Analysis of transcriptome sequencing of sciatic nerves in Sprague-Dawley rats of different ages

An aging-induced decrease in Schwann cell viability can affect regeneration following peripheral nerve injury in mammals. It is therefore necessary to investigate possible age-related changes in gene expression that may affect the biological function of peripheral nerves. Ten 1-week-old and ten 12-month-old healthy male Sprague-Dawley rats were divided into young（1 week old） and adult（12 months old） groups according to their ages. mRNA expression in the sciatic nerve was compared between young and adult rats using next-generation sequencing（NGS） and bioinformatics（n = 4/group）. The 18 groups of differentially expressed mRNA（DEmRNAs） were also tested by quantitative reverse transcription polymerase chain reaction（n = 6/group）. Results revealed that（1） compared with young rats, adult rats had 3608 groups of DEmRNAs. Of these, 2684 were groups of upregulated genes, and 924 were groups of downregulated genes. Their functions mainly involved cell viability, proliferation, differentiation, regeneration, and myelination.（2） The gene with the most obvious increase of all DEmRNAs in adult rats was Thrsp（log2 FC = 9.01, P 〈 0.05）, and the gene with the most obvious reduction was Col2 a1（log2 FC = -8.89, P 〈 0.05）.（3） Gene Ontology analysis showed that DEmRNAs were mainly concentrated in oligosaccharide binding, nucleotide-binding oligomerization domain containing one signaling pathway, and peptide-transporting ATPase activity.（4） Analysis using the Kyoto Encyclopedia of Genes and Genomes showed that, with increased age, DEmRNAs were mainly enriched in steroid biosynthesis, Staphylococcus aureus infection, and graft-versus-host disease.（5） Spearman＇s correlation coefficient method for evaluating NGS accuracy showed that the NGS results and quantitative reverse transcription polymerase chain reaction results were positively correlated（rs = 0.74, P 〈 0.05）. These findings confirm a difference in sciatic nerve gene expression between adult and young rats, suggesting that, in peripheral nerves, cells and the microenvironment change with age, thus influencing the function and repair of peripheral nerves.

Effect of transforming growth factor beta and bone morphogenetic proteins on rat hepatic stellate cell proliferation and transdifferentiation

AIM: To explore different roles of TGF-β (transforming growth factor beta) and bone morphogenetic proteins (BMPs)in hepatic stellate cell proliferation and trans-differentiation.METHODS: Hepatic stellate cells were isolated from male Sprague-Dawley rats. Sub-cultured hepatic stellate cells were employed for cell proliferation assay with WST-1 reagent and Western blot analysis with antibody against smooth muscle alpha actin (SMA).RESULTS: The results indicated that TGF-β1 significantly inhibited cell proliferation at concentration as low as 0.1 ng/ml, but both BMP-2 and BMP-4 did not affect cell proliferation at concentration as high as 10 ng/ml. The effect on hepatic stellate cell trans-differentiation was similar between TGFβ1 and BMPs. However, BMPs was more potent at transdifferentiation of hepatic stellate cells than TGF-β1. In addition, we observed that TGF-β1 transient reduced the abundance of SMA in hepatic stellate cells.CONCLUSION: TGF-β may be more important in regulation of hepatic stellate cell proliferation while BMPs may be the major cytokines regulating hepatic stellate cell transdifferentiation.

Magnetic resonance imaging of hepatocellular carcinoma induced by diethylnitrosamine in Sprague-Dawley rats

Diethylnitrosamine (DENA) is able to induce various benign and malignant liver lesions in rats with a high success rate and a low mortality rate. It provides a more appropriate model that better simulates the various lesions occurring in humans than the usual model of tumor implantations. The aim of the present study was to evaluate MRI liver examination in Sprague-Dawley(SD) rats as a routine method to detect hepatocellular carcinoma (HCC) nodules induced by DENA and to follow up their growth. METHODS:Hepatic carcinogenesis was induced in 80 male SD rats using oral DENA solution. All animals were imaged for liver tumor detection with a 1.5 Tesla magnet (Siemens Sonata,Erlangen, Germany) using correspondence scan parameters and a radio-frequency knee coil. Macroscopic examinations were performed along the axial MRI sections to evaluate magnetic resonance imaging (MRI) findings, and histopathological assessment was also performed. RESULTS:No false negative results were obtained on MR images. Hepatic tumors in 72 rats were confirmed macro-scopically and 68 rats were detected by MRI till the 20th week. The smallest and the largest nodules detected by MRI were 2 mm and 37 mm in diameter respectively. The agreement rate of MRI with macroscopic observation was 39. 1% and 97. 4% respectively for 2 mm to 5 mm and more than 5 mm nodules. CONCLUSIONS:The hepatic tumor induced by DENA provides a more representative range of tumors for imaging diagnosis and interventional treatment. MRI is the best approach for scrutinizing pathological changes of rat livers in the period of observation.

Toxic Effects of Tetrabromobisphenol A on Thyroid Hormones in SD Rats and the Derived-reference Dose

The present study determined the thyroid hormone interference of tetrabromobisphenol A （TBBPA） in Sprague-Dawley （SD） rats, and the derived-reference dose （RfD） of different endpoint effects on mammals based on experimental results and data collection. Based on repeated exposure toxicity tests on mammals and extensive research, the present study used BMDS240 Software to derive a benchmark dose, and analyzed the accuracy and uncertainty, and similarity with other studies. Test results on triiodothyronine （T3）, thyroxine （T4）, and thyroid stimulating hormone （TSH） demonstrated that all the indicators presented a non-monotonous dose-effect relationship clearly, except TSH in male rats exposed to 0-1000 mg/kg BW per day. Therefore, RfDs were derived from different critical effects. In summary, RfD for mammals in the present study was found to be 0.6 mg/kg per day.

Hormetic Effects of Yttrium on Male Sprague-Dawley Rats

To evaluate hormesis induced by Yttrium（Y） nitrate in male rats, Y was offered to F0 mother rats and F1 offspring at concentrations of 0, 20, 80, and320 ppm daily from gestational day （GD） 0 through postnatal day 70（PND70）.The F1 offspring were evaluated with respect to motor function,learning and memory, and histopathology.

Comparative study on the difference of obesity model induced by two kinds of high fat diet in Sprague-Dawley rats

Objective: To explore the differences of obese Sprague-Dawley(SD)rats model induced by lard oil high-fat(HF)diet or purified HF diet. Methods: SD weanling rats were randomly divided into three groups: D1 group,where rats were fed by lard oil HF diet;D2 group,where rats were fed by purified HF diet;C group,where rats were fed on chow. After 12 weeks,diet-induced obesity rat(stop 33% based on weight)were selected for further study,and the rest rats from group D1 and D2 were excluded. The food intake and weight were weighted daily and weekly,respectively. The subcutaneous,visceral and total fat contents of rats was measured by 256-row CT scan and the Lee index was calculated accordingly. The kidney,liver,testis,spleen and heart were weighted respectively. Serum leptin and insulin levels were quantified. The pathology in liver and adipose tissues were analyzed by HE staining. Oral glucose tolerance test(OGTT)was used to compare the glucose tolerance ability. Serum total cholestero(lT-CHO),high density lipoprotein(HDL-C),low density lipoprotein(LDL-C),triglyceride(TG)and inflammatory cytokines IL-6,TNF-α were detected as well. Results: After 12 weeks,the body weight,subcutaneous fat,visceral fat,total fat mass,wet weight of liver,kidney and heart,area under blood glucose curve and the levels of serum insulin,leptin,T-CHO,LDL-C,TG,IL-6 and TNF-α in group D2 were significantly increased compared to those of group C and group D1. HDL-C of group D2 was markedly lower than that in group C(P<0. 05). The visceral fat,total fat content and HDL-C in group D1 were significantly different from those of group C(P<0. 05). Steatosis and enlarged adipocyte were found in the livers of rats in group D1 and D2,and the lesions were more significant in group D2. Conclusion: Purified HF diet was more effective in inducing metabolic abnormalities,steatosis,peripheral chronic inflammation in obese SD rat models. But lard oil HF diet was more economical when only inducing visceral steatosis was required.

Differences in action potential propagation speed and axon initial segment plasticity between neurons from Sprague-Dawley rats and C57BL/6 mice

Action potentials(APs)in neurons are generated at the axon initial segment(AIS).AP dynamics,including initiation and propagation,are intimately associated with neuronal excitability and neurotransmitter release kinetics.Most learning and memory studies at the single-neuron level have relied on the use of animal models,most notably rodents.Here,we studied AP initiation and propagation in cultured hippocampal neurons from Sprague-Dawley(SD)rats and C57BL/6(C57)mice with genetically encoded voltage indicator(GEVI)-based voltage imaging.Our data showed that APs traveled bidirectionally in neurons from both species;forward-propagating APs(fpAPs)had a different speed than backpropagating APs(bpAPs).Additionally,we observed distinct AP propagation characteristics in AISs emerging from the somatic envelope compared to those originating from dendrites.Compared with rat neurons,mouse neurons exhibited higher bpAP speed and lower fpAP speed,more distally located ankyrin G(AnkG)in AISs,and longer Nav1.2 lengths in AISs.Moreover,during AIS plasticity,AnkG and Nav1.2 showed distal shifts in location and shorter lengths of labeled AISs in rat neurons;in mouse neurons,however,they showed a longer AnkG-labeled length and more distal Nav1.2 location.Our findings suggest that hippocampal neurons in SD rats and C57 mice may have different AP propagation speeds,different AnkG and Nav1.2 patterns in the AIS,and different AIS plasticity properties,indicating that comparisons between these species must be carefully considered.

Analysis of Behaviour Pattern in Sprague-Dawley Rats Using Microwave Techniques

This communication presents a new method of detecting the behaviour pattern in Sprague-Dawley (SD) rats based on the measurement of the dielectric properties of blood plasma at microwave frequencies at different periods of time. The microwave measurements were performed by rectangular cavity perturbation method in the S-band of microwave frequency with the blood plasma collected from normal rats (Controls) as well as chemically induced rats (A&beta;). A change is observed in the dielectric properties of the A&beta;samples but not the controls samples at the extended period of time. This measurement technique is simple and the collection of blood from the rats is nonsurgical in nature. These results prove a new method of diagnosing Alzheimer’s Disease (AD) using microwave techniques.

The effect of Xin-Nao-Xue-Mai-Ning on SD rats with hypothyroidism and IRE1-XBP1 signaling

Objective:To investigate the effect of Xin-Nao-Xue-Mai-Ning(XNXMN)on hypothyroidism in SD rats and explore the effect of IRE1-XBP1 signaling pathway on hypothyroidism in rats,and to analyze the possible mechanism of XNXMN in the treatment of hypothyroidism.Method:Twenty-four male SD rats were given a 0.1%concentration of propylthiouracil(PTU)solution by gavage every day to establish a hypothyroidism animal model.After the completion of the model building,intervention with XNXMN.Observe the general conditions of rats,serum triiodothyronine(T3),tetraiodothyronine(T4),thyroid stimulating hormone(TSH)levels,X box binding protein 1(XBP-1)protein expression level,and perform statistical analysis.Results:XNXMN can improve the general condition of hypothyroidism rats,reduce serum TSH,increase T3,T4 and reduce the expression of XBP1 protein in thyroid endoplasmic reticulum.Conclusion:XNXMN can improve the symptoms of hypothyroidism rats and has the effect of treating hypothyroidism.Its mechanism of action may be related to the expression of IRE1-XBP1 signaling pathway proteins that regulate the unfolded protein pathway of the endoplasmic reticulum.

Effects of glycyrrhetinic acid on collagen metabolism of hepatic stellate cells at different stages of liver fibrosis in rats

INTRODUCTIONLiver fibrosis is a dynamic course leading tocirrhosis from a various chronic liver diseases. Thepathological basis of fibrosis is the disturbance ofproduction and degradation of the extracellularmatrix (ECM), which causes accumulation of ECMin the liver[1,2].

Effect of adrenalectomy on rat epididymidis

AIM: To investigate the effect of adrenalectomy (ADX) on the epididymidis of Sprague-Dawley rats. METHODS: The histological, biochemical (cholesterol protein, zinc, copper, alkaline and acid phosphatase aryl sulphatase, lactic dehydrogenase and leucine amino peptidase) and hormonal (FSH, LH and testosterone) changes of caput and cauda epididymis in ADX rats were observed. RESULTS: Organ wet weight, histological studies and morphometric measurements indicated a cellular degeneration in caput and cauda epididymis of ADX rats. Serum testosterone level was significantly lower in ADX than in sham-operated rats, while the serum FSH and LH were below the detection limit of 1 mIU/mL. The enzymatic activity was higher in ADX than in sham-operated rats. Epididymal zinc level increased whereas copper level decreased in ADX rats compared to the sham-operated. CONCLUSION: Adrenalectomy leads to degeneration of caput and cauda epididymidis epithelial cells as a result of decreased supply of testosterone.

Effect of Liangxuehuayu Recipe on hemorheology in rats with blood stasis syndrome

Objective:To investigate the effects of Uangxuehuayu Recipe on hemorheology in rats with blood stasis syndrome induced by mutifactor stimuli.Methods:SD rats were divided into control, model,Uangxuehuayu Recipe(high,middle and low dose,18,9,4.S g/kg accordingly).Except the control group,blood stasis model was established in the rest groups.The hemorheological parameters were measured and compared.Results:Blood viscosity at high,moderate and low level in rats with blood stasis significantly increased(P【0.05),but blood viscosity at high level and plasma viscosity was significantly decreased in rats induced by some stimuli after Uangxuehuayu Recipe were intra-gastrically administered for I weeks(P【0.01,P【0.05). Conclusions:Uangxuehuayu Recipe is effective in improving hemorheology,and has important application value in the prevention of occurrence and development of ischemic stroke.

Visceral hypersensitivity and altered colonic motility after subsidence of inflammation in a rat model of colitis

AIM:Irritable bowel syndrome(IBS)is a functional bowel disorder characterized by visceral hypersensitivity and altered bowel motility.There is increasing evidence suggesting the role of inflammation in the pathogenesis of IBS,which addresses the possibility that formerly established rat model of colitis could be used as an IBS model after the inflammation subsided. METHODS:Colitis was induced by intracolonic instillation of 4% acetic acid in male Sprague-Dawley rats.The extent of inflammation was assessed by histological examination and myeloperoxidase(MPO)activity assay.After subsidence of colitis,the rats were subjected to rectal distension and restraint stress,then the abdominal withdrawal reflex and the number of stress-induced fecal output were measured, respectively. RESULTS:At 2 days post-induction of colitis,the colon showed characteristic inflammatory changes in histology and 8-fold increase in MPO activity.At 7 days post-induction of colitis,the histological features and MPO activity returned to normal.The rats at 7 days post-induction of colitis showed hypersensitive response to rectal distension without an accompaning change in rectal compliance,and defecated more stools than control animals when under stress.CONCLUSION: These results concur largely with the characteristic features of IBS, visceral hypersensitivity and altered defecation pattern in the absence of detectable disease, suggesting that this animal model is a methodologically convenient and useful model for studying a subset of IBS.

Effect of cholecystokinin on cytokines during endotoxic shock in rats

AIM: To study the effect of cholecystokinin-octapeptide (CCK-8) on systemic hypotension and cytokine production in lipopolysaccharide (LPS)-induced endotoxic shock (ES) rats. METHODS: The changes of blood pressure were observed using physiological record instrument in four groups of rats: LPS (8mg.kg(-1),iv) induced ES; CCK-8 (40 microg.kg(-1), iv) pretreatment 10 min before LPS (8mg.kg(-1)); CCK-8 (40 micro.kg(-1), iv) or normal saline (control) groups. Differences in tissue and circulating specificity of the proinflammatory cytokines (TNF-alpha, IL-1beta and IL-6) were assayed with ELISA kits. RESULTS: CCK-8 reversed LPS-induced decrease of mean artery blood pressure (MABP) in rats. Compared with control, LPS elevated the serum level of IL-6 significantly (3567 +/- 687 ng.L(-1) vs 128 +/- 22 ng.L(-1), P【0.01), while contents of TNF-alpha and IL-1beta elevated significantly (277 +/- 86 ng.L(-1) vs not detectable and 43 +/- 9 ng.L(-1) vsnot detectable, P【0.01) but less extent than IL-6. CCK-8 significantly inhibited the LPS-induced increase in serum TNF-alpha IL-1beta and IL-6. LPS elevated spleen and lung content of IL-1beta significantly (5184 +/- 85 ng.L(-1) vs 1047 +/- 21 ng.L(-1) and 4050 +/- 614 ng.L(-1) vs not detectable, P【0.01), while levels of TNF-alpha and IL-6 also rose significantly but in less extent than IL-1beta. CCK-8 inhibited the LPS-induced increase of the cytokines in spleen and lung. In the heart, CCK-8 significantly inhibited LPS-induced increase of TNF-alpha (864 +/- 123 ng.L(-1) in CCK-8+LPS group vs 1599 +/- 227 ng.L(-1) in LPS group, P 【 0.01), and IL-1beta (282 +/- 93 ng.L(-1) in CCK-8+LPS group vs 621 +/- 145ng.L(-1) in LPS group, P 【 0.01). CONCLUSION: CCK-8 reverses ES, which may be related to its inhibitory effect on the overproduction of cytokines.

Norepinephrine transporter (NET) is expressed in cardiac sympathetic ganglia of adult rat

The sympathetic nervous system plays a cardinal role in regulating cardiac function through releasing the neurotransmitter norepinephrine (NE). In comparison with central nervous system, the molecular mechanism of NE uptake in myocardium is not clear. In present study, we proved that in rat the CNS type of NE transporter (NET) was also expressed in middle cervical-stellate ganglion complex (MC-SG complex) which is considered to control the activity of heart, but not expressed in myocardium. The results also showed that NET expression level in right ganglion was significantly higher than in the left, rendering the greater capacity of NE uptake in right ventricle, a fact which may contribute to the maintenance of right ventricular function under pathologic state.

Lansoprazole ameliorates intestinal mucosal damage induced by ischemia-reperfusion in rats

AIM: To investigate the protective effect of lansoprazoleon ischemia and reperfusion (I/R)-induced rat intestinalmucosal injury in vivo.METHODS: Intestinal damage was induced by clampingboth the superior mesenteric artery and the celiac trunkfor 30 rain followed by reperfusion in male Sprague-Dawleyrats. lansoprazole was given to rats intraperitoneally 1 hbefore vascular clamping.RESULTS: Both the intraluminal hemoglobin and proteinlevels, as indices of mucosal damage, significantlyincreased in I/R-groups comparion with those of sham-operation groups. These increases in intraluminal hemoglobinand protein levels were significantly inhibited by the treatmentwith lansoprazole at a dose of 1 mg/kg. Small intestineexposed to I/R resulted in mucosal inflammation that wascharacterized by significant increases in thiobarbituric acid-reactive substances (TBARS), tissue-associatedmyeloperoxidase activity (MPO), and mucosal content of ratcytokine-induced neutrophil chemoattractant-1 (CINC-1).These increases in TBARS, MPO activities and CINC-1 contentin the intestinal mucosa after I/R were all inhibited bypretreatment with lansoprazole at a dose of 1 mg/kg.Furthermore, the CINC-1 mRNA expression was increasedduring intestinal I/R, and this increase in mRNA expressionwas inhibited by treatment with lansoprazole.CONCLUSION: Lansoprazole inhibits lipid peroxidation andreduces development of intestinal mucosal inflammationinduced by I/R in rats, suggesting that lansoprazole mayhave a therapeutic potential for I/R injury.

Influence of BOL on hyaluronic acid,laminin and hyperplasia in hepatofibrotic rats

AIM: To study the anti-hepatofibrosis mechanism of Bie Jia Jian oral liquid (BOL). METHODS: The model was induced by subcutaneous injection of CCl(4). BOL was administered and the change of serum hyaluronic acid (HA) and laminin (LN) was observed and the degeneration of liver cells and the degree of fibre hyperplasia analyzed. Changes of ultra micro-structure in liver cells were observed in some samples. RESULTS: HA was reduced in both the groups with low and high dosage of BOL, which showed a remarkable difference as compared with that of the model group (low dosage group: 376.15 microg/L+/-35.48 microg/L vs 806.07 microg/L+/-98.49 microg/L P【0.05; high dosage group: 340.14 microg/L+/-30.18 microg/L vs 806.07 microg/L+/-98.49 microg/L P【0.05). The LN content of low and high dosage group of BOL was lower than that of model group (low dosage group: 71.99 microg/L+/-8.15 microg/L vs 133.94 microg/L+/-14.45 microg/L P 【0.01; high dosage group: 71.68 microg/L+/-11.62 microg/L vs 133.94 microg/L+/-14.45 microg/L P【0.01) and colchicine group (low dosage group: 71.99 microg/L+/-8.15 microg/L vs 118.28 microg/L+/-16.13 microg/L P 【 0.05; high dosage group: 71.68 microg/L+/-11.62 microg/L vs 118.28 microg/L+/-16.13 microg/L P 【0.05). Examined by Ridit, BOL could reduce the degeneration and necrosis of liver cells (chi(2)=11.99 P【0.05), the degree of fibre hyperplasia (chi(2)=13.24 P【0.05) and the pathological change of ultra micro-structure as well. CONCLUSION: The BOL has certain therapeutic effect on the experiment hepatofibrosis. Its mechanisms might include: protecting the function of liver cells, inhibiting excessive synthesis and secretion of extracellular matrix from hepatic stellate cells, relieving the capillarization of hepatic sinusoid, improving liver micro-circulation, and regulating immune function.

Study on Action of Acupuncture on Ventromedial Nucleus of Hypothalamus in Obese Rats

Effects of acupuncture on the spontaneous discharge of nerve cells and levels of monoamine neurotransmitters in ventromedial nucleus of hypothalamus (VMH) of the obese rats were investigated. Results indicated that the levels of tyrosine (Tyr) and dopamine (DA) were lowered, the levels of 5-hydroxytryptamine (5-HT) and 5-hydoxyindole acetic acid (5-HIAA) increased, and the frequency of the spontaneous discharge of nerve cells in VMH lowered in the obese rat group as compared with the normal group. When acupuncture obtained the effect of weight reduction, the frequency of spontaneous discharges of nerve cells in VMH were markedly increased, and the levels of Tyr, DA and tryptamine (Typ) and 5-HT/5-HIAA ratio elevated, and the 5-HT level lowered. It is suggested that the virtuous regulative action of acupuncture on VMH might be one of the key factors in acupuncture for weight reduction.

Effect of endotoxin on portal hemodynamic in rats

AIM: To study the effects of endotoxin on portal hemodynamic of normal and noncirrhotic portal hypertensive rats. METHODS: Normal rats were intraperitoneally injected with 0.1, 0.25, 0.5, 1.0, 2.0, 4.0mg.kg(-1) of lipopolysaccharide(LPS) respectively, portal vein ligation(PVL) and intrahepatic portal occlusion (IPO) rats as well as sham-operated rats were treated with an intraperitoneal injection of 1.0mg.kg(-1) of LPS, the portal vein pressure(PVP), portal venous flow(PVF), inferior vena cava pressure(IVCP) and portal vein resistance(PVR) were detected 4 hours after injection. RESULTS: PVF of the 5 groups of rats accepting intraperitoneal injection of LPS were increased from 14.0 to 18.0, 22.2, 26.2, 34.8, 39.6, 38.8 mL.min(-1) 4 hours after injection of LPS(P【0.01). PVP of the 4 groups of rats accepting more than 0.1mg/kg.b.w of LPS was increased from 1.04 to 1.25, 1.50, 1.80, 1.95, 2.05 kPa(P【0.01). The increments of PVF and PVP were in a dose-dependent manner of LPS. PVR of the 5 groups of rats was decreased from 51 to 42,44,48,45,44,47 kPa.min.L(-1) (P【0.05) and no dose-dependent manner was observed. PVF of PVL, IPO and sham-operated rats increased from 22.6 to 32.8, 22.0 to 28.0, 14.0 to 34.8 mL.min(-1) (P【0.01), and PVP increased from 1.86 to 2.24, 1.74 to 1.95, 1.04 to 1.80 kPa(P【0.01), PVR decreased from 71 to 61, 67 to 61, 52 to 44 kPa.min.L(-1) after intraperitoneal injection of 1mg.kg(-1) of LPS. The increments of PVF and PVP of PVL and IPO rats were significantly less than the sham-operated rats(P【0.01), There was no significant difference between the amounts of PVR decreased in the two groups of PHT model rats and sham-operated rats(P】0.05) after intraperitoneal injection 1mg.kg(-1) of LPS. CONCLUSION: Endotoxin could prompt portal hypertension of the normal and noncirrhotic portal hypertensive rats by increasing portal blood flow mainly.

Therapeutic effect of interleukin-10 on CCI_4-induced hepatic fibrosis in rats

AIM： To study the therapeutic effect of exogenous interleuldn-10 on CCl4-induced hepatic fibrosis in rats and its passible mechanisms. METHODS： Fourty-seven SD rats were randomly divided into control group （group N） and CCl4-induced hepatic fibrosis model group （group C）. After CCl4 was given for 9 wk, the model group was divided into three groups. Rats in group H were put to death immediately, rats in group T were treated with IL-10 for another three wk and then put to death, rats in group R recovered after three weeks and were then killed. The degree of hepatic fibrosis was measured by HE staining and histological activity index （HAI）. Histological activity index （HAI）, change of collagen types Ⅰ and Ⅲ were measured by Picrosirius staining. The expression of TNF-α, HHP-2 and TIMP-1 in liver tissue was measured by S-P immunohis tochemistry.RESULTS： CCl4- induced experimental rat hepatic fibrosis model was established successfully. The degree of hepatic fibrosis was markedly lower in group T than in groups H and R, and there was no difference between the two groups. The expression of collagen types I and III was significantly suppressed in group T and was slightly suppressed in groups H and R. The positive levels of TNF-α, HHP-2 and TIHP-1 in group H increased significantly compared to those in group N （P〈0.01）. The positive signals decreased significantly in groups T and R （P〈0.01）, but positive score was significantly lower in group T than in group R （P〈 0.01）. CONCLUS10N： Exogenous IL-10 can reverse CCl4-induced hepatic fibrosis in rats. IL-10 may exert its reversible effects on hepatic fibrosis by blocking CCl4-induced inflammation, inhibiting expression of HHP-2 and TIMP-1 and promoting resolution of collagen types Ⅰ and Ⅲ.