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Objective:To investigate the mechanism of crush syndrome (CS) induced by crush injury on myocardial cells in rats.Methods:Thirty two male Sprague Dawley (SD) rats were randomly divided into control group, CS-0 group, CS-12 group and CS-24 group with 8 rats in each group. CS model was made by self-made extruder and perfused with 4% paraformaldehyde for 0, 12 and 24 h. The morphological changes of myocardial tissue were observed by hematoxylin staining. The apoptosis of cardiomyocytes was detected by terminal dexynucleotide transferase-mediated nick end labeling (TUNEL). The levels and activities of malondialdehyde (MDA), superoxide dismutase (SOD), lactose dehydrogenase (LDH), interleukin-6 (IL-6), interleukin-1 β (IL-1 β), tumor necrosis factor-α (TNF- α) in myocardial homogenate were detected by enzyme-linked immunosorbent assay (ELISA). The expressions of Caspase-3, Bax, Bcl-2 and necrosis factor-κB (NF-κ B) were detected by Western blot.Results:Compared with the control group, the myocardial tissue of CS model group had different degrees of morphological damage; compared with the control group, the apoptosis rate, Caspase-3 and Bax protein expression levels of CS-0 group, CS-12 group and CS-24 group were significantly increased ( P<0.05), and the expression level of Bcl-2 protein was significantly decreased ( P<0.05); compared with the control group, the levels of MDA, LDH, IL-6, IL-1β, TNF-α and p65 protein phosphorylation in the myocardial homogenate of CS-0 group, CS-12 group and CS-24 group were significantly increased ( P<0.05), and SOD activity was significantly decreased ( P<0.05). Conclusions:CS may inhibit oxidative stress and induce inflammatory reaction by activating NF-κ B pathway, thus damaging myocardial cells in rats.
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Objective To explore the effect of NPY on activation of primary microglia and the production of in?terleukin-1β. Methods Rat primary cortical microglia was cultured and divided into control group, LPS group, NPY+LPS group, NPY group and BIBP3226+NPY+LPS group. Microglia in control group were incubated with serum-free me?dium for 6 h;microglia in LPS group were incubated with serum-free medium plus LPS for 6 h;microglia in NPY+LPS group were incubated with serum-free medium plus NPY and LPS for 6 h; microglia cells in NPY group were incubat?ed in serum-free medium plus NPY for 6 h; microglia cells in BIBP3226+NPY+LPS group were incubated in se?rum-free medium including BIBP3226 、NPY and LPS for 6 h. After 6 h , Primary cultured microglia were stained us?ing IBA-1 antibody and examined under the fluorescence microscope. The protein levels of IL-1βin the culture media and the mRNA expression levels of IL-1βin the microglia of different groups were detected using the methods of Elisa and RT-PCR. Results After 6 h, the contents of IL-1 βin the culture media and the mRNA expression levels of IL-1βin the cells of LPS group increased remarkably compared with control group (P<0.05) and the microglia were activat? ed. Compared with LPS group, the contents of IL-1 βin the culture media. the mRNA expression levels of IL-1β and the activity of microglia in LPS+NPY group were significantly decreased .Compared with LPS+NPY group, the contents of IL-1βin the culture media. the mRNA expression levels of IL-1β and the activity of microglia in BIBP3226+NPY+LPS group were increased (P<0.05). There were no significant differences in the contents of IL-1βin the culture media. the mRNA expression levels of IL-1βand the activity of microglia between BIBP3226+NPY+LPS group and LPS group or between NPY group and the control group. Conclusion NPY can inhibit the biological activity of microglia and IL-1βproduction through NPY Y1 receptorin the microglia.
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Objective To observe bone formation of compound of autologous periosteum cells plus calcium alginate gelatin in animal body and investigate the best mixing ratio of the two components.Methods A total of 96 healthy adult New Zealand rabbits were randomly divided into six groups (Groups A,B,C,D,E and control group).The excised bilateral periostea from rabbits in each experimental group were all made into 0.4 ml cell suspensions.The compounds were prepared by blending 0.4 ml calcium alginate gelatin with 1,1/4,1/16,1/64 and 1/256 of the periosteum cell suspension respectively,and then were applied to autologous right radial defect area.Gross observation,X-ray examination and histological study were carried out at 2,4,8,12 weeks postoperatively.Levels of serum alkaline phosphatase and serum calcium were determined as well.Results The compounds containing periosteum cell suspension with cell counts of 1/4 or 1/16 and calcium alginate gelatin reached the best osteogenesis.Conclusion Compound of autologous periosteum cell suspension-calcium alginate gelatin induces obvious bone formation and is worthy of clinical application,for it has advantages of satisfactory bone defect repair and easy operation.
