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Objective:To establish rabbit models of hemophilic arthritis (HA) through injecting blood and iron dextran into articular cavity, and to monitor the changes of joint structures and evaluate the effect of modeling with ultrasound. Methods: A total of 25 New Zealand white rabbits were divided into Group A, B (each n=5) and C (n=15). In group A and group B, 1 ml rabbit arterial blood was injected into the articular cavity with a total of 36 times (3 times a week) in group A and 24 times (twice a week) in group B. In group C, 1 ml of iron dextran was injected into the articular cavity of rabbits, and then the rabbits were averagely divided into 4 weeks group (C1 group), 8 weeks group (C2 group) and 12 weeks group (C3 group). The changes of synovium and cartilage of the articular cavity were observed with ultrasound. Pathological examination was performed after modeling, and the pathological changes of articular cartilage and synovium were observed. Results: After modeling, the synovium in group A ([4.46±0.47]mm) and C ([4.08±0.44]mm) measured with ultrasound were both thicker than in group B ([2.43±0.39]mm, both P<0.05). In group A and B, the thickness and the grade of blood flow signal of synovial membrane increased gradually during modeling. In group C, the thickness and blood flow signal of synovial membrane increased gradually in the early stage of modeling but gradually thinned or weakened. At the end of modeling, damage of articular cartilage could be observed with ultrasound in group A and C. Synovial hyperplasia, infiltration of inflammatory cells and destruction of cartilage similar to HA were observed in each group under light microscope. The pathological changes in groups A and C1 were more significant than those in other groups. Conclusion: Rabbit models of HA could be established through injecting blood or iron dextran into the articular cavity, both could reflect the characteristic manifestations of HA via symptoms, ultrasonic and pathological features. Iron induced arthritis models had advantages of short modeling period, simple operation and easy to be monitored with ultrasound.
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Objective: To establish the rat models of myocardial ischemia reperfusion-related no-reflow under non-artificial ventilator, to evaluate the models by morphology, hematological biochemistry and hemorheology, and to lay the foundation for studying the pathogenesis of cardiovascular diseases and evaluating the pharmacodynamics of drugs of cardiovascular diseases. Methods: Fifty healthy female Wistar rats were randomly divided into sham operation group (n=20) and model group (n=30). The myocardial ischemia reperfusion-related no-reflow rat models in model group were induced by ligation of left anterior descending coronary artery for 2 h and another 2 h for reperfusion. The rats in sham group were only threaded and not ligated. The model was evaluated by detecting the area at risk (AAR), area at infarct (AAD, area at no-reflow (AAN) of myocardium, the activities of creatine kinase MB (CK-MB), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) in serum, the whole blood viscosity, the plasma viscosity, the platelet adhesion rate (PAR), the platelet aggregation (PAG) of the rats. Results: Compared with sham operation group, the AAR, AAI, and AAN of myocardium, the activities of CK-MB, LDH, and AST in serum, the whole blood low shear viscosity (20/s), the middle shear viscosity (60/s), the high shear viscosity (120/s), the plasma viscosity, PAR, PAG (1, 3, 5 min) and the maximum platelet aggregation rate (MAPG) of the rats in model group were significantly increased (P<0. 05 or P<0. 01). Conclusion: The rat model of myocardial ischemia reperfusion-related no-reflow under non-artificial ventilator is successfully established. This method is characterized by simple operation, decreased injury to animals, higher stability of model construction, shorter experimental cycle and less cost.
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Objective@#To establish the in vitro porcine gastric model of submucosal eminence lesion and to evaluate its application to endoscopic submucosal dissection(ESD).@*Methods@#Silicone rubber impression materials and steel balls with diameters of 1 cm, 2 cm, and 3 cm were used to make three pairs of spherical cavities. And then raw ground beef was put into spherical cavities and boiled for 20 minutes to make spherical mass models. Six isolated porcine stomach with esophagus and duodenum were selected. The mass models with diameters of 1 cm, 2 cm and 3 cm were imbedded respectively into the submucosa of fundus, body, and antrum of porcine stomach through the incision on serosal layer. The submucosal masses were observed by endoscopy and endoscopic ultrasonography and ESD was performed.@*Results@#A total of 18 mass models were constructed in 6 porcine stomachs, of which 17 models were successfully established and 1 failed. Typical endoscopic characteristics of gastric submucosal eminence lesions were found in 17 models. Endoscopic ultrasonography showed that these models originated from submucosal layer and demonstrated mixed echo. There were no significant differences between mucosa of lesions and that of surrounding areas. ESD was successfully performed in the porcine gastric models of submucosal eminence lesions, and all models were not broken or detached.@*Conclusion@#The in vitro porcine gastric model of submucosal eminence lesions can well replicate disease status and provide a suitable model for study on endoscopic therapy of submucosal eminence lesion and training of endoscopists.
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[Abstract] Objective To explore the regular pattern of the changes of vascular endothelial growth factor (VEGF) and neuropilin-1 (NRP-1) of rat model in early (<48h) blast lung injury (BLI) and the correlation of such changes to the degree of lung injury. Methods The rat model of lung blast injury was established with reducing three-way pipe and fixed pressure pneumatic simulation device. Forty SD rats were randomly divided into 5 groups: control group (C), 1h after blast (B1h), 6h after blast (B6h), 24h after blast (B24h) and 48h after blast (B48h) group. The data were collected of concentrations of VEGF and NRP-1 in serum and lung tissue. The degree of lung injury was estimated. Results The levels of NRP-1 increased in both serum and lung tissue (P<0.01) and the level of VEGF decreased in lung tissue (P<0.05) in control group than in B groups. The concentrations of NRP-1 in serum and lung tissue were highest, and of VEGF in lung tissue were lowest in the group B6h. The lung injury score was positively correlated with the levels of NRP-1 in lung tissue (r=0.429, P=0.014). In group B6h, the lung injury score was negatively correlated with the levels of VEGF in lung tissue (r=–0.769, P=0.013). In group B48h, both the lung injury score and the wet and dry ratios (W/D) of lung tissue were positively correlated with the concentrations of VEGF in serum (r=0.777, P=0.012 and r=0.687, P=0.030, respectively). Pulmonary interstitial vascular rupture, alveolar hemorrhage, alveolar epithelial cell and capillary injuries, and accompanied by inflammatory cell infiltration were the basic pathological changes of BLI. Conclusion The levels of NRP-1 and VEGF in serum and lung tissue may vary with time and are correlated with the degree of lung injury in early BLI.
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Objective To explore the feasibility of interventional therapy in rat models of Budd-Chiari syndrome (BCS).Methods A total of 50 male clean SD rats were divided into model group and control group using random number table method,with 25 rats in each group.In the model group,BCS rat model was constructed by adopting partial ligation of the inferior vena cava (IVC),and the control group only had separation of surrounding tissues of IVC.Liver function was studied 12 weeks after postoperative raising,and digital subtraction angiography (DSA) and interventional therapy were performed,coupled with liver histopathology staining.Results Twenty BCS rats survived till the 12th week of raising,with the survival rate reaching 80.0％,and 22 survived in the control group.Compared with the control group,ALT [(43.1±5.5) U/L vs.(62.6±4.6) U/L] and AST [(84.7±26.5) U/L vs.(161.7±25.8) U/L)] in serum of rats in the model group increased,the differences were statistically significant (P＜0.05).HE staining showed that obvious hepatocyte necrosis and inflammatory cell infiltration were observed in BCS rats,and liver fibrosis was spotted via Masson staining.DSA examination found IVC obstruction in the model group,among which 14 (70.0％,14/20) received interventional therapy after successful probing of IVC obstructed segment,and 7 had balloon dilatation with a diameter of 3.5 mm,with 6 (85.7％,6/7) successfully dilatatedand the other 1 (14.3％,1/7) failed;the remaining 7 had balloon dilatation with a diameter of 4.5 mm,with 2 (28.6％,2/7) successfully dilatated,and the other 5 (71.4％,5/7) died of IVC rupture.Conclusion The BCS rat models by partial ligation of IVC can well simulate the pathophysiological changes and angiopathy characteristics of IVC obstructive BCS patients,which provide a platform for the basic research of interventional therapy of BCS.
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As a new model animal, zebrafish has been widely used in the research of the development and disease related to various organs, such as nervous, cardiovascular, digestive and hemopoietic system. Central nervous system ( CNS) disease is one of the leading causes of death and disability worldwide. There is still lacking of effective therapeutic strategies to treat most of the CNS diseases, due to the low ability of self-regeneration and recovery of the neurons after injury. In recent years, zebrafish has been proved to be an ideal vertebrate model to study some of the CNS diseases because their genetic physiology and other features are closed and similar to humans. The application of zebrafish in CNS diseases has contributed largely on understanding the mechanisms and on the therapy of CNS diseases. This review summarizes the recent progress of the applications of zebrafish on the study of CNS diseases.
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Objective The basic biological, echocardiography and gene sequencing parameters of mice overexpressing Slit2 gene (Slit2-Tg mice) were collected and evaluated, and to provide a reference for the application of Slit2-Tg mice in biomedical research. Methods Slit2-Tg and C57BL/6 J mice were inbred. The genotypes of the mice were determined by a PCR assay. The blood samples were collected for blood routine and biochemical tests. The tissues of main organs were collected for protein expression and pathological analysis. Echocardiography and transcriptome sequencing was carried out for analyzing the heart function and gene expression, respectively. Results The litter size was significantly higher in the Slit2-Tg mice than in C57BL/6 J mice. Human Slit2 gene and protein expressions were detected in the main organs of Slit2-Tg mice. Organ coefficient of spleen was significantly increased in Slit2-Tg mice, but the tissue structure appeared normal. There were significant changes in the counts of erythrocytes, platelets, eosinophils, and biochemistry of glucose, globulin, urea nitrogen, triglycerides, HDL, and atherosclerosis index. Echocardiography showed no significant differences in the morphology and function of the Slit2-Tg hearts except in the left ventricular anterior wall thickness at the end-diastolic state. Compared with the C57BL/6 J mice, 535 genes out of 17513 genes in the Slit2-Tg hearts were increased or decreased, mainly involving 15 biological process or signal transduction pathways. Conclusions This study has collected the biological parameters of Slit2-Tg mice and suggests that this model animal is suitable for the studies of cardiovascular diseases.
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Models of oxygen-induced retinopathy (OIR) have been built on several animals,including kitten,mouse,rat,rabbit,puppy and zebrafish.These models play an important role in studying the mechanisms and treatments of retinal neovascularization,which is partially mimicking the pathological process of retinopathy of prematurity (ROP) and proliferative diabetic retinopathy (PDR).As the extensive application of transgenic technology,animal models of OIR will provide more evidences on investigating the retinal angiogenic diseases.However,none of these OIR models is perfect to simulate human ROP completely,which still needs more comprehensive and profound exploration.
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Objective To establish a central serous chorioretinopathy (CSC) model on different strains of rabbits by intravenous injection of adrenaline,which may contribute to related researches of CSC.Methods This study was approved by Bioethics Committee of Fourth Military University and complied with Statement for the Use of Animals in Ophthalmic and Visual Research.Fundus fluorescein angiography (FFA) was initially performed on male New Zealand white rabbits (10),Belgium rabbits (5) and Chinchilla rabbits (10) to make sure that the retinas of subjects were normal.For the New Zealand white rabbits,adrenaline was injected via ear vein at a dose of 0.04 mg/kg once per day for the first 8 weeks and followed by a dose of 0.08 mg/kg for the next 4 weeks,while 0.04 mg/kg adrenaline was injected in the same way for 8 weeks in the Belgium rabbits and Chinchilla rabbits.FFA was performed every week after injection of adrenaline to evaluate the fluorescence leakage in ocular fundus.New Zealand white rabbits were sacrificed in 4 (3 rabbits),8 (3 rabbits) and 12 weeks (4 rabbits) after injection respectively,and Belgium rabbits and Chinchilla rabbits were sacrificed in the 8 weeks after injection.The eyeballs of the rabbits were enucleated to prepare the retinal sections for histopathological examination after hematoxylin-eosin staining.The results of FFA and retinal structure were compared among different strains of rabbits.Results No fluorescence leakage was found by FFA in ocular fundus,and the retinal structure was normal in all the 10 New Zealand white rabbits during the experiment.Fluorescence leakage was found by FFA in 2 Belgium rabbits at 1 week and 2 weeks after injection respectively,and retinal detachment and depigmentation of retinal pigment epithelium (RPE) with an enlarged intercellular space were shown by hematoxylin-eosin staining.For the Chinchilla rabbits,fluorescence leakages were found in 7 rabbits throughout the whole period of adrenaline administration.Circumscribed retinal detachment,depigmentation of RPE with enlarged intercellular space were also found in leakage lesions.Conclusions Repeated intravenous injection of adrenaline can induce CSC-like lesions in colored rabbits but not in albino rabbits.
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Obstructive jaundice is a common disease that greatly threatens human health.In order to better investigate the pathogenesis of obstructive jaundice,pathophysiological changes during disease progression,and treatment measures,the establishment of a stable animal model of obstructive jaundice becomes the basis for the research on various types of obstructive jaundice.This article elaborates on the advantages and disadvantages of the animal models of acute,progressive,chronic fluctuant,malignant,and reducible obstructive jaundice,as well as their application in clinical practice.These animal models have certain limitations in reflecting the development and progression of target disease.Most animal models are established by surgery or external physical and chemical damage,and there are still no mouse models of gene knockout or overexpression.Future research will focus on the stable animal models of chronic and progressive obstructive jaundice and special types of obstructive jaundice.
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Therapeutic intervention and rehabilitation after spinal cord injury (SCI) are currently confronted with tremendous challenges in basic and clinical medicine.The pathological process of SCI starts with the primary injury process directly caused by a mechanical force and follows the secondary injury process caused by microcirculation disorders and inflammatory responses.In this review,we interpret the neurobiological mechanisms underlying SCI.Damage to descending motor pathways and ascending sensory pathways interrupt their feedback and/or feedforward control of movement planning and modulation.To some extent,it also affetcs the normal function of local neural circuits with partial plasticity and independence.The animal models for SCI include transection models,contusion and compression models,ischemia-reperfusion injury and chemical injury models.Basic and translational studies in SCI have achieved remarkable progress in various aspects,including the gene network regulation of axonal regeneration,cell implantation,biomaterials applications,neuronal protection,neurostimulation and functional rehabilitation training,applications of artificial intelligence and brain computer interface.Obviously,future trends in basic and translational studies in SCI research will be enhancement of interdisciplinary research,cutting-edge technology application for clinical rehabilitation,database sharing and data standardization.
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Objective To investigate the effect of prevascularized tissue-engineered bone graft on regeneration of femoral bone defects in rats.Methods Models of femoral bone defect were created at the bilateral hind limbs of 20 healthy female 10 week-old rats which were divided into 2 even groups randomly (n =10).In group A,conventional tissue-engineered bone grafts were transplanted into the femoral bone defects;in group B,tissue-engineered bone grafts and vascular bundles were implanted into the femoral defects.At 1,4 and 8 weeks after operation,3 rats were sacrificed each time in each group to harvest samples.The remaining one in each group served as a spare animal.Regeneration of bone defects and degradation of scaffolds were assessed by radiologic modality and hematein eosin staining.Results At week 1,the new bone ratio (BV/TV) was 5.47％ ± 1.90％ in group A and 8.49％ ± 1.26％ in group B,showing no significant difference (P ＞ 0.05);at weeks 4 & 8,the BV/TV were 17.54％ ±2.04％ and 39.73％ ± 4.01％ in group A,significantly lower than those in group B (25.32％ ± 2.15％ and 53.22％ ± 2.94％) (P ＜ 0.05).At weeks 1 & 4,the scaffold degradation ratios (RSV/SV) were 97.33％ ± 2.52％ and 80.60％ ±4.00％,showing no significant differences from those in group B (95.67％ ±3.51％ and 75.22％ ±6.20％) (P ＞ 0.05).At week 8,the scaffold degradation ratio in group A (65.46％ ±4.51％) was significantly higher than that in group B (50.19％ ±4.91％) (P ＜ 0.05).At week 8,hematein eosin staining showed better integration of scaffolds with the femur,faster degradation of the interior scaffolds and greater osteogenetic activity in group B.Conclusion Prevascularization of tissue-engineered bone graft may increase new bone volume and scaffold degradation rate,promoting repair of femoral bone defects in rats.
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Objective To establish a pure planarian Dugesiaasexual strain in China.Methods The planarian worms were collected from a wild stream,and then made the worm grow after amputation in the lab.To establish an asexual strain through cutting and culturing for the single worms.Results After ten years and more than ten thousand experiments,an asexual pure planarian strain Dugesia ZB-1 originated from Shandong Zibo area was established.It grows stably under laboratory controlled conditions.Conclusions The establishment of DugesiaZB-1 Priovides a solid foundation for further experiments and promoting planarian research in our country and participation in the field of the international planarian research.
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Objective To establish an easily reproducible rabbit model of acute pulmonary embolism (APE) with right ventricular dysfunction (RVD).Methods Two gelfoam strips (5 rnm×5 mm× 10 mm) were squeezed and were introduced into the pulmonary arteries of each healthy rabbit (n=12).Pulmonary and systemic hemodynamic function were recorded.All rabbits underwent CT pulmonary angiography (CTPA) and pathological examination after the introduction of APE.Results All gelfoam strips located in the bilateral lower lobe arteries.Compared with baseline mean pulmonary artery pressure (mPAP) ([9.75±1.75] mmHg),mPAP increased to (20.58 ± 5.86) mmHg immediately after embolism (P ＜ 0.001),and then decreased to (18.78 ±4.80) mmHg 1 h after embolism (P＜0.001).Right ventricle/left ventricle diameter ratio (RV/LV) increased from baseline (0.67±0.09) to (1.90±0.28) 45 min after embolism (P＜0.001).Conclusion An easily reproducible rabbit model of APE with RVD are established and may be suitable for study of APE pathophysiology.
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Objective To compare the repair effect on renal function between different times of bone marrow mesenchymal stem cells (BMSCs) transplant via renal artery route in experimental rats with adriamycininduced nephropathy.Methods Adriamycin-induced nephropathy model was established in 32 rats through injection of adriamycin though the caudal vein.Based on the scheduled times of BMSCs transplant,the experimental rats were randomly and equally divided into M0 group (zero time),M1 group (one time),M2group (2 times) and M3 group (3 times) with 8 rats in each group.Other 8 SD rats were used as normal control group (N group).Single dose of 0.5 rnl BMSC suspension (2×106 cells/ml) was transplanted to the rats of M0 group (zero time),M1 group (one time),M2 group (2 times) and M3 group (3 times),for the rats of the groups not receiving BMSC transplant a single dose of 0.5 ml L-DMEM culture medium,used as a placebo,was adopted to replace BMSC suspension.The transplant interval was one week.Before transplant as well as one and two weeks after last time of transplant,the serum urea nitrogen,serum creatinine,24 h urine protein and 24 h urine microprotein were tested,and one week after last time of transplant pathological sections were made for laser focusing microscope examination to observe renal pathological changes and the distribution of BMSC cells in the kidney.Results The values of serum urea nitrogen,serum creatinine,24 h urine protein and 24 h urine microprotein determined at each observation time point in M0 group,M1 group,M2 group and M3 group were significantly higher than those in N group (P＜0.001).The values of 24 h urine protein and 24 h urine microprotein determined at one week after last time of transplant in M2 group and M3 group were strikingly lower than those in M1 group (P＜0.05),but these differences between M2 group and M3 group were not statistically significant (P=0.063).Conclusion For the treatment of adriamycin-induced nephropathy in experimental rats,two times of using BMSCs transplant via renal artery route can achieve optimal curative effect.
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Obstructive jaundice is a common disease that greatly threatens human health.In order to better investigate the pathogenesis of obstructive jaundice,pathophysiological changes during disease progression,and treatment measures,the establishment of a stable animal model of obstructive jaundice becomes the basis for the research on various types of obstructive jaundice.This article elaborates on the advantages and disadvantages of the animal models of acute,progressive,chronic fluctuant,malignant,and reducible obstructive jaundice,as well as their application in clinical practice.These animal models have certain limitations in reflecting the development and progression of target disease.Most animal models are established by surgery or external physical and chemical damage,and there are still no mouse models of gene knockout or overexpression.Future research will focus on the stable animal models of chronic and progressive obstructive jaundice and special types of obstructive jaundice.
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Background Suture stitching is currently the standard treatment for corneal penetrating injuries.The shortcomings of suture stitching have led to the exploration of non-sutured surgical methods.Tissue adhesive is a promising non-suture replacement procedure.Objective This study was to observe the effect of fibrin glue on large irregular rabbit corneal penetrating injury.Methods Eighteen pure white healthy rabbits were randomly divided into suture group and adhesive group.A total length of 6-mm non-self-sealing corneal penetrating injury in nonpupillary-area of the right eye formed with a 15° corneal puncture knife was repaired with fibrin glue plus temporary suture and therapeutic corneal contact lens (9 eyes) or with 3 to 5 interrupted 10-0 nylon sutures (9 eyes) with the fellow eyes acted as the internal controls respectively.Operative time was compared between the two groups.Clinic observation was performed with slit lamp microscope.Animals were humanely sacrificed for histologic examination at week 1,3,and 8 to evaluate wound healing.Results The average operation time was (3.48±0.48) minutes in the adhesive group,which was significantly lower than that in the suture group ([7.77 ± 1.30] minutes) (t =9.28,P＜ 0.01).The postoperative slit lamp microscope observation indicated corneal wounds were quickly and regularly healed in the glued corneas compared with the stitched ones.The histologic examination revealed that glued corneas had regular healing,mild inflammation,and no corneal neovascularization,while sutured corneas showed irregular fibrin arrays,a large number of inflammatory cells and macrophages infiltration around the suture,heavy inflammatory response.Neovascularization was found at week 3 postoperatively.Conclusions Fibrin glue combined with temporary suture and therapeutic corneal contact lens is an effective treatment in sealing large irregular corneal wounds with considerable advantages over traditional sutures,ircluding simplified operative technique,short surgery time,less postoperative irritation,mild inflammation,more regular wound healing,short healing time,and no corneal neovascularization.
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Objective To detect and analyze the HBV?related indexes in the urine of HBV transgenic mice and further understand the biological characteristics of transgenic mice, and to clarify the tissue sources of HBV?related indexes. Methods HBV?related indexes in the urine of transgenic mice were tested using enzyme?linked immune sorbent assay ( ELISA ) and fluorescence quantitative PCR ( real?time RCR ) . The tissue sources were confirmed by several experiments, i. e. hydrodynamic transfection of mice, RNA interference to inhibit HBV?expression in the transgenic mice, and to infect normal mice with HBV?positive serum from patients. Results Expression of HBsAg, HBeAg and HBV?DNA was present in the urine of transgenic mice, of which the HBsAg expression level was high (6674 ± 619?8 IU/mL), but lower than that in the serum (16470 ± 2704 IU/mL). The level of HBsAg expression in the urine of male mice was higher than that in female mice. The level of HBeAg expression in the urine was lower and the HBeAg positive rate of urine was higher than that of blood, and the levels of HBeAg expression showed significant inter?individual and inter?sexual differences. HBV?DNA level reached 103 -105 copy/mL in the urine, but no related antibody expression was detected. The experiments such as hydrodynamic infection test indicated that the HBV?related indexes in the urine are derived from replication in the kidneys rather than secreted from the liver, entered into the blood circulation, and discharged from the urine. The kidneys are an independent expression site of HBV. Conclusions The expression of HBV?related indexes is present in the urine of transgenic mice and it is a long?term expression along with the age in months, of which the expression levels of HBsAg and HBV?DNA are rather high and stable. HBsAg titer in the urine of the male mice is higher than that of female mice. HBeAg expression level in the male mice is more stable compared with that in female mice. No expressions of various kinds of antibodies have been found in the urine. The kidneys are an independent expression site of HBV.
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To summarize and introduce the available methods of establishing rabbit models of VX2 nasopharyngeal carcinoma ( NPC) , and to explore the improvements at each stage in the preparation of the rabbit models, in order to provide a favorable animal model for future experimental research.
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Objective To explore different methods for establishing animal models of Ureaplasma urealyticum ( UU) infection and to select the best method of establishment of this disease .Methods SPF female BALB/c mice and Wistar rats were multiple-infected with small dose of UU liquid or single-infected with high-dose UU liquid, pretreated with estradiol benzoate, to establish models of Ureaplasma urealyticum infection.Cervical secretion was taken for UU culture at 14, 28, 42 and 56 days after the first time UU treatment , and the reproductive organs were taken for histopathological examination.Results Gross examination of the UU-infected rats showed generally less serious lesions than the mice .The low-dose estrogen group was worst , showing hyperemia and edema , cervical hypertrophy , hydrosalpinx , enlargement , and more rigid with poor elasticity .Significant differences were observed in the vaginal UU colonization rates between the low -dose estrogen and low-dose non-estrogen groups , high-dose estrogen and non-estrogen groups , low-dose estrogen and high-dose estrogen groups, low-dose estrogen and non-estrogen groups, in both the mice and rats (P<0.05 for all).The same dose estrogen treatment caused a higher UU colonization rate in the mice than rats ( P<0.05 ) .Histological examination showed that the low-dose estrogen treated rats had no obvious pathological changes , except loose tissue edema in some rats , but apparent pathological changes were observed in the low-dose estrogen treated mice .Conclusions The vulvar lesions in the mice are worse than in the rats .Estrogen pre-treatment can increase the Ureaplasma urealyticum colonization rate in the animals.The UU colonization rate in the vagina of mice is higher than in the rats , and multiple low-dose UU treatment produces a higher UU colonization rate than a single high-dose UU treatment.Therefore, BALB/c mice are more susceptible to Ureaplasma urealyticum infection, with more serious pathological changes , and are more suitable for experimental studies of related diseases .