Abstract:Objective To observe the changes of mechanical pain thresholds and autophagy related proteins microtubule-associated protein 1 light chain 3 (LC3) and sequestosome 1 (SQSTM1 also known as p62) expression levels in the C57BL/6 mouse models of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), and provide animal experimental evidence for CP/CPPS pain and autophagy study. Methods 36 male C57BL/6 mice were randomly divided into three groups:the model group, control group and naïve group. The CP/CPPS model was established by subcutaneous injection in the lower abdomen region with suspension liquid, containing protein extract of male SD rat prostate gland and complete Freund adjuvant. At 1month and 6 months after modeling, the mice were sacrificed and prostate tissues were harvested for histological examination using HE staining. Mechanical tactile hyperalgesia was measured with von Frey filaments. The autophagy-related proteins LC3 and p62 expression levels were detected by immunohistochemistry, respectively. The average IOD was measured by Image Pro Plus 6.0, and the statistical analysis was performed with GraphPad Prism 5 software. Results The histopathology showed the appearance of chronic prostatitis in the model group, representing hyperplasia and lymphocytic infiltration to a different degree and lasted for 6 months after modeling. Moreover, prostate intraepithelial neoplasia (PIN) appeared in the model group at 6 months after modeling, characterized by the disappearence of basement membrane and obvious nuclear abnormality, while the control and naïve groups showed normal histology during the 1-6 months. Compared with the control and naïve groups, the mechanical pain threshold in the model group was significantly decreased along with the time from (0.353±0.154) g at 0 week to (0.008±0.00) g at 22 weeks (P<0.05). The average IOD of LC3 and p62 expression in the model group was significantly increased with timing from[(2.767±0.464)%, (2.872±1.642)%] at 1month to[(13.501±1.900)%, (9.07±0.49)%] at 6 month, P<0.05. Conclusions A CP/CPPS model is successfully established in C57BL/6 mice. For the model group, the mechanical pain threshold is decreased and autophagy levels are increased gradually with time. These phenomena show that chronic inflammation microenvironment may promote pain and autophagy activity in the prostate, which is closely related with the occurrence and development of prostatic intraepithelial neoplasia.

Abstract:Objective To find an ideal animal model of acute respiratory distress syndrome (ARDS) through investigating the characteristics of three "two-hit" animal models of ARDS. Methods Forty-eight SD rats were randomly divided into 4 groups:Control group[2.5 mL/kg normal saline (NS) i.v. given at 0 min and 30 min]; OA+OA group[0.5 mL/kg oleic acid (OA) i.v. given at 0 min and 30 min]; LPS+LPS group[2.5 mg/kg lipopolysaccharide (LPS) i.v. given at 0 min and 30 min]; and OA+LPS group[0.5 mL/kg OA i.v. given at 0 min and 2.5 mg/kg LPS, i.v. given at 30 min]. The samples were collected at 5 h after the second drug injection. White blood cells count (WBC), polymorphonuclear leukocyte ratio (PMN%), total protein concentration, tumor necrosis factor α (TNF-α) level in bronchoalveolar lavage fluid (BALF), arterial blood gas analysis and lung wet-dry weight ratio (W/D) were measured, respectively. Pathological changes in the lung tissues were observed and histological scores were evaluated. Results Compared with those in the control group, PaCO₂, WBC, PMN%, total protein concentration and TNF-α levels in BALF were significantly increased, while PaO₂ was dramatically decreased (P<0.01) in the OA+OA, LPS+LPS and OA+LPS groups. The levels of protein concentration in BALF and lung W/D ratio in the OA+LPS group were significantly higher than these in the LPS+LPS group (P<0.05 for all), but had no statistically significant difference compared with these in the OA+OA group. The levels of WBC, PMN% and TNF-α in BALF in the OA+LPS group were significantly higher than those in the OA+OA group (P<0.05), but not significantly different from those in the LPS+LPS group. The most typical pathological changes and the highest pathological scores were found in the OA+LPS group. Conclusions All the three different Methods including OA+OA, LPS+LPS, and OA+LPS can be used to establish "two-hit" animal models of acute respiratory distress syndrome. The "two-hit" animal model of acute respiratory distress syndrome induced by OA+LPS is more closer to clinical ARDS and is useful for studies on the pathophysiology of ARDS, and is an ideal "two-hit" animal model of ARDS.

Abstract:Objective To observe the role of resting metabolic rate (RMR) in evaluation of animal model of glucocorticoid-induced Kidney Yin deficiency and Kidney Yang deficiency syndrome. Methods Male BALB/c mice were divided into control group, model group, Jinkuishenqi pill group, and Zhibaidihuang pill group. The later 3 groups were given drinking water containing corticosterone (first dissolved in 1% ethanol, with a final concentration of corticosterone 100 μg/mL). The control group was given drinking water containing 1% ethanol. RMR was measured by closed fluid pressure respirometer. At the end of the experiment, the mice were sacrificed to detect the weight index of perirenal fat, epididymal fat, quadriceps, and tibialis anterior muscle. ELISA assay was used to detect the level of serum hormones. Histological changes of the liver and kidney were examined by HE staining. Malondialdehyde (MDA) content, succinate dehydrogenase (SDH) activity, cytochrome c oxidase (COX) activity and ATP level were measured. Results Compared with the control group, the RMR of model group was significantly increased at the 2nd day of beginning of the experiment, reached the highest on the 4th day (P<0.01), then decreased gradually, and to the 66th day, the RMR was significantly reduced (P<0.05). Use of corticosterone resulted in decrease of the serum levels of thyroxine (T4), muscle mass index, SDH activity, COX activity and ATP level, while increase of fat mass index and MDA level. The two Kidney nourishing prescriptions reduced animal mortality, and reduced the content of MDA in liver tissue. But only Jinkuishenqi pill increased the RMR at the 4th and 66th days (P<0.05), and significantly improved the liver SDH activity, COX activity and ATP level (P<0.01). The Zhibaidihuang pill showed no such effects. Conclusions RMR can be used for evaluation of animal model of Kidney Yin or Kidney Yang deficiency induced by glucocorticoids.

Abstract:Objective To investigate the growth curve, breeding rate, and blood physiological and biochemical parameters in Npc1 gene mutant mice (Npc1^-/-) for providing theoretical evidence in research on Niemann-Pick disease type C1 (NPC1) patient. Methods 1) The body mass of Npc1^-/-, Npc1^+/-, and Npc1^+/+ mice (n=120; 60♀, 60♂) was measured from 0 to 77 days; (2) As Npc1^-/- mice were born only by the mating Npc1^+/- mice, the breeding rate of Npc1^+/- mice was counted here from the 1st to 4th generation; (3) The blood physiological and biochemical parameters were measured on both Npc1^-/- and Npc1^+/+ mice at 60 days. Results 1) Compared with the wild type controls,the body weight of Npc1^-/- mice was progressively increased up to 7 weeks and then decreased, and died around 11 weeks. The body weight of the Npc1^+/- and Npc1^+/+ mice was increased as time went on. After 4 weeks, the male mice showed a higher weight gain than the females; (2) The generations of Npc1^+/- mice had no significant difference in mating-parturition interval, litter size, weaning litter and the number of male and female (P>0.05), but the weaning rate of the 2nd generation was significantly higher than that of the 1st generation (P<0.05); (3) The hematological parameters showed a significant difference only in mean corpuscular hemoglobin (MCH) and mean peroxidase index (MPXI) between the Npc1^-/- and Npc1^+/+ mice (P<0.05). No significant difference was found in other hematological parameters (P>0.05). Among the biochemical parameters, aspartate aminotransferase (AST), glucose (GLU), lactate dehydrogenase (LDH), potassium (K) and copper (Cu) had a significant difference between the Npc1^-/- and Npc1^+/+ mice (P<0.05). Conclusions 1) The growth curves of Npc1^-/-, Npc1^+/-, and Npc1^+/+ mice are different due to different genotype and sex; (2) The reproduction rates of Npc1^+/- mice have no significant difference among different generations; (3) The blood physiological parameters (MCH, MPXI) and biochemical parameters (UREA, AST, GLU, LDH, K, Cu) are significantly different between Npc1^-/- and Npc1^+/+ mice.

Abstract:Objective To compare the ameliorating effect of collagen peptide chelated calcium (CPCC) and estrogen on the bone quality in ovariectomized rats in order to serve the development of safe drugs for prevention of osteoporosis (OP). Methods Bilateral ovariectomized rats were divided into ovariectomized group (OVX), sham group, 17β-estradiol injection group (OVX+E₂) and CPCC gavage group (OVX+CCCP). Bone and serum indices of these groups were assessed and compared at 9 weeks after treatment. Results Bone density of the OVX group was significantly lower than the sham group (P<0.01), indicating that the rat OP model was successfully established. Like estrogen, CPCC inhibited the abnormal changes of all indices and maintain similar levels with those of the sham group (P>0.05), while the body weight gain of the E₂ group at weeks 8 and 9 was significantly lower than those of the sham group (P<0.01). As regarding the prevention of bone loss, the Mg and Ca levels of the E₂ group were significantly lower than those of the moderate and high dose CPCC groups. The Cu level was not significantly different compared with the sham group,while those in the moderate and low dose CPCC groups were significantly higher than the sham group. The Mn, Zn and hydroxyproline levels of the E₂ group were significantly lower than those of the sham group, while the CPCC group maintained levels similar to that of the sham group. In regarding to the inhibiting effect on the increased blood BGP and StrACP, the E₂ group was still maintained at levels similar to that of the OVX group, while those of the CPCC group were significantly lower than the OVX group. As regarding the decreased blood Ca, the E₂ group was not significantly different with that of the OVX group, while that of the CPCC group was significantly higher than the OVX group. Conclusions CPCC is more effective than estrogen in ameliorating the bone quality of ovariectomized rats.

Abstract:Objective To study the expression and significance of apoptosis-related genes caspase-3, caspase-9, Bax and Bcl-2 in oral normal mucosa, oral simple hyperplasia, oral epithelial dysplasia and oral squamous cell carcinomas (OSCC) in Chinese hamsters. Methods The expressions of mRNA and protein of caspase-3, caspase-9, Bax and Bcl-2 in the oral normal mucosa, oral simple hyperplasia, oral epithelial dysplasia and OSCC tissues in Chinese hamsters were examined by immunohistochemistry and RT-PCR. Results During the process of oral carcinogenesis, the expression of Bcl-2 protein was significantly higher in OSCC than in oral normal mucosa, oral simple hyperplasia, and oral epithelial dysplasia (P<0.05). In dysplastic epithelia, the protein expressions of caspase-3, caspase-9 and Bax were more than that of normal epithelia, and along with the increased dysplasis, the expression level was decreased. Further analysis showed that expression of Bcl-2 was negatively related with the expressions of Bax, caspase-3 and caspase-9 (P<0.05). The result of RT-PCR showed that Bcl-2 was significantly increased in OSCC compared with normal mucosa, while the expressions of caspase-3, caspase-9 and Bax were decreased (P<0.05). Conclusions In the Chinese hamster squamous carcinoma, the expressions of caspase-3, caspase-9 and Bax are reduced and the Bcl-2 expression are increased, indicating that the expressions of caspase-3, caspase-9, Bax and Bcl-2 are closely related with the occurrence and development of oral squamous cell cancinoma. This study can offer some clues for gene therapy of OSCC, or can provide a reference for evaluating the biological characteristics and prognosis of OSCC.

Abstract:Objective To investigate the effects of Roux-en-Y gastric bypass (RYGB) on hepatic and peripheral insulin sensitivity in rats with type 2 diabetes and their possible mechanisms. Methods 5-6 week old SPF male Sprague-Dawley rats were divided into 2 groups:diabetic RYGB group (n=21) and diabetic RYGB sham group (n=7). The hyperinsulinemic-euglycemic clamp with tracer infusion was completed at 2, 4, and 8 weeks postoperatively to assess the insulin sensitivity. The lipid content in liver and muscle tissue was examined. Results Postoperatively, the diabetic RYGB group had significant decreases in weight, fat mass, and RYGB had a profound effect on the plasma lipid profile. Two weeks after surgery, the hepatic insulin sensitivity index was significantly improved and the hepatic triglyceride was decreased in the RYGB group (P<0.05). The significant increased insulin sensitivity was not detected until four weeks after RYGB surgery, the M value was significantly increased and the TG content in the muscle tissue was significantly decreased (P<0.05). Conclusions The increased insulin sensitivity after RYGB occurs earlier in the liver than in the muscle and both may contribute to the long-term remission of type 2 diabetes. Reduced lipid content in hepatocytes and skeletal muscle cells after RYGB may contribute to the improved insulin sensitivity in these cells.

Abstract:Objective To establish an improved model of exercise-induced glycometabolism in type Ⅱ diabetic rats, and to provide a theoretical reference for the establishment of exercise prescription for type Ⅱ diabetes. Methods Forty-five 8-week old SPF male Wistar rats were used in this study. Of which 32 were fed with high-fat diet for 7 weeks, and intraperitoneal injection of 30 mg/kg STZ was given to establish the rat model of type Ⅱ diabetes.The normal rats and successful model rats were divided into four groups:The normal control group (C group),normal exercise group (CE group),diabetic group (DM group) and diabetic exercise group (DME group).The exercise group was assigned by the Ploug training protocol, 6 days/week, 60 min/day, for a total of 8 weeks.After the high fat diet fed for 7 weeks, blood sample was taken from the tail vein,FBG and serum insulin were detected after baseline and 8 weeks exercise, and blood sample was collected from the tail vein to determine the FBG. Serum insulin (FINS) was detected by orbital blood sampling at the end of 8 weeks of exercise, and HOMA-IR was calculated. Results 1.After 7 weeks of high fat diet,compared with the groups C and CE, the levels of FBG, FINS and HOMA-IR were significantly higher in the DM and DME groups.2. After 8 weeks of exercise intervention, compared with the groups C and CE,FINS was significantly lower in the groups DM and DME, but the FBG and HOMA-IR were higher. Compared with the DM group, the level of FINS was significantly higher in the DME group, and the levels of FBG and HOMA-IR were significantly lower.The body weights of DM and DME groups were significantly lower than those of the groups Cand CE,the body weight had no significant difference between the DME and DM groups, and similar result was between the groups CE and C. Conclusions 1.The rat model of type Ⅱ diabetes is successfully established with high fat diet for 7 weeks plus STZ injection(30 mg/mL). 2.Aerobic exercise 60 min/day for a total of 8 weeks can improve the glycometabolism in type 2 diabetic rats,to be an ideal animal model for study of the mechanism of prevention and amelioration of type Ⅱ diabetes.

Abstract:Objective To evaluate the effects of telmisartan by SOCS-3/SREBP-1c pathway and its efficacy of improving insulin resistance (IR) in rats with high-fat diet-induced nonalcoholic steatohepatitis (NASH). Methods A total of 70 SD male rats were assigned randomly into 3 groups:A (normal control, 20 rats, basic diet), B (model control, 30 rats, high-fat diet) and C (treatment with telmisartan, 20 rats, high-fat diet). After the IR-NASH model was made successfully, proved by 10 rats randomly from the group B with euglycemic hyperinsulinemic clamp technique (EHCT) and liver histology, the rats in the group C were intragastrically administrated telmisartan (5 mg/kg/d) for 4 weeks, and then all rats were tested with EHCT and sacrificed to test the blood chemistry, interleukin-6, homeostasis model assessment of insulin resistance, hepatic pathological analysis, and semiquantitative RT-PCR for determining SOCS-3 and SREBP-1c mRNA. Results Rats with high-fat diet developed steatohepatitis and insulin resistance at the 12th week and had more weight gain and higher liver index at the 16th week. IL-6, SOCS-3 and SREBP-1c mRNA expressions in the group B were up-regulated obviously, and each was positively correlated with the velocities of glucose infusion rates at 60~120 min. Blood chemistry and pathological observation in the group C were all improved; both SOCS-3 and SREBP-1c mRNA were down-regulated, and each negatively correlated with VGIR60-120, while serum IL-6 stayed at a high level. Conclusions Telmisartan can remarkably improve hepatic function and insulin resistance in rats with IR-NASH, the mechanisms of which would not be by path of reducing the secretion of IL-6, but by down-regulating the expressions of SOCS-3 and SREBP-1c mRNA.

Abstract:Objective To explore the effects of telmisartan on expression of peroxisome proliferators PPARs activated receptors and adiponectin receptor 2 in rats with nonalcoholic steatohepatitis (NASH). Methods Forty male SD rats were randomized into normal-diet control group (NC, n=15), high fat-diet control group (FC, n=15), and high fat-diet with telmisartan group (FT, n=10). NC group was given standard diet and the other two groups were given high-fat diet.At the end of the 12th week, 5 rats which were randomly selected from both the NC and FC groups were given euglycermic hyperinsulinemia clamp to see if fat-liver model of rats with insulin resistance was successfully induced, and rat livers were removed for pathological examination to determine the extents of NASH. Afterwards, rats in the FT group was given telmisartan (5 mg/kg·d) while rats in both the NC and FC groups were given the same volume of 0.9% saline solution by intragastric gavage for another 4 weeks.After glucose infusion rates (GIRs) were obtained by the euglycermic hyperinsulinemia clamp technique at the end of the 16th week, all rats were sacrificed and the body weight was recorded, and serum lipids, aminotransferases and fasting blood glucose were measured. The mRNA expressions of peroxisome proliferator activated receptors (PPARs), adiponectin receptor-2 and angiotensin Ⅱ type-1 receptor in the liver tissue were assessed by semi-quantitative reverse transcriptase polymerase chain reactions. Results The expressions of PPARα, PPARγ and AdipoR2 mRNA in the liver tissue of FC group were decreased significantly compared with the NC group (P<0.01), and the expression of AT1R mRNA of the liver tissue in FC group was increased significantly compared with NC group (P<0.01). Compared with the FC group, the expressions of PPARα, PPARγ and AdipoR2 mRNA in the FT group were increased (P<0.01).Serum aminotransferases, lipids and fasting blood glucose level in the rats of FC group were increased significantly compared with rats of the NC group (P<0.01), and serum aminotransferases, lipids and fasting blood glucose level in the rats of FT group were greatly improved compared with the FC group. Conclusions Telmisartan can improve glucose and lipid metabolism, stop weight gain, decrease liver index, and alleviate steatosis and inflammation of NASH rats by improving insulin resistance. Telmisartan may play an effective role in the protection of rat liver with NASH.

Abstract:Objective To observe and compare the function of peripheral blood derived dendritic cells (DC) in white hair black eyes (WHBE) rabbits and Japanese white (JW) rabbits with allergic rhinitis (AR) induced by ovalbumin (OVA), and to explore the mechanism of sensitivity to allergen in WHBE rabbits. Methods For the AR induction, rabbits were sensitized intraperitoneally everyday with OVA emulsified in Al(OH)₃ followed from day 17 onward by 5 times nasal challenges with OVA in each nostril. General symptoms and histopathological changes of the nasal mucosa were observed. Expressions of CD86 on cell surface and antigen uptake of peripheral blood-derived dendritic cells were detected by flow cytometry at 6 days of culture. The mannose receptor (MR) mRNA expression was tested by real-time PCR. Proliferation of CFSE -labelled T cells stimulated by DC were observed by flow cytometry. Results The rabbits sensitized by OVA showed typical AR symptoms and pathological changes.Expressions of CD86 on the cell surface of dendritic cells in WHBE rabbits with AR were significantly upregulated not only compared with the normal control (NC) rabbits, but also with the JW rabbits with AR (P<0.01). The result of real-time PCR assay showed that MR mRNA expression of DC in the NC group of WHBE rabbits were significantly higher than that of the JWrabbits(P<0.01). Moreover, MR mRNA expression of DCs in the WHBE rabbits with AR were not only significantly higher than that in the NC rabbits (P<0.05), but also higher than that in the JW rabbits with AR (P<0.05).Meanwhile, OVA₆₄₇ internalization percentages of DCs in the WHBE rabbits with AR were not only significantly higher than that in the NC rabbits, but also obviously higher than that in the JW rabbits with AR (P<0.01). Conclusions The sensitivity of WHBE rabbits to allergen may largely depend on the function of dendritic cells with high expression of mannose receptor and their strong ability of maturation and antigen uptake.

Abstract:Objective To establish a mouse model of circulating tumor cells (CTCs) by applying mouse hepatoma Hapa 1-6 cells. Methods 108 healthy male C57BL/6 mice were randomly divided into 3 groups according to their body weights. Hepa 1-6 cell suspension was intravenously injected to each mouse in the three groups at a concentration of 1×10⁶, 5×10⁶ and 1×10⁷/mL, 0.2 mL per mouse, respectively. Blood samples were collected from the mice on the 1st, 5th, 9th, 13th, 17th and 21st days after tumor cell injection. The number, ratio and relative inhibition rate of CTCs were calculated in 20,000 nucleated cells. The mortality of mice was recorded. ②80 male C57BL/6 mice were averaged into 2 groups according to their body weight:control and sorafenib tosylate groups.0.2 mL of Hepa 1-6 single cell suspension was injected to each mouse through the caudal vein at a concentration of 5×10⁶/mL. The mice were gavaged with sorafenib tosylate (50 mg/kg) for 21 days and blood samples were collected at the 3rd, 8th, 15th, and 21st days for CTC assessment. Results For the 1×10⁶/mL group, the CTC inhibition rate was 25.1%, 18.1%, 8.9%, 4.4%, 2.9% and 0.3% on the 1st, 5th, 9th, 13th, 17th and 21st days, respectively, and all the mice were alive. For the 5×10⁶/mL group, the CTC inhibition rate was 40.4%, 35.4%, 15.4%, 9.0%, 6.6% and 4.1% on the 1st, 5th, 9th, 13th, 17th and 21st days, respectively, and all the mice were alive. For the 1×10⁷/mL group, the CTC inhibition rate was 39.1% and 33.5% on the 1st and 5th days, respectively. Some mice died immediately after intravenous injection and all mice died within 7 days. ②The relative clearance of CTCs was -7.5%, 4.6%, 55.3% and -94.5% on the 3rd, 8th, 15th and 21st days of sorafenib tosylate administration. Compared with the control group, there were significant differences among the three groups (P<0.05 or P<0.01). Conclusions A mouse model of circulating hepatoma cells has been established by intravenous injection of 0.2 mL of 5×10⁶/mL mouse Hepa 1-6 cell suspension. This mouse model can be used for screening and evaluation of drugs for circulating tumor cell inhibition.

Abstract:Objective To establish a mouse model of diethylnitrosamine(DEN)-induced hepatocellular carcinoma (HCC), and to explore the effects of two different diet formulas on the establishment of DEN-induced HCC model. Methods SPF C57BL/6 mice (8 males and 8 females) were injected intraperitoneally with 25 mg/kg DEN at day 14 to establish a HCC model. The mice were divided into two groups after weaning. One group was fed with the SPF class rodents cereal-based diet, another group was fed with AIN-93G formula diet. The mice were sacrificed at the age of 9 months. The livers were weighed and the growth of liver cancer was observed and recorded. Results All the mice in the cereal-based diet group developed HCC as expected. The body weight and liver mass of the mice in the AIN-93G diet group were significantly lower than that of the cereal-based diet group. The incidence of HCC, and the number and size of tumor nodules were also significantly lower in the AIN-93G diet group than that in the cereal-based diet group. Conclusions DEN-induced HCC model has been successfully established in mice fed with cereal-based diet, while mice fed with AIN93-G diet prevented the development of DEN-induced HCC, and their body weight was decreased significantly, suggesting that dietary factors play a key role in establishment of animal disease models.

Abstract:Objective To establish animal models of functional dyspepsia with spleen deficiency and to compare the efficacy of different methods. Methods Rat models were established by iodoacetamide(IA)-treatment or combined with swimming.Appearance,body weight,food intake of the rats were observed,and serum motilin,cholecystokinin,lactate,gastrin content and urinary D-xylose excretion rates were detected to confirm whether the model of functional dyspepsia with spleen deficiency was established. Results The IA-treated rats had less food intake and a slower body weight gain.The IA-treated combined with swimming rats presented spleen-hypofunction symptoms,such as emaciation,hair dry and loose stools, their urinary D-xylose excretion rate, serum motilin, gastrin content were decreased, and serum cholecystokinin and lactate contents were increased significantly (P<0.05 for all). Conclusions All the three methods used in this study can result in symptoms of functional dyspepsia with spleen deficiency.However,IA-treatment combined with swimming models appear more close to spleen deficiency-like presentation, and the best model is the IA-treated combined with platform standing.

Abstract:Objective To study the effect of maca extract on sport fatigue and its antioxidant effect. Methods 50 healthy male Wistar rats were randomly divided into control group (normal breeding, without swimming, equal amount of distilled water for gavage), simple swimming group (swimming, equal amount of distilled water for gavage), swimming and medicine group (divided into maca extract 4.0, 8.0 and 16.0 g/(kg· bw) groups, respectively), 10 rats in each group. All rats were freely swimming in the circulating water flow daily for 15 days. On the 16th day of experiment, liver tissue samples were collected. The liver lipid peroxide (LPO),superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and liver glycogen level were determined. Results When rats were administered with maca extract at the doses of 4.0, 8.0, 16.0 g/(kg· bw), respectively, the swimming time before sinking and the total swimming time were increased by 18.99%, 64.46% and 90.69%, and 18.99%, 56.23% and 94.72%, respectively, while the numbers of times of sinking were decreased by 27.44%, 42.86%, 64.11% (P<0.01), respectively, compared with the swimming rats without maca extract treatment. The LPO content in the liver of rats treated with maca extract 4.0, 8.0, 16.0 g/(kg· bw) were reduced by 31.31%, 42.00% and 31.31%, respectively, while the levels of SOD, GSH-Px and liver glycogen were enhanced by 25.92%, 31.82%, 62.09%, 12.33%, 23.01%, 46.36% and 17.83%,44.69%, 62.99%,respectively, over those of rats without maca extract treatment. Conclusions Maca extract reduces the liver LPO level, increases liver glycogen level, improves the SOD and GSH-Px activity, therefore, plays a protective role in sport fatigue.

Abstract:Objective To investigate the relationship of vitamin D with the intestinal development and study the expression of vitamin D receptor (VDR) in the duodenum of C57BL/6 mice at different developmental stages. Methods Quantitative PCR (qPCR), histology using H&E staining and immunofluorescence staining, and Western blotting (WB) were performed to elucidate the expression of VDR in mice intestine at different growth and developmental stages. Results The peak of VDR mRNA expression reached on 21 d. The pathological result showed that VDR mainly distributed in the cytoplasm of epithelial cells and smooth muscle cells in the mouse duodenum. WB result indicated that there was no nuclear translocation of VDR protein in the mouse duodenum. Conclusions This study demonstrates the regularity of expression of VDR in the mouse duodenum during its development, and contributes to understanding the function of VDR in the intestines.

Abstract:Objective Ovariectomized rats are the most suitable model for the study of postmenopausal osteoporosis. However, the effect of ovariectomy on rat skin is little studied. The aim of this study was to observe the effect of ovariectomy on the skin aging indexes in rats. Methods 20 healthy 3-month-old female SD rats were randomly divided into sham group and ovariectomized (OVX) group. Serum estradiol was detected at 3 months after ovariectomy, the skin aging-related biochemical indexes such as catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) activity and the content of malondialdehyde (MDA), hydroxyproline (HYP) and lipofuscin (LF) were also detected. The structure of skin tissue was observed and detected using a pathological image analysis system. Results The serum E₂ of OVX rats was significantly lower than that in the sham group, the thickness of epidermis and dermis of OVX group was significantly thinner than that of the sham group (P<0.01), the amount of collagen fibers was decreased and their arrangement was very loose. Compared with the sham group, the activity of CAT, GSH-Px and SOD in the OVX group was significantly decreased (P<0.01), and the content of MDA was significantly increased (P<0.01). The content of HYP in skin tissue was significantly decreased, and LF content was significantly increased (P<0.01) in the OVX group. Conclusions Skin aging can be induced at 3 months after ovariectomy in 3-month old rats, which may be a good model for the study of skin aging in postmenopausal women.

Abstract:Genetically modified tool animal models are the animal models, which are generated by modifying a defined gene and can be used as a tool to help realize other objective. Genetically modified large animals have wide applications in agriculture and biomedicine. Tool animal models play important role in biological research and development of new drugs in biomedicine,especially, have made tremendous contribution in revealing gene function and pathway of signal transduction.Pigs are not only an economically important agriculture animals, but also an ideal animal model in biomedicine due to its close similarity to human in physiology, as well as organ structure and size.Thanks to the breakthrough of newly emerged gene editing technology,striking progress has made in establishment of genetically modified tool pig models which include the ones used for monitoring pluripotency of cells, tracing cell lineages, replacing genes mediated by Cre recombinase, mimicking immunodeficiency,as well as gene editing in vivo.These tool models have been widely applied in biological research.Here, we will review the progress in generation of genetically modified tool pig models and their applications.

Abstract:The risk factors of diastolic heart failure include among others:hypertension, diabetes, myocardial ischemia and aging. The underlying mechanisms for this cardiac complication are incompletely understood. With the increase of aging of the population, the prevalence and mortality of diastolic heart failure is rising gradually. It seriously affects the life quality and life span of people. In order to more truly reveal the underlying mechanisms of diastolic heart failure and to develope novel therapeutic strategies, the experimental animal models are extremely important. The present review focuses on providing an overview of the characteristics of these models for the growing number of investigators who seek to understand the pathology of diastolic heart failure.

Abstract:Attentional set-shifting tasks are used as a measure of human fronto-executive function. the cognitive processes involved in forming an attentional set, maintaining an attentional set and shifting an attentional set are vulnerable to dysfunction arising from a number of human neurological disorders (such as attentional deficit/hyperactivity disorder, depression, schizophrenia) and neurodegenerative diseases (such as Parkinson's, Huntington's, Alzheimer's diseases). Recently, researches on rodents mainly continue to illustrate normal rats which are caused by different operating different performance in the attentional set-shifting tasks. And also there are few studies committed to observe the adaptability of the rats in attentional set-shifting tasks as well as different performance between species of rodents in attentional set shifting tasks. In addition, these results have elucidated the roles of multiple neurotransmitters in the manifestation of cognitive processes. This review focuses on the methodology of the attentional set-shifting tasks and the role of the neurotransmitter in cognitive processes.