Abstract: Objective To observe and compare the effects of sex, antigen dose, injection frequency, and modeling time on a porcine thyroglobulin ( pTg)-induced experimental autoimmune thyroiditis ( EAT) mouse model. Methods A total of 80 SPF CBA/ J mice were selected to establish an EAT model under various conditions: sex ( 60 females and 20 males), antigen dose (pTg 50 μg, 100 μg, and 200 μg), and injection frequency and modeling duration (two injections in 28 days, three injections in 28 days, or three injections in 35 days). The effects of the different modeling strategies were compared using thyroid pathology scores, serum TgAb titers, serum TT4 levels, proportions of Treg and Th17 cells in the spleen, and the levels of related transcription factors. Results (1)Under the same modeling conditions, the degree of thyroid lymphocyte infiltration and EAT scores were lower, and the TgAb titers, proportion of Th17 cells, and IL-17A expression levels were significantly lower, in male mice than female mice. (2) TgAb titers, TT4 levels, proportion of Th17 cells, and expression levels of RORγt and IL-17A in the 50 μg model group were significantly lower than those in the 100 μg model group, and the expression level of Foxp3 in the 200 μg model group was significantly higher than that in the 100 μg model group. ( 3) EAT scores, TgAb titers, TT4 levels, proportion of Th17 cells, and expression levels of RORγt and IL-17A were significantly increased, and the proportion of Treg cells was significantly decreased, in the three injections in 28 days group. Conclusions Selecting female CBA/ J mice, increasing the antigen dose, increasing the modeling frequency and reducing the modeling time improved the EAT modeling effect.

Abstract: Objective To explore the temporal characteristics of anxiety-like emotions induced in the hyperalgesia priming rat model and the excitability changes in the anterior cingulate cortex (ACC) via dynamically observing the paw withdrawal thresholds ( PWTs ), anxiety-like behaviors, and immediate early gene ( c-Fos ) and paralbumin (PV) expression in the bilateral ACC at different time points. Methods The experimental rats were randomly divided into the sham hyperalgesic priming (SHP) group and the hyperalgesic priming (HP) group. In the HP group, 100 μL of 1% λ-carrageenan (Car) was subcutaneously injected into the left hind plantar ( first time), and after the PWT returned to the basic level, 25 μL of prostaglandin E₂(PGE₂ ) (100 ng) was injected into the left dorsum ( second time). In the SHP group, an equivalent volume of saline was injected (first time), and the same volume of PGE₂ was then injected (second time). We measured the PWT of the hyperalgesia priming rat model before modeling (base), and at 4, 24, 48, 72 h, and 10 d after Car injection, and at 1, 4, 24, 48, 72 h, 7 d, and 14 d after PGE₂ injection. Anxiety-like behaviors were observed in an open field (OF) at 24 h, 7 d, and 14 d after PGE₂ injection, in an elevated zero maze (EZM) at 24 h, 8d, and 15 d after PGE₂ injection. Immunofluorescence was used to detect the expression changes in c-Fos and PV-positive cells in the bilateral ACC. Results Compared with the SHP group, the PWTs of the HP group were significantly reduced at 4, 24, 48, and 72 h after Car injection (P< 0. 01) and recovered to the basic level at 10 d after Car injection (P> 0. 05); whereas, the PWTs significantly decreased at 4 h after PGE₂ injection and remained low for 14 days (P< 0.01). Compared with the SHP group, the total distance, the distance in the central area, the time in the central area, and the number of central zone entries in the OF of the HP group were significantly reduced at 24 h after PGE₂ injection (P<0.05). The total distance, the distance in the open arm, the time in the open arm, and the number of open arm entries in the EZM of the HP group were significantly reduced compared with the SHP ( P< 0.05). Interesting, there was no significant difference in anxiety-like behaviors in the OF and EZM at 7 d (or 8 d) and 14 d (or 15 d) after PGE₂ injection between the SHP and HP groups (P> 0.05). Compared with the SHP group, c-Fos positive expression in the bilateral ACC of the HP group was significantly decreased at 10 d after Car injection, while it was significantly increased at 24 h and 8 d after PGE₂ injection (P< 0.01), but there was no significant difference at 4 h and 15 d after PGE₂ injection (P>0.05). There was no significant difference in PV-positive expression in the bilateral ACC at 10 d after Car injection and 4 h, 24 h, and 8 d after PGE₂ injection (P> 0.05). PV-positive expression on the ipsilateral side of the HP group was significantly decreased at 15 d after PGE₂ injection compared with that of the SHP group (P< 0.01). Conclusions The hyperalgesia state in the hyperalgesia priming rat model can last for more than 14 days, accompanied by transient stress anxiety-like behaviors; however, it is not easy to induce persistent anxiety-like behaviors. The ACC excitability was in a state of compensatory inhibition before the transition, but was enhanced after the transition, characterized by increasing c-Fos expression in the early transition stage and decreasing PV expression in the later stage.

Abstract: Objective To verify whether Rev-erbα agonists can inhibit the inflammation of prostate tissue in mice induced by a high-fat diet, and to explore the mechanism of action. Methods C57B/ 6J male mice were divided into four groups: normal diet group, high-fat diet group, high-fat diet + SR9009 group, high-fat diet + control group. The body weight, peripheral blood cholesterol, triglyceride level, and prostate weight were measured. The prostate tissue was stained with hematoxylin-eosin (HE), subjected to transcriptome sequencing, and the expression levels of IL-6, IL-8, IL-1β, NF-κB-P65, and CCL21 were evaluated by immunohistochemistry. Results Compared with the normal diet group, the body weight, prostatic index, and the serum TG and TC levels of mice in the high-fat diet group were significantly increased, and the body weight, prostatic index, and serum TG and TC levels of the mice in the high-fat diet + SR9009 group were significantly lower than those of the high-fat diet + control group mice. HE staining showed that inflammatory cell infiltration into the prostate tissue of the mice in the high-fat diet group was increased compared with the normal diet group, and inflammatory cell infiltration into the prostate tissue of the mice on the high-fat diet was reduced after intervention with SR9009. The expression levels of Ccl21a, Ccr7, Tlr4, Il6, Il1b, and Cxcr2 were higher in the high-fat diet group than in the normal diet group, as demonstrated by heatmap analysis, but these expression levels were lower in the high-fat diet + SR9009 group than in the high-fat diet + control group. The differences in the expression intensity of IL-6, IL-8, IL-1β,NF-κB-P65, and CCL21a in the prostate of the four groups of mice were consistent with the differences in the sequencing result. Conclusions The circadian clock protein Rev-erbα can regulate the inflammation level of prostate tissue induced by a high-fat diet through the NF-κB pathway.

Abstract: Objective To establish a lung metastasis model based on Lewis subcutaneously-implanted tumors in C57BL/6 mice, and observe the pathological and ultrastructural changes in lung metastasis. Methods C57BL/ 6 mice were subcutaneously implanted with Lewis cells in the armpit of the right forelimb. The tumor volume was measured regularly and a survival curve was generated. Anatomical observations were performed on mice whose survival time was more than 35 days, hematoxylin-eosin (HE) staining was used to detect pathological changes in the lung tissue, and the ultrastructure of the lung tissue was observed by transmission electron microscopy. Results The subcutaneous tumor formation rate of the right forelimb axillary was 100% at 14 days after inoculation, and mortality occurred from 22 days, with a mean life span for the mice of (33. 00 ± 6. 98) days. Anatomically, typical metastases were observed on the lung surface, which had a round translucent appearance and surrounding hemorrhage. HE showed intense staining of the lung metastases, which were nearly round in appearance, with obvious boundaries with the surrounding tissue. The tumor cells were closely arranged and contained abundant capillaries. Under transmission electron microscopy, the tumor cells in the lung metastases showed significant atypia, including meganucleus, dicaryon, and singular nuclei. The cytoplasm of the cells contained a large number of glycogen particles and mitochondria, and cell junctions were evident between tumor cells. Conclusions Prolongation of the survival time resulted in the formation of typical lung metastases in mice with a subcutaneous tumor. The pathological and ultrastructural changes in lung metastases were consistent with the characteristics of malignant tumors.

Abstract: Objective To investigate whether the proportion of immune cells and related stem cells in the spleen of APP / PS1ΔE9 Alzheimer’s mice (AD mice) is different from that of normal mice. Methods The spleens of 9-month-old AD mice and their littermate normal control mice (six in each group) were collected. The ratio of CD4⁺T cells, CD8⁺T cells, B cells, monocytes, macrophages, and dendritic cells in the spleens of each group were detected by flow cytometry. At the same time, the ratio of cells with stem cell characteristics (C-kit⁺Sca-1⁺) among the above-mentioned cells was detected and compared. Results The AD mice showed significant differences in behavior compared with the control mice. However, there were no significant differences in the proportions of CD4⁺T cells, CD8⁺T cells, B cells, monocytes, macrophages, and dendritic cells in the spleens of AD mice compared with the control mice. The proportions of C-kit⁺Sca-1⁺cells in CD4⁺T cells, CD8⁺T cells, and B cells in the spleens of the AD mice were higher than those in the control mice, but because of individual differences, this was not statistically significant; the proportions of C-kit⁺Sca-1⁺cells in monocytes, macrophages, and dendritic cells were lower in AD mice than in the control mice. The difference between macrophages and dendritic cells was statistically significant. Conclusions Although the proportion of immune cells in the spleen of 9-month-old AD mice was not significantly different from that of normal control mice, in the myeloid cells of AD mice, the reserve of cells with stem cell characteristics was significantly lower than that of normal mice. Furthermore, compared with normal mice, the proportion of cells with stem cell characteristics among the lymphocytes was generally increased for AD mice. Taken together, these result indicated that AD mice had accelerated immune senescence compared with normal mice.

Abstract: Objective To study the pharmacokinetics of melatonin in rat plasma under conditions of normal gravity and simulated microgravity. Methods First, an ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS / MS) method was established to determine the concentration of melatonin in rat plasma. The simulated microgravity model of SD rats was established by 21 days of tail suspension. The rats in the normal gravity group were used as the control. After 21 days, the rats in both groups were administered melatonin (0. 27 mg / kg) by single gavage. Blood was taken from the jugular vein at 5, 10, 15, 20, 30, 40 min and 1, 1. 5, 2, 4 and 6 hours after administration, and the plasma was separated. The concentration of melatonin in the rat plasma was analyzed by the above-established UPLC-MS /MS method and the pharmacokinetic parameters were calculated. Results Within the concentration range of 0. 1 ~ 50 ng /mL, the linear relationship of melatonin in plasma was good. The relative standard deviation (RSD%) for both intra-day and inter-day precision was < 10. 99%. The extraction recoveries of low, medium, and high concentrations (0. 1, 25, and 50 ng / mL) were between 99. 3% and 115. 3%, and there was no obvious matrix effect. Compared with the normal gravity group, the pharmacokinetic parameters of melatonin in the plasma of simulated microgravity rats changed significantly. There were significant differences in time to reach maximum concentration ( T_max ), area under the plasma concentration-time curve (AUC_{0→6 h} ) , plasma clearance (CL), and mean residence time ( MRT_{0→6 h} )(P< 0. 05). The T_max, AUC_{0→6 h} , CL, and MRT_{0→6 h} values in the plasma of simulated microgravity rats were 1. 6, 3. 1, 0. 34, and 1. 56 times those of the normal gravity control rats, respectively. The bioavailability of melatonin in the microgravity rats was 312. 5% that of the normal gravity rats. Conclusions Compared with normal gravity, the pharmacokinetic characteristics of melatonin changed significantly after 21 days of simulated microgravity.

Abstract: Objective To study the protective effect and mechanism of action of Polygonati rhizoma polysaccharide (PSP) on the cognition deficits induced by simulating an enclosed space in mice. Methods Male ICR mice (n= 72) were randomly divided into four groups: control group, model group, positive control drug treatment group (huperzine-A), and PSP treatment group (100, 200, 400 mg / kg). With the exception of the control group, all other mice were subjected to chronic restraint stress (CRS) for 35 days to establish a mouse model of cognitive impairment (restraint intensity 10 h / d, 22:00 until 8:00 the next day) and body weight monitoring was conducted. Then, behavioral tests were performed, including an open field test, object recognition experiment, Morris water maze task, and a passive avoidance method. The levels of Superoxide dismutase ( SOD) and Malondialdehyde ( MDA) in the serum and the hippocampus, and the levels of Catalase (CAT), Corticosterone (CORT), and Acetylcholine (Ach) in the hippocampus were measured. Results The open field test showed that CRS did not affect the locomotor activities of any of the groups. Compared with the control group, the discrimination index (DI) of the CRS model group in the object recognition experiment was significantly decreased (P< 0. 01, P< 0. 001), the errors times increased and the latent period decreased in the passive avoidance test (P< 0. 05), and a longer escape latency in MWM(Morris water maze)was observed in the CRS model group ( P< 0. 05). Furthermore, in the CRS model group, the SOD and CAT levels were significantly decreased, MDA was increased, and CORT and Ach were significantly increased both in the serum and hippocampus (P< 0. 05, P< 0. 001). In comparison with the CRS model group, the above indicators were markedly reversed in the PSP groups. Conclusions The result suggested that PSP treatment can improve the cognitive impairment induced by simulating an enclosed space in mice, by mechanisms that involve the amelioration of oxidative stress damage, elevation of neurotransmitter levels, and regulation of the hypothalamic-pituitary-adrenal axis.

Abstract: Objective Three-dimensional ( 3D) clinostat has been widely used to simulate the effect of microgravity effect on plants, cells, and nematodes. Although its mechanism in models other than rodents has been discussed, no rodent model has been established and discussed mechanism. Methods Thirty 8-week-old male C57BL/ J mice were randomly divided into three groups: independent ventilation cage group (MC, n= 6), survival box group (SB, n= 12), and 3D clinostat group (CS, n= 12). After the study, loss of the left femur was detected using Micro-CT and serum metabolite changes were tested using metabolomics. Results After 3D clinostat treatment, the trabecular number decreased (P< 0. 05) and trabeculae spacing increased (P< 0. 5) in the CS group. Eighty-six metabolites in the CS group exhibited significant differences in metabolomics. These differential metabolites were mainly involved in protein digestion and absorption, and mineral absorption. Conclusions 3D clinostat microgravity induced bone loss and changes in metabolites and metabolic pathways in C57BL/ J mice.

Abstract: Objective To investigate the regulation mechanism of microglia activation, and learning and memory function, by electroacupuncture of the subgranular area of the dentate gyrus (SGZ) of depressed rats. Methods SD rats were randomly divided into four groups: the control group, model group, NLRP3 blocker group, and electroacupuncture group. The rat depression model was established by orphan rearing and chronic unpredictable gentle stimulation. The electroacupuncture group was administered electroacupuncture stimulation at the “Baihui” and “Yintang” acupoints for 20 min / d. The NLRP3 blocker group was injected with MCC950 solution (3 mg / kg) through the tail vein for 21 days. An open field experiment was used to record the autonomous activity of animals before and after modeling. The Morris water maze test was used to detect learning and memory function, and the immunofluorescence double-staining method was used to quantify and locate the protein expression of SGZ microglia marker Iba-1 and inflammasome Nod-like receptor 3. The relative expression levels of Caspase-1 and interleukin-1β in the SGZ were detected by real-time quantitative PCR. Results Compared with the control group, autonomous activity and learning and memory function were significantly reduced, the activation of SGZ microglia was obvious, the positive detection of NLRP3 protein was significantly increased, and the relative expression levels of Caspase-1 and IL-1β protein were also increased in the model group (P< 0. 01). Compared with the model group, the electroacupuncture group and the NLRP3 blocker group showed significantly improved autonomous activity and learning and memory function, and decreased positive detection rates of NLRP3+IBA-1 protein expression and relative expression of Caspase-1 mRNA ( P< 0.05, P< 0.01 ) and IL-1β mRNA. Conclusions Electroacupuncture improved the learning and memory ability of depressed rats, which may be related to the regulation of the activation state of microglia and the NLRP3 / caspase-1 signaling pathway in the subgranular area of the hippocampus.

Abstract: Objective To observe the effects of exposure to acute levels of particulate matter ( of < 2. 5 μm;PM2. 5) on lung inflammation and NLRP3 inflammasome activation in C57BL/ 6J mice and alcoholic fatty liver disease model mice, and to offer a target for the prevention and treatment of PM2. 5 exposure-induced acute lung injury. Methods Forty male C57BL/ 6J mice were randomly divided into four groups: control group, PM2. 5 group, alcoholic fatty liver disease (AFLD) model group, and AFLD + PM2. 5 group. Mice were fed the Lieber-DeCarli diet for eight weeks to establish AFLD; meanwhile, mice in the control group and PM2. 5 group were fed a control diet. From the ninth week, mice in the PM2. 5 group and AFLD + PM2. 5 group were exposed to ambient PM2. 5 by tracheal instillation for 7 consecutive days (once daily), and mice in the control group and AFLD+PM2. 5 group were instilled with saline at the same time. Animals were euthanized 24 h after the last exposure. Blood cells were measured, and pathological changes in the lung tissue were observed using hematoxylin-eosin (HE) staining. Interleukin (IL)-1β, IL-6, and TNF-α levels in the bronchoalveolar lavage fluid ( BALF) were determined using ELISA kits. The mRNA expression levels of nucleotidebinding oligomerization domain-like receptor protein (NLRP3) inflammasome-associated protein in the lung tissue were measured using real-time PCR. Results The lung septum in PM2. 5-treated mice was widened compared with the control group. Mice in the PM2. 5 group and the AFLD+PM2. 5 group had a higher number of white blood cells and a higher percentage of monocytes (P< 0. 01), significantly higher levels of inflammation cytokines (IL-6, IL-1β, and TNF-α) in the BALF ( P< 0. 01), and higher mRNA levels of NLRP3, Caspase-1, and ASC ( P< 0. 01) in the lung tissue compared with mice in the control group. In addition, the levels of IL-1β and TNF-α in BALF and the mRNA expression of NLRP3, Caspase-1, and ASC in the lung tissue of the AFLD+PM2. 5 group were significantly higher than those in the PM2. 5 group (P< 0. 05). Conclusions Acute PM2. 5 exposure may induce acute lung injury via activating the NLRP3 inflammasome in lung tissue, and AFLD aggravates PM2. 5-induced acute lung injury.

Abstract: Objective To isolate and identify primary hepatocytes from hepatitis B virus (HBV) transgenic mice, and provide a useful model for the study of HBV in vitro. Methods HBV transgenic C57 BL/ 6 mice were anesthetized and primary mouse hepatocytes (PMHs) were isolated and purified via a two-step infusion method. First, the liver was flushed with a calcium-free infusion, then digested with calcium-containing type IV collagen buffer. Hepatocytes were purified by centrifugation at low-speed and low-temperature three times, and the purified PMHs were confirmed by glycogen staining. In addition, the viability of PMHs within 7 days and the apoptotic ratio on days 1 and 3 were detected. Furthermore, PMHs were used to detect the effects of liver injury induced by hydrogen peroxide, including intracellular reactive oxygen species, mitochondrial membrane potential, oxidative stress factor level detection, and lactate dehydrogenase ( LDH) leakage. Results (1) The PMHs isolated from HBV transgenic mice showed typical hepatocyte morphology and positive glycogen staining. (2) The viability of hepatocytes increased after being adhered to a plate, and peaked at days 5 to 6, and then decreased gradually. (3) There was no difference between the apoptosis ratio on day 1 and day 3, with no spontaneous death. (4) Hydrogen peroxide had serious effects, including reactive oxygen accumulation, a loss in mitochondrial membrane potential, upregulation of oxidative stress factors, and LDH leakage. Conclusions Taken together, these data indicate that the PMHs of HBV can be successfully isolated and applied to liver injury research.

Abstract: Objective To explore the effect of aerobic exercise on endothelial dysfunction in obese rats and determine its mechanism of action. Methods An obese rat model was established by feeding with a high-fat diet for 8 weeks, then the rats were divided into three groups: the normal group, model group, and aerobic exercise group. The exercise protocol consisted of 8 weeks of medium-intensity aerobic exercise, six times per week. Body weight, body length, visceral weight, and visceral fat weight were measured, and Lee’ s index and the liposome ratio were calculated. Blood lipids were detected using a biochemical analyzer. The levels of serum thrombomodulin (TM) and visfatin were detected using an ELISA kit. Visfatin mRNA expression in epicardial adipose tissue was detected by an RT-PCR assay. Pathological changes in aorta morphology and structure were compared using the hematoxylin-eosin staining method. Results Compared with the normal group, the body weight, body length, Lee’ s index, visceral weight, visceral fat weight, liposome ratio, and the levels of TG, TC, LDL, TM, and visfatin in the model group were significantly increased (P< 0.05), the level of HDL was significantly decreased ( P< 0.01), and the expression of visfatin mRNA in epicardial adipose tissue was significantly upregulated (P< 0.01). Compared with the model group, body weight, Lee’s index, liver weight, perrenal fat weight, and the levels of TG, TC, LDL, TM, and visfatin in the aerobic exercise group were significantly decreased (P< 0.05), the level of HDL was significantly increased (P< 0.01), and the expression of visfatin mRNA in the epicardial adipose tissue was significantly downregulated (P< 0.05). Conclusions Aerobic exercise can reduce fat accumulation in obese rats, improve fat metabolism, downregulate the expression of visfatin in epicardial adipose tissue, inhibit visfatin secretion, and reduce pathological damage of the aorta to delay the process of endothelial dysfunction.

Abstract:Astronauts are exposed to microgravity, space radiation, loneliness, noise, vibration, sleep interference, and other negative factors during space flight. These factors interfere with the body’s steady state and cause a series of uncomfortable symptoms. An in-depth understanding of the mechanism by which these factors impact on the body is important to ensure the smooth implementation of crewed space missions. This study searched the metabolomics research on the impact of aerospace factors on the human body and experimental animals using the PubMed, CNKI and other databases are resources. The aim of this literature review was to gain a deeper understanding of how the body adapts to the extreme space environment and the molecular mechanisms responsible for the impact of aerospace factors on the body, so as to provide a basis for formulating personalized protective measures and improving the safety of space flight.

Abstract:With the rapid development of the manned spaceflight industry in China, research into space medicine is also constantly progressing. The space environment can lead to health problems such as space motion sickness, cardiovascular dysfunction, sleep disturbance, decompression sickness, and infectious diseases in astronauts on-orbit. Studies on the pharmacokinetics of drugs in the body in the space environment are urgently needed to provide a basis for effective clinical drug use in the space environment. This article focuses on the processes of drug absorption, distribution, metabolism, and excretion, and summarizes the pharmacokinetic changes and main mechanisms of action of drugs in the real on-orbit environment and during simulated weightlessness on the ground. Our findings provide a reference for the safe and rational use of drugs during spaceflight.

Abstract:Animal experiments have always been an important component of space exploration. Since the 20th century, the former Soviet Union and Russia have achieved major advances in the human space industry, which would not have been possible without the knowledge gained from animal experiments. Animal experiments were initially used to evaluate the possibility of humankind exploring space. “ Animal astronauts” were sent into space as the “ pioneers” of human space exploration. Such events were milestones in the development of the aerospace industry and greatly contributed to the construction of crewed spacecraft and space stations. This article reviews the development of space animal experiments in the former Soviet Union and Russia since the 20th century.

Abstract:Space animal experiments have always been an important part of human spaceflight. Groups of experimental animals have been sent into space as “ pioneers ”. This paper reviews the progress in space animal experimental research in the European Union and Japan since the 20th century. It summarizes the devices used for animal experiments and the result of those experiments, to provide a reference for aerospace life science research and medical research.

Abstract:Manned space flight in China has advanced to the stage of medium and long-term flights. During longterm space flight and space residence, weightlessness is an extreme aerospace-specific environment faced by astronauts. Weightlessness can have a serious impact on their physical and mental health, and may induce neuropsychiatric dysfunction, including cognitive decline in responsiveness, judgment, and decision-making. The particularity of space flight means that it is important to develop experiments on the ground to simulate space weightlessness, to explore the influence of space weightlessness, and to find protective countermeasures. This review summarizes experimental method to simulate weightlessness and the effect of weightlessness on body function.

Abstract:Space animal experiments are an important component of space-related life science research. Space animal experiments have made an important contribution to the exploration of life and to our understanding of how organisms from Earth adapt to space, while supporting the sustainability of human spaceflight. The Chinese space station has achieved in-orbit operation and will imminently carry out large-scale biological experiments. Here, we review the history of rodent experiments conducted in space by the United States since the 20th century, thereby providing a reference for China’ s future space animal experiments.

Abstract:The space environment challenges many of the biological processes in the human body, in particular, the central nervous system, cardiovascular system, skeletal muscle system, immune system, digestive system, and can even induce the remodeling of vital organs. Therefore, simulating the space flight environment through animal experiments is important for elucidating the mechanism of space stress injury and understanding potential protective measures against injury. This article expounds the stress injury and protection mechanisms of animal experiments, to provide a reference for future space exploration.