不同负荷训练对小白鼠胫骨前肌肌纤维型和运动终板影响的组织化学研究

本文用SDH-AchE结合法染色,光镜下观察了不同负荷训练的小白鼠胫骨前肌的肌纤维型和运动终板的变化。本研究证明:间歇跑训练组的红肌纤维数量明显减少,自肌纤维及中间肌纤维数量明显增多;连续跑训练的白肌纤维数量明显减少,中间肌纤维数量明显增多,红肌纤维数量无明显改变。雄性鼠三型肌纤维的平均直径训练组与对照组相比呈一致性显著增加;雌性鼠三型肌纤维的平均直径:连续跑组与对照组相比显著增加,间歇跑组与对照组相比显著减少。三型肌纤维上的运动终板数量百分比无明显改变。本文就观察结果讨论了这些变化的生理意义。

Correlation between TIMP-1 expression and liver fibrosis in two rat liver fibrosis models

AIM： To evaluate serum TIMP-1 level and the correlation between TIMP-1 expression and liver fibrosis in immuneinduced and CCL4-induced liver fibrosis models in rats. METHODS： Immune-induced and CCL4-induced liver fibrosis models were established by dexamethasone （0.01 mg） and CCL4 respectively. Serum TIMP-1 level was detected with ELISA, while histopathological grade of liver biopsy was evaluated. Spearman rankcorrelation test was used to analyse the difference of the correlation between the TIMP-1 expression and hepatic fibrosis in the two fibrosis models. Furthermore,in situ hybridization was used to determine the expression difference of TIMP-1 mRNA in the two models. RESULTS： Positive correlation existed between serum TIMP-1 level of immune induced group and the histopathological stages of fibrosis liver of corresponding rats （Spearman rank-correlation test, rs = 0.812, P 0.05）, and the positive in situ hybridization signal of TIMP-1 mRNA was strong. In CCL4-induced liver fibrosis model, the correlation between the serum TIMP-1 level and the severity of hepatic fibrosis was not statistically significant（Spearman rank-correlation test, rs = 0.229, P 〉 0.05）. And compared with immune-induced model, the positivein situ hybridization signal of TIMP-1 mRNA was weaker, while the expression variation was higher in hepatic fibrosis of the same severity. CONCLUSION： The correlations between TIMP-1 expression and liver fibrosis in two rat liver fibrosis models are different. In immune-induced model, serum TIMP-1 level could reflect the severity of liver fibrosis, while in CCL4-induced model, the correlation between the serum TIMP-1 level and the severity of hepatic fibrosis was not statistically significant.

TypeⅠinositol 1, 4, 5-triphosphate receptors increase in kidney of mice with fulminant hepatic failure

AIM： To delineate the mechanisms of renal vasoconstriction in hepatorenal syndrome （HRS）, we investigated the expression of type I inositol 1, 4, 5-triphosphate receptors （IP3R I） of kidney in mice with fulminant hepatic failure （FHF）. METHODS： FHF was induced by lipopolysaccharide （LPS） in D-galactosamine （GAIN） sensitized BALB/c mice. There were 20 mice in normal saline （NS）-treated group, 20 mice in LPS-treated group, 20 mice in GaIN- treated group, and 60 mice in GalN/LPS-treated group （FHF group）. Liver and kidney tissues were obtained at 2, 6, and 9 h after administration. The liver and kidney specimens were stained with hematoxylin-eosin for studying morphological changes under light microscope. The expression of IP3R I in kidney tissue was tested by immunohistochemistry, Western blot and reverse transcription （RT）-PCR. RESULTS： Kidney tissues were morphologically normal at all time points in all groups. IP3R I proteins were found localized in the plasma region of glomerular mesangial cells （GMC） and vascular smooth muscle cells （VSMC） in kidney by immunohistochemical staining. In kidney of mice with FHF at 6 h and 9 h IP3R I staining was upregulated. Results from Western blot demonstrated consistent and significant increment of IP3R I expression in mice with FHF at 6 h and 9 h （t = 3.16, P 〈 0.05; t = 5.43, P 〈 0.01）. Furthermore, we evaluated IP3R I mRNA expression by RT-PCR and observed marked upregulation of IP3R I mRNA in FHF samples at 2 h, 6 h and 9 h compared to controls （t = 2.97, P 〈 0.05; t = 4.42, P 〈 0.01; t = 3.81, P 〈 0.01）. CONCLUSION： The expression of IP3R I protein increased in GMC and renal VSMC of mice with FHF, possibly caused by up-regulation of IP3R I mRNA.

Smad3 knock-out mice as a useful model to study intestinal fibrogenesis

AIM： To evaluate the possible differences in morphology and immunohistochemical expression of CD3, transforming growth factor 131（TGF-131）, Smad7, α-smooth muscle actin （α-Sma）, and collagen types Ⅰ-Ⅶ of small and large intestine in Smad3 null and wild-type mice. METHODS： Ten null and ten wild-type adult mice were sacrificed at 4 mo of age and the organs （esophagus, small and large bowel, ureters） were collected for histology（hematoxylin and eosin, Masson thrichrome, silver staining）, morphometry and immunohistochemistry analysis. TGF-β1 levels of intestinal tissue homogenates were assessed by ELISA. RESULTS： No macroscopic intestinal lesions were detected both in null and wild-type mice. Histological and morphometric evaluation revealed a significant reduction in muscle layer thickness of small and large intestine in null mice as compared to wild-type mice. Immunohistochemistry evaluation showed a significant increase of CD3＋T cell, TGF-β1 and Smad7 staining in the small and large intestine mucosa of Smad3 null mice as compared to wild-type mice. α-Sma and collagen Ⅰ-Ⅶ staining of small and large intestine did not differ between the two groups of mice. TGF-β1 levels of colonic tissue homogenates were significantly higher in null mice than in wildtype mice. In preliminary experiments a significant reduction of TNBS-induced intestinal fibrosis was observed in null mice as compared to wild-type mice.

Fibrinogen deficiency suppresses the development of early and delayed radiation enteropathy

To determine the mechanistic role of fibrinogen, a key regulator of inflammation and fibrosis, in early and delayed radiation enteropathy. METHODSFibrinogen wild-type (Fib+/+), fibrinogen heterozygous (Fib+/-), and fibrinogen knockout (Fib-/-) mice were exposed to localized intestinal irradiation and assessed for early and delayed structural changes in the intestinal tissue. A 5-cm segment of ileum of mice was exteriorized and exposed to 18.5 Gy of x-irradiation. Intestinal tissue injury was assessed by quantitative histology, morphometry, and immunohistochemistry at 2 wk and 26 wk after radiation. Plasma fibrinogen level was measured by enzyme-linked immunosorbent assay. RESULTSThere was no difference between sham-irradiated Fib+/+ and Fib+/- mice in terms of fibrinogen concentration in plasma and intestinal tissue, intestinal histology, morphometry, intestinal smooth muscle cell proliferation, and neutrophil infiltration. Therefore, Fib+/- mice were used as littermate controls. Unlike sham-irradiated Fib+/+ and Fib+/- mice, no fibrinogen was detected in the plasma and intestinal tissue of sham-irradiated Fib-/- mice. Moreover, fibrinogen level was not elevated after irradiation in the intestinal tissue of Fib-/- mice, while significant increase in intestinal fibrinogen level was noticed in irradiated Fib+/+ and Fib+/- mice. Importantly, irradiated Fib-/- mice exhibited substantially less overall intestinal structural injury (RIS, P = 0.000002), intestinal wall thickness (P = 0.003), intestinal serosal thickness (P = 0.009), collagen deposition (P = 0.01), TGF-β immunoreactivity (P = 0.03), intestinal smooth muscle proliferation (P = 0.046), neutrophil infiltration (P = 0.01), and intestinal mucosal injury (P = 0.0003), compared to irradiated Fib+/+ and Fib+/- mice at both 2 wk and 26 wk. CONCLUSIONThese data demonstrate that fibrinogen deficiency directly attenuates development of early and delayed radiation enteropathy. Fibrinogen could be a novel target in treating intestinal damage.

Tetrandrine stimulates the apoptosis of hepatic stellate cells and ameliorates development of fibrosis in a thioacetamide rat model

AIM： To investigate the therapeutic effect of tetrandrine on liver fibrosis induced by thioacetamide in rats in vivo and in vitro. METHODS： In vitro study： we investigated the effect of tetrandrine on the apoptosis of rat hepatic stellate cells transformed by simian virus 40 （T-HSC/CI-6）, which retains the features of activated cells. In vivo study： hepatic fibrosis was induced in rats by thioacetamide. Tetrandrine was given orally to rats at doses of 5, 10 or 20 mg/kg for 4 wk compared with intraperitoneal injection of interferon-r. RESULTS： In vitro study： 5, 10 or 25 μg/mL of tetrandrine-induced activation of caspase-3 in t-HSC/CI-6 cells occurred dose-dependently. In vivo study： tetrandrine treatment as well as interferon-r significantly ameliorated the development of fibrosis as determined by lowered serum levels of aspartate aminotransferase （AST）, alanine aminotransferase （ALT）, total bilirubin （T-Bil） and the levels of liver hydroxyproline （Hyp）, hyaluronic acid （HA）, laminin （LN） and also improved histological findings. The effects of tetrandrine at the concentration of 20 mg/kg were better than the other concentration groups. CONCLUSION： Tetrandrine promotes the apoptosis of activated HSCs in vitro. Tetrandrine administration can prevent liver fibrosis and liver damage induced by thioacetamide in rats in vivo, indicating that it might exert a direct effect on rat HSCs.

In vivo effects of Chinese herbal recipe, Danshaohuaxian, on apoptosis and proliferation of hepatic stellate cells in hepatic fibrotic rats

AIM: To investigate the effects of Danshaohuaxian (DSHX), a Chinese herbal recipe, on the apoptosis and cell cycles of hepatic stellate cells (HSCs) in rat hepatic fibrosis and its possible mechanisms. METHODS: Seventy-six male Wistar rats were randomly divided into normal control group, hepatic fibrosis group, non-DSHX-treated group and DSHX-treated group. Except for the normal control group, rat hepatic fibrotic models were induced by subcutaneous injection of carbon tetrachloride (CCl4), drinking alcohol, giving diet of hyperlipid and hypoprotein for 8 wk. When the hepatic fibrotic models were produced, 12 rats of hepatic fibrosis group (15 rats survived, others died during the 8 wk) were sacrificed to collect blood and livers. HSCs were isolated from the other 3 rats to detect the apoptotic index (AI) and cell cycles by flow cytometry. DSHX was then given to the DSHX-treated group (1.0 g/kg, PO, daily) for 8 wk. At the same time, normal control group and non-DSHX-treated group were given normal saline for 8 wk. At end of the experiment, some rats in these three groups were sacrificed to collect blood and livers, the other rats were used for HSC isolation to detect the apoptotic index (AI) and cell cycles. Then the liver index, serum hyaluronic acid (HA) and alanine aminotransferase (ALT), degree of hepatic fibrosis, urinary excretion of hydroxyproline (Hyp) and expression of collagen types Ⅰ and Ⅲ (COL Ⅰ and Ⅲ) in these four groups were detected respectively. RESULTS: Compared with the indexes of the hepatic fibrosis group and non-DSHX-treated group, the DSHX-treated group revealed a liver index of (0.0267±0.0017 vs 0.0423±0.0044, 0.0295±0.0019, P<0.05), levels of serum HA (200.78±31.71 vs 316.17±78.48, 300.86±72.73, P<0.05) and ALT(93.13±5.79 vs 174.5±6.02, 104.75±6.54, P<0.01), and stage of hepatic fibrosis (1.30 vs 4.25, 2.60, P<0.01) all reduced. The urinary excretion of Hyp increased (541.09±73.39 vs 62.00±6.40, 182.44±30.83, P<0.01), the COL Ⅰ and Ⅲ expression decreased (COL I: 1.07±0.96 vs 4.18±2.26, 3.22±1.44, P<0.01; COL Ⅲ: 1.09±0.58 vs 3.04±0.62, 2.23±0.58, P<0.01), the HSCs apoptotic index of HSCs (7.81±0.47 vs 1.63±0.25, 1.78±0.4, P<0.05) and the ratio of G0-G1 phase cells increased (94.30±1.33 vs 62.27±17.96, 50.53±2.25, P<0.05). The ratios of S-phase cells (3.11±1.27 vs 9.83±1.81, 11.87±1.9, P<0.05) and G2-M phase cells (2.58±0.73 vs 23.26±10.95, 13.60±1.15, P<0.01) declined. CONCLUSION: DSHX capsule shows certain therapeutic effects on hepatic fibrosis in rats and inhibits abnormal deposition of COL I and III in rat livers by promoting the apoptosis of HSCs and preventing their proliferation.

Potential application of neogalactosylalbumin in positron emission tomography evaluation of liver function

AIM To investigate the evaluation of neogalactosylalbumin (NGA) for liver function assessment based on positron emission tomography technology. METHODS Female Kunming mice were assigned randomly to two groups: fibrosis group and normal control group. A murine hepatic fibrosis model was generated by intraperitoneal injection of 10% carbon tetrachloride (CCl4) at 0.4 ml every 48 h for 42 d. F-18-labeled NGA ([F-18] FNGA) was synthesized and administered at a dosage of 3.7 MBq/mouse to both fibrosis mice and normal control mice. Distribution of [F-18] FNGA amongst organs was examined, and dynamic scanning was performed. Parameters were set up to compare the uptake of tracers by fibrotic liver and healthy liver. Serologic tests for liver function were also performed. RESULTS The liver function of the fibrosis model mice was significantly impaired by the use of CCl4. In the fibrosis model mice, hepatic fibrosis was verified by naked eye assessment and pathological analysis. [F-18] FNGA was found to predominantly accumulate in liver and kidneys in both control group (n = 21) and fibrosis group (n = 23). The liver uptake ability (LUA), peak time (T-p), and uptake rate (LUR) of [F-18] FNGA between healthy liver (n = 8) and fibrosis liver (n = 10) were significantly different (P < 0.05, < 0.01, and < 0.05, respectively). LUA was significantly correlated with total serum protein level (TP) (P < 0.05). T-p was significantly correlated with both TP and glucose (Glu) concentration (P < 0.05 both), and LUR was significantly correlated with both total bile acid and Glu concentration (P < 0.01 and < 0.05, respectively). CONCLUSION [F-18] FNGA mainly accumulated in liver and remained for sufficient time. Functionally-impaired liver showed a significant different uptake pattern of [F-18] FNGA compared to the controls.

Evaluation of cellular responses associated with subcutaneous implantation of dental porcelain in a rat model

Biocompatibility of dental porcelain is of crucial importance to the long-term success of dental prostheses because of its close contact with oral tissues for extended periods. This investigation was aimed to evaluate cellular responses to locally produced dental porcelain （Universiti Sains Malaysia, Malaysia） after a short-term subcutaneous implantation in a rat model. Locally produced dental porcelains supplied in disc form were implanted subcutaneously into 12 Sprague-Dawley male albino rats, which were sacrificed in groups of 3 at 1, 2, 3 and 4 weeks after implantation. A semi-quantitative histological analysis of the tissue surrounding implanted discs was done under an image analyzer after staining with hematoxyline and eosin. The macrophage was clearly the dominant cell type at the implant surface at the first week after implantation, followed by a gradual decrease as the implantation period increased. On the contrary, fibroblasts and fibrocytes were the dominant cell types in the tissue surrounding the implanted discs at the third and fourth week after implantation with the appearance of mature collagen. From pathological point of view, the disappearance of inflammatory cellular responses and the well matured fibrous connective tissue surrounding the implanted discs indicate a satisfactory in vivo biocompatibility.

Astragalus mongholicus ameliorates renal fibrosis by modulating HGF and TGF-β in rats with unilateral ureteral obstruction

Astragalus mongholicus （AM） derived from the dry root ofAstragalus membranaceus Bge. var. mongolicus （Bge.） Hsiao is a widely used traditional Chinese medicine. The present study investigated the potential role of AM on renal fibrosis on a rat model of unilateral ureteral obstruction （UUO）. We divided 48 Sprague-Dawley rats randomly into 4 groups： sham-operated group （Sham）, untreated UUO group, AM-treated （10 g/（kg.d）） UUO group, and losartan-treated （20 mg/（kg.d）） UUO group as positive control. Haematoxylin ＆ eosin （HE） and Masson staining were used to study the dynamic histological changes of the kidneys 7 and 14 d after operation. The expressions of fibronectin （FN）, type I collagen （coil）, hepatocyte growth factor （HGF）, transforming growth factor-β1 （TGF-β1）, and eL-smooth muscle actin （α-SMA） were analyzed by real-time polymerase chain reaction （PCR）, immunohistochemistry staining, and Western blot. Results show that, similar to losartan, AM alleviated the renal damage and decreased the deposition of FN and coil from UUO by reducing the expressions of TGF-β1 and α-SMA （P〈0.05）, whereas HGF increased greatly with AM treatment （P〈0.05）. Our findings reveal that AM could retard the progression of renal fibrosis. The renoprotective effect of AM might be related to inhibition ofmyofibroblast activation, inducing of HGF and reducing of TGF-β1 expression.

Collagen scaffolds modified with collagen-binding bFGF promotes the neural regeneration in a rat hemisected spinal cord injury model

Nerve conduit is one of strategies for spine cord injury(SCI)treatment.Recently,studies showed that biomaterials could guide the neurite growth and promote axon regeneration at the injury site.However,the scaffold by itself was difficult to meet the need of SCI functional recovery.The basic fibroblast growth factor(bFGF)administration significantly promotes functional recovery after organ injuries.Here,using a rat model of T9 hemisected SCI,we aimed at assessing the repair capacity of implantation of collagen scaffold(CS)modified by collagen binding bFGF(CBD-bFGF).The results showed that CS combined with CBD-bFGF treatment improved survival rates after the lateral hemisection SCI.The CS/CBD-bFGF group showed more significant improvements in motor than the simply CS-implanted and untreated control group,when evaluated by the 21-point Basso-Beattie-Bresnahan(BBB)score and footprint analysis.Both hematoxylin and eosin(H&E)and immunohistochemical staining of neurofilament(NF)and glial fibrillary acidic protein(GFAP)demonstrated that fibers were guided to grow through the implants.These findings indicated that administration of CS modified with CBD-bFGF could promote spinal cord regeneration and functional recovery.

Inhibition mechanism of compound ethanol extracts from Wuweizi(Fructus Schisandrae Chinensis) on renal interstitial fibrosis in diabetic nephropathy model mice

OBJECTIVE：To evaluate inhibition effect and mech- anism of compound ethanol extracts from Wuweizi （Fructus Schisandrae Chinensis）, Chuanxiong （Rhi- zoma Chuanxiong） and Muli （Cocha Ostreae） （FRC） on glomerular and tubular interstitial fibrosis in streptozocin （STZ）-induced diabetic nephropathy （ND） model mice. METHODS： Twenty-seven male C57BL/6 mice were divided randomly into 3 groups： nondibetic （ND）, STZ-induced diabetic （D）, and STZ-induced diabetic that were treated with .5 g. kg1. daylof FRC by oral gavage （DFRc）, with 9 in each group. The protein ex- pressions of E-cadherin, a-smooth muscle actin （a-SMA）, Plasminogen Activator Inhibitor-1 （PAl-l） in renal tissues were investigated by Western blot- ting. The expressions of fibronectin （FN） and o-SMA were detected by immunohistochemical method. The morphological changes of renal tissues were observed under a microscope. RESULTS： Renal tissues in the DFRC group showed a lessened degree of fibrosis. Meanwhile, the expres- sions of FN, o-SMA and PAl-lwere significantly lower in the DrRc group than those in the D group （all P〈0.05）.CONCLUSION： FRC can ameliorate the DN in the C57BL/6 mice, and its mechanism may relate to in- hibition on the epithelial to mesenchymal transdif- ferentiation, endothelial-myofibroblast transition and PAl-1 expression.