected and mutually influencing network system, aggravating the severity of the disease. At present, the case fatality rate of sepsis is about 25%, which is a serious threat to human health. Establishing a stable and reliable experimental animal model of sepsis is an important means to understand the mechanism of host defense regulation in the early stage of infection, the mechanism of host response disorder in the stage of disease progression and to study the therapeutic effect of new therapeutic drugs. At present, there are many methods to establish animal models of sepsis, and there are many influencing factors. Therefore, this paper reviewed the preparation methods and influencing factors of animal models of sepsis, in order to provide some references for researchers to select suitable animal models.

Laboratory animals are the foundational conditions and indispensable technical support in life science research and biomedical industry development. The scientific development of animal models of diseases is of great significance to biomedical research and industrial development. In light of the booming development of multiple emerging in vitro modelling technologies over the past decade, in 2022, the U.S. Senate unanimously passed the bill FDA Modernization Act 2.0. This bill rescinded the requirement for animal testing in investigating the safety and effectiveness of a drug—a federal mandate since 1938, and highlighted the potential of various invitro disease modeling approaches in future biomedical fields. This paper provides a comprehensive review of the latest advances and applications of in vitro disease modeling approaches in academia and industry followed by an interpretation of the FDA bill, namely cell culture, organoid, organ-on-a-chip, 3D bio-printing model and computer-based model. The paper next introduces the crossed applications of various disease models and discusses the advantages and disadvantages of each system, thereby providing insights into future trends in the use of animal disease models in China.

Biosafety is an important part of national security, and effective control of biological hazards of laboratory animals is the basis of using laboratory animals. Based on the experience of biosafety management in the Laboratory Animal Center of Shanghai General Hospital, this paper analyzed the potential biosafety threats faced by laboratory animal barrier facilities in the process of ensuring the smooth conducting of animal experiments from the perspective of a laboratory animal facility manager, and discussed the relevant countermeasures to reduce such risks, in order to provide a reference for the proper control of biosafety problems in animal experiments.

Laboratory animals serve as the cornerstone in life science research, acting as surrogate models for human physiology, pathology, and disease treatment. They play an irreplaceable role in basic research, drug development, and translational medicine. Gut microbiota, a complex microbial community comprising bacteria, fungi, viruses, and unicellular organisms, colonizes the host's intestinal tract and is closely associated with the maintenance of normal physiological metabolism and overall health. Studies have shown that dysbiosis of the gut microbiota can lead to various diseases, including obesity, diabetes, hypertension, inflammatory bowel disease, and Alzheimer's disease. Therefore, conducting characteristic analyses of the gut microbial composition of laboratory animals can not only enhance the reliability of experimental outcomes but also facilitate their translational application. Sex differences represent a critical variable in biological research, significantly influencing the physiological functions, metabolic traits, and gut microbial composition of laboratory animals. However, a pronounced sex bias has been widely observed in many biological studies, thereby limiting the generalizability of results. This study focused on ten commonly used laboratory animals in life sciences, including mice, rats, guinea pigs, hamsters, rabbits, dogs, cats, non-human primates, miniature pigs, and chickens. Their gut microbial composition was summarized and related sex-specific differences of certain species were analyzed. Furthermore, by comparing the gut microbiota of laboratory animals with that of humans, this study offers novel perspectives for comparative medical research. In summary, this study not only deepens researchers' understanding of gut microbiota characteristics and sex-dependent variations across laboratory animal species but also provides practical guidance for selecting appropriate laboratory animals, constructing sex-specific disease models, and interpreting experimental results in scientific studies.

China National Accreditation Service for Conformity Assessment (CNAS) laboratory animal institutions accreditation is an important system for the management of laboratory animals in China. It is a third-party evaluation on Chinese characteristics dedicated to ensuring the quality and welfare of laboratory animals in China. The American Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC) certification provides global services about animal welfare evaluation and ethical certification, which are important for management and use of laboratory animals. This study compared and analyzed the nature of CNAS and AAALAC, the nature of CNAS accreditation and AAALAC certification, the evaluation principles, required documents, the evaluation process, the management of reviewers, and the acceptance of results, and discussed the differences and characteristics of the two evaluation systems for laboratory animal institutions.

Objective To compare and evaluate the improvement degree of spermatogenic dysfunction mice at different recovery periods after cyclophosphamide modeling. Methods Forty-eight male ICR mice aged 4-5 weeks with the body weight of approximately 18-20 g were randomly divided into three control groups and three model groups, with 8 mice in each group. Each mouse of three model groups was intraperitoneally injected with 60 mg/kg cyclophosphamide continuously from the 1^st to 7^th day of the experiment, while each mouse of three control groups was intraperitoneally injected with the corresponding volume of normal saline. Then these mice were continued to be fed for another 7, 14 and 21 days after cyclophosphamide injection, respectively. A corresponding control group was set for each model group. The mice in each group were sacrificed after blood collection through orbital veins at corresponding time points. Testis, epididymis and seminal vesicle were taken and weighed, and their reproductive organ indexes were calculated. Histopathological changes of testis and epididymis were compared after HE staining.Sperm quality analysis was used to determine sperm-related indexes. Serum reproductive hormone content, testicular oxidative stress level and testicular signature enzyme activity were detected by ELISA and related kits.Results Compared with the control group, on the 7^th, 14^th and 21^st day after cyclophosphamide treatment, the testicular index of mice in the model group decreased significantly (P<0.01). The epididymis index decreased significantly on the 7^th and 14^th day, and the seminal vesicle index decreased obviously on the 7^th and 21^st day (P<0.05). And the histopathological damage of testis and epididymis of the model group gradually alleviated over time. On the 7^th and 14^th day after cyclophosphamide treatment, the sperm count of the model group declined remarkably (P<0.01), the serum testosterone (T) level reduced (P<0.05), the malonaldehyde (MDA) content of testis increased significantly (P<0.01), the content of reduced glutathione (GSH) and superoxide dismutase (SOD) decreased obviously (P<0.05),the lactic dehydrogenase (LDH) activity of testis reduced obviously (P<0.05), the gamma-glutamyl transpeptidase (γ-GT) activity increased significantly (P<0.05), the latter two of which are important testicular signature enzymes. Therein on the 7^th day after cyclophosphamide treatment, the sperm motility decreased significantly (P<0.001), the rate of sperm malformation increased obviously (P<0.05), the serum levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) increased notably (P<0.01). Nevertheless on the 21^st day after cyclophosphamide treatment, the sperm-related indexes, the content of serum reproductive hormone, the level of testicular oxidative stress and the activity of testicular signature enzyme did not change significantly (P＞0.05). Conclusion The reproductive toxicity in mice was more apparent on the 7^th day after intraperitoneal injection with 60 mg/kg cyclophosphamide for seven days, at which time the more desirable spermatogenic dysfunction model of mice could be established. However, with the prolongation of the recovery period, the indexes of spermatogenic dysfunction in mice gradually recovered and approached the normal level on the 21^st day after cyclophosphamide treatment.

Objective By simulating the etiology of abnormal uterine bleeding-ovulatory dysfunction (AUB-O) and establishing a rat model of abnormal uterine bleeding (AUB), this study aims to provide an experimental platform for investigating pathological mechanisms and developing therapeutic drugs for AUB. Methods After acclimation, 24 adult (10-week-old) female SD rats were randomly divided into a normal control group (6 rats) and a model group (18 rats). The normal control group was housed in a barrier environment, while the model group underwent bilateral ovariectomy via dorsal approach in the same environment and rested for one week before starting to receive modeling drugs. In the model group, from Days 1 to 3 of modeling, each rat received a daily subcutaneous injection of 0.5 mg estradiol into the dorsal region. From Days 4 to 7, a daily subcutaneous injection of 5.0 mg progesterone was administered. On Day 6, rats received bilateral injections of 0.5 mL soybean oil per uterine cavity (total 1.0 mL) via the same dorsal surgical incision. On Day 8, mifepristone (10 mg/kg) was administered via oral gavage. The estrous cycle stage and its dynamic changes were continuously monitored during modeling. Uterine bleeding was recorded during the 48-hour observation period post-modeling. Serum and uterine tissue samples were collected from the model group at 0, 12, 24, 36, and 48 h after mifepristone administration, while the normal control group was sampled at 36 h. The samples were subjected to HE staining, serum sex hormone ELISA, immunohistochemistry, TUNEL apoptosis staining, Western blotting, transcriptome sequencing, and bioinformatics analysis for comprehensive evaluation of the AUB rat model. Results The AUB rats exhibited uterine bleeding, endometrial detachment and injury, incomplete uterine restoration, inflammatory cell infiltration in the endometrium, enhanced tissue apoptosis, and structural damage of the stroma, glands, and vasculature. Compared with the normal control group, the levels of serum follicle-stimulating hormone (FSH), estradiol, and luteinizing hormone (LH) were significantly increased in the AUB rats (P<0.05). The vascular density of the endometrium was significantly reduced (P<0.05). The expression of vascular endothelial growth factor (VEGF) was qualitatively observed to be markedly enhanced at the site of endometrial detachment but significantly decreased around the stromal blood vessels (P<0.01). Matrix metalloproteinase-9 (MMP-9) expression was qualitatively observed to be strongly upregulated at the site of endometrial injury but significantly reduced in the non-detached stroma and glands (P<0.01). Endometrial stromal cell apoptosis was significantly enhanced (P<0.01). The expression levels of fibroblast growth factor 2 (FGF2) and endothelin-1 (ET-1) in uterine tissues were significantly decreased (P<0.05). After comparing the transcriptome sequencing results of uterine tissues between AUB and normal rats, a total of 4 723 differentially expressed genes were identified, including 2 191 up-regulated genes and 2 532 down-regulated genes. KEGG enrichment analysis revealed that these differentially expressed genes were significantly enriched in pathways related to inflammation, immune apoptosis, cell signal transduction, proliferation and differentiation, and muscle contraction, among others. Conclusion An AUB rat model can be successfully established using a sequential administration protocol of estrogen, progesterone, and mifepristone to simulate the etiology of AUB-O. In this model, endometrial injury is associated with inflammation and apoptosis, with pathological manifestations influenced by abnormal vasoconstriction and impaired endometrial regeneration. This rat model closely recapitulates pathological characteristics of non-structural AUB observed in clinical practice, making it a validated experimental platform for exploring the pathological mechanisms and therapeutic interventions of non-structural AUB.