Effect of hyperbaric oxygen on HIF-1α expression in rat experimental periodontitis with psychological stress

AIM: To investigate the effect of hyperbaric oxygen (HBO) on hypoxia-inducible factor-1α (HIF-1α) expression in rat experimental periodontitis with psychological stress. METHODS: Male special pathogen-free Wistar rats (n=120) were randomly divided into 4 groups: normal control group; psychological stress stimulation group; experimental periodontitis group: the periodontitis model was induced by wrapping 3/0 silk ligature inoculated with Porphyromonas gingivalis around the left maxillary second molar of the rats; periodontitis model with stress stimulation group. Psychological stress was removed at the 9th weeks after ligature, 6 rats from each experiment group were randomly chosen to HBO treatment. The rats were sacrificed at the 2nd, 4th, 8th and 10th weeks after ligature. Gingival index (GI) and attachment loss (AL) were measured before sacrifice. The histological changes of periodontal tissues were observed under microscope with HE staining. The expression of HIF-1α was observed by the method of immunohistochemistry. RESULTS: The sites of gingival attachment were normal in control group and psychological stress stimulation group. Periodontal pocket, and periodontal attachment loss were observed in experimental periodontitis group. The tissue damage was much serious in periodontitis model with stress stimulation group. No significant difference of GI and AL among psychological stress stimulation group and normal control group during the experiment was observed. GI and AL in periodonitis model with stress stimulating group were significantly higher than those in experimental periodontitis group at the 4th and 8th weeks (P < 0.01). The levels of GI and AL were significantly lower at the 10th weeks after HBO treatmnt than those in untreated groups (P < 0.05). No significant difference of HIF-1α expression scores among psychological stress stimulation group and normal control group was found. HIF-1α expression scores in periodonitis model with stress stimulating group was significantly higher than that in experimental periodontitis group at the 4th and 8th weeks (P < 0.01). At the 10th weeks after HBO treatment the levels of HIF-1α were significantly lower than that in untreated groups (P < 0.01). CONCLUSION: Stress stimulation may aggravate periodontitis by decreasing tissue oxygenation in rats. HBO may represent a useful way in psychological stress periodontitis therapy.     

Effect of psychological stress on development of periodontitis and expression of periodontal hypoxia-inducible factor 1α in rats

AIM: To investigate the effect of psychological stress on the development of periodontitis and the expression of periodontal hypoxia-inducible factor 1α(HIF-1α) in rats.METHODS: Forty-eight male Wistar rats(SPF grade) were randomly divided into 4 groups:(1) normal control group, i.e. naive rats;(2) experimental periodontitis group: the periodontitis model was induced by wrapping 3-0 silk ligature inoculated with putative periodontopathic bacteria around the left maxillary second molar of the rats;(3) stress group: the rats were treated with stress alone;(4) periodontits with stress group, the periodontitis model was induced as above,and the rats were treated with stress. The rats were sacrificed at week 1, 4, 6 and 8 after the ligature. The attachment losses(AL) were measured by home-made probe. The histological changes of periodontal tissues stained with hematoxylin and eosin(HE) were observed under microscope. The HIF-1α expression level in the periodontal epithelium was determined by immunohistochemistry that was used to evaluate the severity of hypoxia by measuring the average rate of HIF-1α-positive cells.RESULTS: No significant difference of AL between stress group and normal control group was observed(P>0.05).The AL and the average rate of HIF-1α-positive cells in periodontitis with stress group were significantly higher than those in experimental periodontitis group at time points of week 4,6 and 8 after ligature(both P<0.01).CONCLUSION: Psychological stress is one of the periodontitis inducing factors in the animal model. Psychological stress may aggravate periodontitis by decreasing tissue oxygenation in rats.     

Influence of chronic psychological stress on periodontitis and serum isoenzyme LDH1 in rats

AIM: To investigate the role of chronic psychological stress on periodontitis and serum level of isoenzyme LDH1 in rats. METHODS: Eighty female special pathogen-free Wistar rats were randomly divided into 4 groups:(1) normal control group; (2) experimental periodontitis group: the periodontitis model was induced by wrapping 3/0 silk ligature inoculated with putative periodontopathic bacteria around the left maxillary second molar of the rats; (3) psychological stress stimulation group: the rats were treated with stress stimulation alone; (4) periodontitis model with stress stimulation group: the periodontitis models were induced by wrapping 3/0 silk ligature inoculated with putative periodontopathic bacteria around the left maxillary second molar of the rats, and then treated with stress stimulation. The rats were sacrificed at 2nd, 4th, 6th and 8th weeks after ligature. The levels of blood glucose and adrenocorticotropic hormone (ACTH) were measured as the stress markers, and the serum isoenzyme lactate dehydrogenase 1(LDH1) was used to evaluate the severity of hypoxia. The histological changes of periodontal tissues were observed under microscope with HE staining. RESULTS: The levels of blood glucose and ACTH in stress group and periodontitis with stress group were significantly higher than those in control group and experimental periodontitis group at the 2nd and 4th weeks after ligature (P<0.01). The level of serum LDH in periodontitis with stress group was significantly higher than that in control group. The level of serum LDH1 in periodontitis with stress group was significantly lower than that in control group (P<0.01). No difference of histological change in periodontal tissues was observed in control group and stress group. Severer inflammatory changes and alveolar bone destruction were observed in periodontitis with stress group than those in experimental periodontitis group. CONCLUSION: Stress stimulation is one of the inducing factors of periodontitis in rats that aggravates periodontitis by decreasing the tissue oxygenation.     

Effect of nimesulide on ligature-induced periodontitis in rats

AIM: The purpose of this study was to observe the effect of nimesulide on periodontitis. METHODS: The gingival index (GI) was measured before the rats were sacrificed at the ends of week 4, 5 and 8. The periodontal tissues were stained with hematoxylin and eosin. Histological changes were observed by microscope. The periodontal attachment loss (AL) was measured by Tiger cell image analyzer. RESULTS: (1) Experimental periodontitis was successfully induced in rats by placing a piece of 3/0 braided silk around the cervix of the lower incisors at week 4 after the ligature. (2) In ligature-induced periodontitis group, at week 4 after the ligature, the GI and AL were significantly higher than those in control group (P<0.01). The histopathologic changes of periodontium in periodontitis group showed obvious inflammation, and the severity of destruction for periodontium was increased as time passed. (3) In the nimesulide prevention group, the GI and AL were significantly lower than those in periodontitis group (P<0.01). The histopathologic examination showed less inflammatory responses, and no obvious alveolar bone resorption was observed. (4) In the nimesulide treatment group, the GI and AL were significantly lower than those in periodontitis group at the end of week 5 and 8 after the ligature (P<0.01).CONCLUSION: (1) In ligature-induced periodontitis, nimesulide inhibits effectively its progress. (2) In the developing periodontitis, a significant improvement is observed in GI and AL following the treatment with nimesulide.     

Effects of baicalin on serum levels of IL-6 and IL-4 in mouse periodontitis

AIM: To investigate the effect of baicalin on experimental periodontitis in mouse model by comparing the histological changes in periodontal tissues and serum levels of inter leukin(IL)-6/IL-4 in mice, and to analyze the role of baicalin in immune regulation and anti-inflammatory mechanisms. METHODS: Twenty-seven male Kunming mice (SPF grade, 12-week-old) were randomly divided into 3 groups. The naive mice were used in normal control group. In experimental periodontitis group, the periodontitis model was produced by ligature of braided silk around the first maxillary molar and inoculation with putative periodontopathic bacteria. Five weeks after the ligature, the mice were fed with 10% glucose, and gavaged with distilled water. In baicalin treatment+periodontitis group, the periodontitis model was induced as above, then gavaged with baicalin at the beginning of the fifth week after the ligature. The mice were sacrificed at week 4, 6 and 8. The histological changes of the periodontal tissues were observed under microscope with hematoxylin and eosin (HE) staining. The serum level of IL-6 and IL-4 in the mice were determined by ELISA. RESULTS: The periodontal tissues showed moderate inflammatory damages in experimental periodontitis group. The periodontal destruction was significantly reduced in baicalin treatment+periodontitis group. The serum level of IL-6 in experimental periodontitis group was significantly higher than that in control group and baicalin treatment+periodontitis group (P<0.01), and the serum level of IL-6 in baicalin treatment+periodontitis group was significantly lower than that in periodontitis group at week 6 and 8 (P<0.01). The serum level of IL-4 in periodontitis group was significantly lower than that in control and baicalin treatment+periodontitis group (P<0.01). The serum level of IL-4 in baicalin treatment+periodontitis group was significantly higher than that in periodontitis group at weeks 6 and 8 (P<0.01).CONCLUSION: The pathogenesis of periodontitis is closely related to the imbalance of Th1/Th2 cytokines, characterized by increased serum level of IL-6 and the decreased serum level of IL-4. Baicalin plays a significant role in treating mouse periodontitis by decreasing the serum level of IL-6 and increasing the serum level of IL-4.     

Change of nitric oxide concentration in ligature-induced periodontitis in rats

AIM: To study the possible role of nitric oxide (NO) in the development of periodontitis and the relationship between the NO concentration and the attachment loss. METHODS: Seventy-two Sprague-Dawley rats were randomly assigned to two groups, the control group and periodontitis group. Experimental periodontitis in rats was produced by a ligature of braided silk. The nitric oxide concentration was indirectly ascertained by the concentration of nitrite (NO2-) and nitrate (NO3-) in the gingival tissue, which was assayed by spectrophotometry. The attachment loss (AL) was measured by the technology of the cellular graphics engineering research. The histopathologic change in periodontium was observed under a light microscope by using the histotomy. RESULTS: Compared to control group, the NO2-/NO3- concentration in gingival tissue was significantly higher in periodontitis group at four weeks and eight weeks following ligation (P<0.01). In periodontitis group, the NO2-/NO3- concentration in gingival tissue was higher at eight weeks than that at four weeks following ligation (P<0.01). At four weeks and eight weeks, the AL in experimental periodontitis in rats was significantly increased than that at one week after ligation (P<0.01); and the AL was also much higher at eight weeks than that at four weeks (P<0.01). CONCLUSIONS: The NO2-/NO3- concentration in the gingival tissue in periodontitis group was significantly higher than that in control group. These results demonstrate that the NO2-/NO3- concentration is related to the severity of AL, and NO synthesis is very important to the process of inflammation and lesion in periodontium. Reducing NO production may be of great therapeutic value in the treatment of periodontitis.     

Role of interleukin-4 in the development of periodontitis in mouse model

AIM: The purpose of this study was to investigate the role of interleukin-4 (IL-4) in the development of periodontitis in mice by low dosage of Trichinella spiralis (T. spiralis) infection.METHODS: Twenty-seven male Kunming mice in specific pathogen free grade were randomly divided into three groups: (1) the normal control group; (2) the experimental periodontitis group, which was produced by ligature of braided silk around the first maxillary molar, and was inoculated with putative periodontopathic bacteria; (3) the periodontitis with T. spiralis infection group. The mice were sacrificed at the end of 1, 3 and 5 weeks. The probing depth (PD) was measured before the mice were euthanized. The histological change of periodontal tissues was observed under the microscope after the samples were stained with hematoxylin and eosin. Furthermore, the serum level of IL-4 was determined by ELISA. RESULTS: (1) The serum level of IL-4 in T. spiralis-infected group was significantly higher than that in experimental periodontitis group (P<0.01). (2) The PD in T. spiralis-infected group was significantly lower than that in experimental periodontitis group (P<0.01). (3) Only a mild inflammatory response was observed in T. spiralis-infected animals. CONCLUSION: T. spiralis infection upregulates IL-4 expression and attenuates periodontitis in mice.     

Effect of tetracycline on the avidity of serum IgG antibody against porphyromonas gingivalis in patients with aggressive periodontitis

AIM:To evaluate the effect of mechanical periodontal treatment combined with tetracycline on periodontal attachment level (AL) and the avidity of serum antibody against porphyromonas gingivalis(P. gingivalis) in patients with aggressive periodontitis(AgP). METHODS:Twenty-five patients with AgP and twenty periodontally healthy controls were studied (HS). Clinical examination and recordings of AL were performed before and 3, 6 and 12 months after the periodontal treatment. The avidity of IgG antibody against P. gingivalis lipopolysaccharide(LPS) was measured by diethylamine dissociation ELISA. RESULTS:A significant improvement in AL was observed following treatment (P<0.01). The avidity of serum IgG antibody against P. gingivalis increased compared with controls, and was decreased significantly after mechanical periodontal treatment combined with tetracycline (P<0.01). CONCLUSION:Our results demonstrate that mechanical periodontal treatment combined with tetracycline provides clinically favorable results in patients with AgP.     

The inhibitory effect of aminoguanidine on periodontitis in rats

AIM: To study the inhibitory effect of aminoguanidine(AG) on periodontitis. METHODS: Experimental periodontitis was produced in rats by a ligature of braided silk, the NO concentration was assayed by spectrophototometry, the attachment loss of periodontium was measured by using technology for image and graphics engineering research and the histopathologic changes of periodontium were also examined under a light microscope. RESULTS: The NO concentration significantly decreased after AG treatment for 4 weeks, and the inflammation and the damages of periodontium was also reduced significantly. CONCLUSION: The inhibition of iNOS by AG may be a potential therapeutic strategy for the treatment of periodontitis.     

Role of 78 kD glucose-regulated protein in development of hepatopulmonary syndrome induced by multiple pathogenic factors

AIM: To explore the role of 78 kD glucose-regulated protein (GRP78) in the development of hepatopulmonary syndrome (HPS) in rats and the relation to intestinal endotoxemia (IETM). METHODS: The experimental animals were randomly divided into HPS groups of the 4th week, the 6th week and the 8th week. Normal control groups at the corresponding time points were also set up. The Wistar rat model of HPS produced in the process of liver cirrhosis was induced by employing multiple pathogenic factors to the animals. The rats in normal control group were designed by feeding with standard diet and tap water. Histopathological changes of the lung and liver were observed under microscope with the staining of hematoxylin and eosin (HE). The concentrations of alanine amino transferase (ALT), endotoxin and tumor necrosis factor α (TNF-α) in plasma, the contents of TNF-α and malondialdehyde (MDA) in the lung tissues were detected. The expression of GRP78 at mRNA and protein levels in the lungs was measured by the methods of RT-PCR and Western blotting, respectively. RESULTS: The level of endotoxin in plasma was gradually increased with the HPS development. The expression of GRP78 at mRNA and protein levels was also gradually increased with the HPS development and was significant at every time point. The endotoxin in plasma was positively correlated with the expression of GRP78 protein in the lung tissues of the rats with HPS. With the HPS development, the levels of ALT and TNF-α in plasma and the contents of TNF-α and MDA in the lung tissues were gradually increased. The content of endotoxin in plasma and the protein expression of GRP78 in the lung tissues were positively correlated with the contents of TNF-α in plasma and TNF-α and MDA in the lung tissues. The contents of TNF-α in plasma and GRP78 at mRNA and protein levels and TNF-α in the lung tissues were higher in the rats with HPS at every time point than those in normal control group. At the 6th week and the 8th week, the contents of endotoxin and ALT in plasma and MDA in the lung tissues of the rats with HPS were significantly higher than those in normal control group. CONCLUSION: IETM originated from the liver cirrhosis acts as a critical stressor of endoplasmic reticulum (ER) stress and activates ER stress in the lung by oxidative stress, resulting in increased expression of GRP78. Therefore,the increased expression of GRP78 induced by ER stress may play an important role in the development of HPS in rats.     

Expression of MMP3 in subchondral bones in early experimental osteoarthritis

AIM: To demonstrate that matrix metalloproteinase 3(MMP3)plays MMP3 play an important role in the pathogenesis of osteoarthritis by studying the expression of MMP3 in subchondral bones in early experimental osteoarthritis at gene and protein levels. METHODS: The SD rats were randomly divided into 2 groups: experimental group and control group, each containing 30 rats with similar body weight. The right knee joints of the rats in experimental group underwent surgery, which involved in both medial collateral ligament (MCL) transection and medial meniscectomy, while the animals in control group were only carried out a sham operation. The rats were killed at the 1st, 2nd and 4th weeks post-surgery to obtain the right knee joints. Pathological analysis was performed to validate this early osteoarthritic rat model. The expression of MMP3 in subchondral bones at mRNA and protein levels was evaluated by real-time polymerase chain reaction and immunohistochemical staining, respectively. RESULTS: The expression of MMP3 in subchondral bones was significantly increased at both the 1st and 2nd weeks post-surgery in experimental group, with the fold changes of 8.34 (P<0.05) and 4.85 (P<0.05), respectively, as compared with control group. No differentially expression of MMP3 was observed at the 4th week post-surgery between these 2 groups. A lot of MMP3 positive cells, including small mononuclear cells and bigger polynuclear giant cells, were found in subchondral bones in experimental group at the 1st and 2nd weeks post-surgery,but not in control group. At the 4th week post-surgery, no MMP3 positive cells were found in subchondral bones of both groups. CONCLUSION: MMP3 plays an important role in the pathogenesis of early experimental osteoarthritis.     

Effect of hyperbaric oxygen on NSCs in the neonatal rat with hypoxic-ischemic brain damage

AIM: To discuss the mechanism of hyperbaric oxygen (HBO) therapy by assessing the changes of neural stem cells (NSCs), after hypoxic-ischemic brain damage (HIBD) in neonatal rats. METHODS: Seven-day-old SD rat pups were randomly divided into 4 groups: control group (CON, n=16), HIBD group (n=16), hyperbaric air group (HBA, n=16), and HBO group (n=16). The HIBD model was produced by permanent occlusion of left common carotid artery and was exposed to a mixture of 8% oxygen and 92% nitrogen for 2 h (at 37 ℃). HBA and HBO treatment was administered by placing pups in a chamber (2 ATA for 1 h) 1 h after hypoxia exposure and performed once daily for 7 days. BrdU immunohistochemistry was used to assess how the insult had affected NSCs in the SVZ of the lateral ventricle and DG of the hippocampus. The NSCs from the ipsilateral SVZs were isolated at 3 weeks recovery from hypoxia-ischemia (HI). The number of spheres was then counted as an index of the number of NSCs residing within the SVZ. RESULTS: At 3 week survival, the SVZ of HIBD group was smaller and markedly less cellular than control group. BrdU-positive cells were dramatically decreased in the SVZ and DG of the affected hemisphere (P<0.01) and by in vitro cell culture it contained less NSCs in the SVZ of the affected hemisphere, too. HBO resulted in weaker proliferation of BrdU-positive cells in the SVZ and DG. CONCLUSION: Hypoxia-ischemia depletes the rat NSCs in SVZ and DG, HBO can weak this depletion, but HBA has no effect.     

Effect of Zhiqi oral solution on adult periodontitis

AIM:To evaluate therapeutic effect of Zhiqi oral solution on adult periodontitis.METHODS:Supragingival scaling and root planning were carried out in 100 patients with adult periodontitis. Then the patients with periodontitis were divided into two groups randomly. 32 patients in the control group took orally Metronidazole and 68 patients in the experimental group took orally Zhiqi oral solution. The pain reaction, bleeding index, probing depth, plaque index, changes of microorganisms in periodontal pocket and side effect before and after the treatment were observed at a 30 days observation period.RESULTS:Zhiqi oral solution had a therapeutic effect on periodontitis, compared with the control group (P＜0.05). The bleeding index and plaque index in patients of two groups were improvedobviously compared with before treatment (P＜0.05). However Zhiqi oral solution had an obvious effect on decreasing the probing depth(P＜0.05).CONCLUSION:Zhiqi oral solution improves effectively the condition of periodontium, and its supplementary treatment effect on adult periodontitis is obvious.     

Effect of simvastatin on expression of integrin-linked kinase and renal tubulointerstitium injury in rats induced by high fat diet

AIM: To explore the effect of simvastatin on expression of integrin-linked kinase (ILK) and the injury of renal tubulointerstitium in the rats induced by high fat diet. METHODS: Fifty-four 6-8 week-old female Wistar rats were randomly assigned to the following three groups: high fat diet group, simvastatin group (rats were fed with high fat diet plus 10 mg·kg-1·d-1 simvastatin) and control group. Six rats in each group were sacrificed at 4th week, 10th week, and the others at 20th week. The injury of renal tubulointerstitium was observed under microscope with HE staining and the expression of renal ILK was determined by Western blotting analysis and immunohistochemistry. Levels of total cholesterol (TC) and triglyceride (TG) in serum were measured by enzymatic colormetric methods. RESULTS: The serum TC and TG levels and the expression of renal ILK significantly increased in both high-fat diet group and simvastatin group, compared to control group at 4th week, reaching a maximum at 20th week (P<0.01). Tubulointerstitium injuries including vacuolar degeneration, syncytial change, clody swelling, necrosis and atrophy of renal tubular epithelial cells, thinning of tubal wall, lumens compensational expansion or even abolition, and inflammatory cell infiltration, interstitial fibrosis were found in both high fat diet group and simvastatin group, compared to control group at 4th week, worsened to a maximum at 20th week. However, all of these ameliorated in simvastatin group, compared to high fat diet group at each time point. CONCLUSION: The results indicate that high-fat diet induces significant lesion of renal tubulointerstitium and increased expression of renal ILK. Simvastatin may play an important role in protecting against tubulointerstitium injury induced by hyperlipoidemia by down-regulating the expression of renal ILK.     

Early high-protein diet improves glucose metabolism in SGA rats via adiponectin-AMPK signaling

AIM: To investigate the effect of early high-protein diet on glucose metabolism in small-for-gestational-age (SGA) rats and the role of adiponectin-AMP-activated protein (AMPK) signaling in this process. METHODS: Forty-eight neonatal male SGA rats were established by maternal food restriction throughout the period of pregnancy. The animals were randomly divided into SGA control group (CS group, 24 rats) and high-protein intervention SGA group (HPS group, 24 rats) when born. Twenty-four normal neonatal male rats were used as normal control group (CN group). The rats in CN group and CS group were breastfed for 3 weeks and their mothers were provided free access to basic diet. After weaning, they were provided free access to basic diet until 12 weeks of age. The rats in HPS group were breastfed for 3 weeks and their mothers were provided free access to high-protein diet. After weaning, they were provided free access to high-protein diet until 4 weeks of age. At the 4th week of age, they were provided free access to basic diet until 12 weeks of age. From 4 to 12 weeks of age, fasting blood glucose and insulin were measured and homeostasis model assessment of insulin resistance index (HOMA-IR) was calculated. The serum adiponectin level and the visceral fat mass (VFM) were detected. The percentage of VFM to body weight (VFM%) was calculated. The visceral fat was paraffin-embedded and the adipocyte area was determined. The expression of AMPKα,phosphorylated AMPKα (p-AMPKα) and glucose transporter 4 (GLUT4) in skeletal muscle was analyzed. At the 12th week of age, the oral glucose tolerance test (OGTT) was performed. RESULTS: At the 4th week of age, no significant difference of HOMA-IR among groups was observed. At the 12th week of age, HOMA-IR in CS group was significantly higher than that in CN group and HPS group. No significant difference of HOMA-IR between CN group and HPS group was found. From 4 to 12 weeks of age, VFM% and adipocyte area of visceral fat in CS group were significantly higher than those in CN group and HPS group. No significant difference of VFM% and adipocyte area of visceral fat between CN group and HPS group was observed. The level of serum adiponectin, and the expression of p-AMPKα and GLUT4 in skeletal muscle were significantly lower in CS group than those in CN group and HPS group. The protein levels of p-AMPKα and GLUT4 were not significantly different between CN group and HPS group. No significant difference in the expression of AMPKα in skeletal muscle among groups was observed. At the 12th week of age, the area under the curve (AUC) of glucose level in OGTT was higher in CS group than that in CN group and HPS group. No significant difference of AUC of glucose level between CN group and HPS group was found. CONCLUSION: Early high protein diet may improve glucose metabolism in SGA rats, partly by avoiding excessive accumulation of visceral fat and possibly by activating adiponectin-AMPK signal pathway to increase GLUT4 expression.     

Effect of tea polyphenols on the contractile function of the papillary muscles of right ventricle in diabetic rats

AIM: To investigate the effect of tea polyphenols (TP) on the contractile function of the papillary muscles of right ventricle in the sixth and eighth week diabetic rats and the control rats. METHODS: Rats were induced to diabetic by an intravenous injection of alloxan. The papillary muscles of right ventricle in the sixth and eighth week diabetic rats were segregated and superfused with oxygenated Tyrode's solution. The contractile function and functional change under the electric stimulation state was recorded and compared between diabetic group and control group. RESULTS: 1/2 diastole interval elongation (P<0.05) and the depression of +dT/dtmax (P<0.01) and -dT/dtmax (P<0.05) of the papillary muscles of right ventricle were showed in the 6th week diabetic rats, while further damages, such as tension addition (P<0.01), 1/2 diastole interval elongation (P<0.01) and the depression of +dT/dtmax (P<0.01) and -dT/dtmax (P<0.01) in 8th week diabetic rats were also observed. TP at certain concentrations (15-120 mg/L) did not produce any effect on the 8th week diabetic rat's papillary muscle, but the positive muscle strength has been showed in the control rats and the sixth week diabetic rats. CONCLUSIONS: TP produces the positive muscle strength in the early diabetic cardiomyopathy, but has no beneficial effect on serious impaired diabetic myocardium.     

Effects of macrophage polarization during development of liver cirrhosis in rats

AIM: To explore the state of macrophage polarization and its relation with intestinal endotoxemia-endoplasmic reticulum stress in the development of liver cirrhosis induced by multiple pathogenic factors in rats. METHODS: The male SD rats (n=36) were randomly divided into normal control group and liver cirrhosis model group, and sacrificed at the end of the 4th, 6th and 8th weeks. The rat model of liver cirrhosis was induced by multiple pathogenic factors. The levels of alanine aminotransferase (ALT), endotoxin, homocysteine (Hcy) in the plasma, and inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), arginase-1 (Arg-1) and interleukin-10 (IL-10) in the liver tissues were detected by ELISA. Histopathological change of the liver was observed under microscope with the staining of hematoxylin and eosin (HE) and van Gieson (VG). The expression of glucose-regulated protein 78 (Grp78), nuclear factor-kappa B (NF-κB), interferon-regulatory factor 5 (IRF5), CD86, CD206 and transforming growth factor-β1 (TGF-β1) at mRNA levels in the liver tissues were detected by the method of real-time fluorescence quantitative PCR.RESULTS: Compared with the corresponding normal control group, the levels of ALT, endotoxin, Hcy in the plasma and Grp78 mRNA in the liver tissues in liver cirrhosis model group were significantly and gradually increased (P<0.05). The mRNA expression of NF-κB, IRF5 and CD86, and the protein levels of iNOS, TNF-α and IL-6 in the liver tissues were significantly increased (P<0.05), and they successively increased from the 4th week to the 6th week and decreased reversely at the 8th week. The mRNA expression of CD206, TGF-β1, Arg-1 and IL-10 in the liver tissues were significantly increased from the 6th week to the 8th week (P<0.05), and no significant difference at the 4th week was observed. The level of endotoxin in the plasma was correlated with the mRNA expression of Grp78 in the liver tissues (P<0.01). Both endotoxin in the plasma and Grp78 mRNA in the liver tissues were correlated with the mRNA expression of CD86 and CD206 in the liver tissues (P<0.01).CONCLUSION: The pathway of liver damage-intestinal endotoxemia-endoplasmic reticulum stress-macrophage polarization may be critical in the pathogenesis of liver cirrhosis induced by multiple pathogenic factors.     

Inhibitory effect of salidroside on liver oxidative stress in rats with non-alcoholic steatohepatitis

AIM：To explore the effects of salidroside (SDS) on the oxidative stress in liver tissues from rats with non-alcoholic steatohepatitis (NASH). METHODS：The experimental animal model of NASH was established in SD rats fed on high-fat and high-cholesterol diet (HFHCD) for 14 weeks. SDS (300 mg·kg-1·d-1) was administered via gavage daily from the 8th week after HFHCD feeding. At the end of the 14th week, serum samples were taken for detection of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG) and total cholesterol (TC). Liver tissues were taken for TG, TC, malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) detection. The content of 8-isoprostaglandin F2α (8-iso-PGF2α) in liver tissues was determined by ELISA. The liver histopathological changes were observed under microscope with HE staining. The expression of 8-hydroxydeoxyguanosine (8-OHdG) in liver tissues was determined by immunohistochemical staining. RESULTS：At the end of the 14th week, ALT, AST, TG and TC in serum, and TG, TC, MDA and 8-iso-PGF2α in liver homogenate in NASH model group were significantly increased compared with control group, while SOD and GSH in liver tissues were significantly decreased. The liver expression of 8-OHdG in NASH model group was higher than that in control group. Compared with NASH model group, SDS significantly inhibited the elevation of serum ALT, AST, TG and TC, and liver TG, TC, MDA and 8-iso-PGF2α, but increased the levels of SOD and GSH in liver tissues. Meanwhile, the liver histopathological score and 8-OHdG expression were decreased in SDS treatment group. CONCLUSION：Salidroside can effectively inhibit steatohepatitis induced by HFHCD, and its antioxidant effect may be one of the mechanisms.     

Effects of capsaicin on cognitive impairment and mitochondria-associated endoplasmic reticulum membranes in rats with chronic cerebral hypoperfusion

AIM:To observe the effects of capsaicin on cognitive impairment and mitochondria-associated endoplasmic reticulum membranes (MAMs) of hippocampal CA1 area in the rats with chronic cerebral hypoperfusion (CCH), and to investigate the underlying molecule mechanism of cognitive defects induced by ischemia. METHODS:Healthy male Sprague-Dawley (SD) rats(n=48) were randomly divided into sham operation (sham) group,CCH model (CCH) group, capsaicin group,and solvent group, 12 rats in each group. Capsaicin at 2.5 mg/kg was intraperitoneally injected twice a week for 4 weeks, starting on the 7th day after surgery. The rats in solvent group were given the same amount of solvent at the same time and under the same conditions. Morris water maze, object recognition test and open field test were conducted to analyze the cognitive related behavior performance on the 4th week after surgery. The changes of MAMs in the hippocampal CA1 region were observed under transmission electron microscope, the co-localization of the MAMs was observed by immunofluorescence double-labeling, and the expression of mitofusin 2 (Mfn2) in the hippocampal tissue was determined by Western blot.RESULTS:Four weeks after the operation, the behavior tests showed that the cognitive function of CCH rats was impaired compared with sham operation group. Compared with solvent group, spatial learning and memory in capsaicin group was improved significantly. The results of transmission electron microscope and confocal microscope showed that the distance of MAMs in the hippocampal CA1 area of CCH rats was increased compared with sham operation group, and the co-localization of the contacts was decreased (P<0.05). Compared with solvent group, the correlation between the mitochondria and ER in capsaicin group was increased (P<0.05). The protein level of Mfn2 in CCH group was significantly lower than that in sham group (P<0.05). Compared with solvent group, the protein level of Mfn2 in capsaicin group was higher (P<0.05). CONCLUSION:CCH rats showed decreased cognitive function and loosen MAMs. Capsaicin improves the cognitive behavior of CCH rats by up-regulation of MAMs.     

Effect of tetracycline combined with anti-inflammation drug and tetracycline on the level of serum IgG antibody titer in early-onset periodontitis

AIM: The purpose of this study was to evaluate the effect of tetracycline combined with anti-inflammation drug on the serum antibody level against porphyromonas gingivalis (Pg) in patients with early-onset periodontitis (EOP). METHODS: The study population consisted of 12 individuals with early-onset periodontitis, 16 patients with adult periodontitis (AP) and 12 periodontally healthy subjects (HS). Clinical examination and recordings of probing pocket depth (PPD), periodontal attachment level (PAL) and bleeding on probing (BOP) were performed prior to treatment and at three months following the periodontal treatment. The serum antibody titer against Pg in patients with EOP was measured at diagnosis and at the termination of treatmeat. RESULTS: A significant improvement was observed in probing pocket depth, periodontal attachment level and gingival bleeding index post treatment for three months. The serum IgG antibody titer against porphyromonas gingivalis was decreased significantly after the treatment. CONCLUSION: Our results demonstrate that mechanical periodontal treatment combined with tetracycline and anti-inflammation drug provides clinically favorable results in patients with early-onset periodontitis.