Protective effect of liraglutide on the myocardium of type 2 diabetic rats by inhibiting polyadenosine diphosphate-ribose polymerase-1

BACKGROUND In recent years,studies have found that the occurrence and development of diabetic cardiomyopathy(DCM)is closely related to an increase in polyadenosine diphosphate-ribose polymerase-1(PARP-1)activity.PARP-1 activation could be involved in the pathophysiological process of DCM by promoting oxidative stress,the inflammatory response,apoptosis and myocardial fibrosis.AIM To investigate the mechanism of liraglutide in improving myocardial injury in type 2 diabetic rats,further clarified the protective effect of liraglutide on the heart,and provided a new option for the treatment of DCM.METHODS Forty healthy male SD rats aged 6 wk were randomly divided into two groups,a normal control group(n=10)and a model group(n=30),which were fed an ordinary diet and a high-sugar and high-fat diet,respectively.After successful modeling,the rats in the model group were fed a high-glucose and high-fat diet for 4 wk and randomly divided into a model group and an intervention group(further divided into a high-dose group and a low-dose group).The rats were fed a high-glucose and high-fat diet for 8 wk and then started drug intervention.Blood samples were collected from the abdominal aorta to detect fasting blood glucose and lipid profiles.Intact heart tissue was dissected,and its weight was used to calculate the heart weight index.Haematoxylin and eosin staining was used to observe the pathological changes in the myocardium and the expression of PARP-1 in the heart by immunohistochemistry.RESULTS The body weight and heart weight index of rats in the model group were significantly increased compared with those in the normal control group,and those in the intervention group were decreased compared with those in the model group,with a more obvious decrease observed in the high-dose group(P<0.05).In the model group,myocardial fibers were disordered,and inflammatory cells and interstitial fibrosis were observed.The cardiomyopathy of rats in the intervention group was improved to different degrees,the myocardial fibers were arranged neatly,and the myocardial cells were clearly striated;the improvement was more obvious in the high-dose group.Compared with the normal control group,the expression of PARP-1 in myocardial tissue of the model group was increased,and the difference was statistically significant(P<0.05).After liraglutide intervention,compared with the model group,the expression of PARP-1 in myocardial tissue was decreased,and the reduction was more obvious in the high-dose group(P<0.05)but still higher than that in the normal control group.CONCLUSION Liraglutide may improve myocardial injury in type 2 diabetic rats by inhibiting the expression of myocardial PARP-1 in a dose-dependent manner.

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

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

桂枝茯苓胶囊联合戈舍瑞林对子宫肌瘤大鼠模型醛酮还原酶1C3和内分泌的影响

目的观察桂枝茯苓胶囊联合戈舍瑞林对子宫肌瘤大鼠模型醛酮还原酶1C3(AKR1C3)和内分泌的影响。方法将36只7周龄雌性白细胞介素-2受体共同Υ链(IL2RG)大鼠随机分为空白对照组、模型对照组和联合治疗组,每组各12只。模型对照组和联合治疗组通过雌孕激素药物建立子宫肌瘤模型。造模结束后第2天,空白对照组和模型对照组予蒸馏水5 mL灌胃,联合治疗组予桂枝茯苓胶囊混悬液0.70 g/(kg·d)+戈舍瑞林1.25 mg/(kg·d)灌胃,连续6周。采用酶联免疫吸附法测定各组大鼠血清雌二醇、孕酮和催乳素水平,实时荧光定量聚合酶链式反应法检测AKR1C3 mRNA表达,蛋白免疫印迹法检测Ⅰ型胶原、转化生长因子β(TGF-β)、纤溶酶原激活物抑制剂-1(PAI-1)、半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)、B淋巴细胞瘤-2(Bcl-2)、Bcl-2相关X蛋白(Bax)蛋白表达。结果与空白对照组相比,模型对照组雌二醇、孕酮和催乳素含量均升高(P<0.05);与模型对照组相比,联合治疗组雌二醇、孕酮和催乳素含量降低(P<0.05)。与空白对照组相比,模型对照组AKR1C3 mRNA表达含量升高(P<0.05);与模型对照组相比,联合治疗组AKR1C3 mRNA表达含量降低(P<0.05)。与空白对照组相比,模型对照组Ⅰ型胶原、PAI-1和TGF-β蛋白表达均升高(P<0.05);与模型对照组相比,联合治疗组Ⅰ型胶原、PAI-1和TGF-β蛋白表达均降低(P<0.05)。与空白对照组相比,模型对照组Caspase-3和Bax蛋白表达降低(P<0.05),Bcl-2蛋白表达升高(P<0.05);与模型对照组相比,联合治疗组Caspase-3和Bax蛋白表达升高(P<0.05),Bcl-2蛋白表达降低(P<0.05)。结论桂枝茯苓胶囊联合戈舍瑞林能降低子宫肌瘤大鼠雌二醇、孕酮和催乳素水平,抑制AKR1C3表达,具有抗增殖和促凋亡的作用,可抑制子宫肌瘤生长。

Effect of cholecystokinin on cytokines during endotoxic shock in rats

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

Inhibiting effect of antisense oligonucleotides phosphorthioate on gene expression of TIMP-1 in rat liver fibrosis

AIM: To observe the inhibition of antisense oligonucleotides (asON) phosphorthioate to the tissue inhibitors metalloproteinase-1 (TIMP-1) gene and protein expression in the liver tissue of immunologically induced hepatic fibrosis rats. The possibility of reversing hepatic fibrosis through gene therapy was observed. METHODS: Human serum albumin (HSA) was used to attack rats, as hepatic fibrosis model, in which asONs were used to block the gene and protein expressing TIMP-1. According to the analysis of modulator, structure protein, coding series of TIMP-1 genome, we designed four different asONs. These asONs were injected into the hepatic fibrosis models through coccygeal vein. The results was observed by RT-PCR for measuring TIMP-1 mRNA expression, immunohistochemistry and in situ hybridization for collagen I, II, special staining of collagen fiber, and electron microscopic examination. RESULTS: Hepatic fibrosis could last within 363 days in our modified model. The expressing level of TIMP-1 was high during hepatic fibrosis process. It has been proved by the immunohistochemical and the electron microscopic examination that the asON phosphorthioate of TIMP-1 could exactly express in vivo. The effect of colchicine was demonstrated to inhibit the expressing level of mRNA and the content of collagen I, III in the liver of experimental hepatic fibrosis rats. However, the electron microscopy research and the pathologic grading of hepatic fibrosis showed that there was no significant difference between the treatment group and the model group (P】 0.05). CONCLUSION: The experimental rat model of hepatic fibrosis is one of the preferable models to estimate the curative effect of anti-hepatic fibrosis drugs. The asON phosphorthioate of TIMP-1 could block the gene and protein expression of TIMP-1 in the liver of experimental hepatic fibrosis rats at the mRNA level. It is possible to reverse hepatic fibrosis, and it is expected to study a new drug of antihepatic fibrosis on the genetic level. Colchicine has very limited therapeutic effect on hepatic fibrosis, furthermore, its toxicity and side effects are obvious.

Lipopolysaccharide “Two-hit” Induced Refractory Hypoxemia Acute Respiratory Distress Model in Rats

To establish a stable and reliable model of refractory hypoxemia acute respiratory distress syndrome （ARDS） and examine its pathological mechanisms, a total of 144 healthy male Wistar rats were randomized into 4 groups： group Ⅰ （saline control group）, group Ⅱ （LPS intravenous ＂single-hit＂ group）, group Ⅲ （LPS intratracheal ＂single-hit＂ group） and Group IV （LPS ＂two-hit＂ group）. Rats were intravenously injected or intratracheally instilled with a large dose of LPS （10 mg/kg in 0.5 mL） to simulate a single attack of ARDS, or intraperitoneally injected with a small dose of LPS （1 mg/kg） followed by tracheal instillation with median dose of LPS （5 mg/kg） to establish a ＂two-hit＂ model. Rats in each group were monitored by arterial blood gas analysis and visual inspection for three consecutive days. Arterial blood gas values, lung wet/dry weight ratio and pathological pulmonary changes were analyzed to determine the effects of each ALI/ARDS model. Concentrations of TNF-α, IL-1 and IL-10 in the bronchoalveolar lavage fluid （BALF） and blood plasma were meastired by using enzyme-linked immunosorbent assays （ELISA）. Our resulsts showed that single LPS-stimulation, whether through intravenous injection or tracheal instillation, could only induce ALl and temporary hypoxemia in rats. A two-hit LPS stimulation induces prolonged hypoxemia and specific pulmonary injury in rats, and is therefore a more ideal approximation of ARDS in the animal model. The pathogenesis of LPS two-hit-induced ARDS is associated with an uncontrolled systemic inflammatory response and inflammatory injury. It is concluded that the rat ARDS model produced by our LPS two-hit method is more stable and reliable than previous models, and closer to the diagnostic criteria of ARDS, and better mimics the pathological process of ARDS.

Transretinoic acid inhibits rats gastric epithelial dysplasia induced by N-methyi-N-nitro-N-nitrosoguanidine:influences on cell apoptosis and expression of its regulatory genes

INTRODUCTIONGastric epithelial dysplasia (GED) hypothetically is a straight-forward concept: dysplastic epithelium replacing the normal gastric epithelium of the stomach [1].In the stomach ,like any other segment of the gut ,it is defined as an unequivocal non-invasive epithelial change[2,3].The observation of gastric dysplasia as a cancerous lesion was recognized over a century ago ,but it is only after the advent of gastroscopy that its clinical significance has been stressed[4-7].

Overexpression of heme oxygenase-1 protects smooth muscle cells against oxidative injury and inhibits cell proliferation

To investigate whether the expression of exogenous heme oxygenase-1 (HO-1) gene within vascular smooth muscle cells (VSMC) could protect the cells from free radical attack and inhibit cell proliferation, we established an in vitro transfection of human HO-1 gene into rat VSMC mediated by a retroviral vector. The results showed that the profound expression of HO-1 protein as well as HO activity was 1.8- and 2.0-fold increased respectively in the transfected cells compared to the non-transfected ones. The treatment of VSMC with different concentrations of H2O2 led to the remarkable cell damage as indicated by survival rate and LDH leakage. However, the resistance of the HO-1 transfected VSMC against H2O2 was significantly raised. This protective effect was dramatically diminished when the transfected VSMC were pretreated with ZnPP-IX, a specific inhibitor of HO, for 24 h. In addition, we found that the growth potential of the transfected cells was significantly inhibited directly by increased activity of HO-1, and this effect might be related to decreased phosphorylation of MAPK. These results suggest that the overexpression of introduced hHO-1 is potentially able to reduce the risk factors of atherosclerosis, partially due to its cellular protection against oxidative injury and to its inhibitory effect on cellular proliferation.

Mechanisms mediating cholinergic antral circular smooth muscle contraction in rats

AIM:To investigate the pathway(s)mediating rat antral circular smooth muscle contractile responses to the cholinomimetic agent,bethanechol and the subtypes of muscarinic receptors mediating the cholinergic contraction. METHODS:Circular smooth muscle strips from the antrum of Sprague-Dawley rats were mounted in muscle baths in Krebs buffer.Isometric tension was recorded.Cumulative concentration-response curves were obtained for(+)-cis- dioxolane(cD),a nonspecific muscarinic agonist,at 10^(-8)- 10^(-4)mol/L,in the presence of tetrodotoxin(TTX,10^(-7)mol/L). Results were normalized to cross sectional area.A repeat concentration-response curve was obtained after incubation of the muscle for 90 min with antagonists for M1(pirenzepine), M2(methoctramine)and M3(darifenadn)muscarinic receptor subtypes.The sensitivity to PTX was tested by the ip injection of 100 mg/kg of PTX 5 d before the experiment.The antral circular smooth muscles were removed from PTX-treated and non-treated rats as strips and dispersed smooth muscle cells to identify whether PTX-linked pathway mediated the contractility to bethanechol. RESULTS:A dose-dependent contractile response observed with bethanechol,was not affected by TTx.The pretreatment of rats with pertussis toxin decreased the contraction induced by bethanechol.Lack of calcium as well as the presence of the L-type calcium channel blocker,nifedipine,also inhibited the cholinergic contraction,with a reduction in response from 2.5±0.4 g/mm^2 to 1.2±0.4 g/mm^2(P<0.05).The dose- response curves were shifted to the right by muscarinic antagonists in the following order of affinity:darifenacin (M_3)>methocramine(M_2)>pirenzepine(M_1). CONCLUSION:The muscarinic receptors-dependent contraction of rat antral circular smooth muscles was linked to the signal transduction pathway(s)involving pertussis-toxin sensitive GTP-binding proteins and to extracellular calcium via L-type voltage gated calcium channels.The presence of the residual contractile response after the treatment with nifedipine,suggests that an additional pathway could mediate the cholinergic contraction.The involvement of more than one muscarinic receptor(functionally predominant type 3 over type 2)also suggests more than one pathway mediating the cholinergic contraction in rat antrum.

缺氧预处理通过缺氧诱导因子-1α/基质细胞衍生因子-1通路对大鼠血液学相关指标的影响

目的探讨缺氧诱导因子-1α(HIF-1α)/基质细胞衍生因子-1(SDF-1)通路对缺氧预处理大鼠模型的作用。方法76只成年雄性SD大鼠,通过在低压氧舱(海拔5000 m)和西宁市(海拔2260 m)饲养建立缺氧预处理动物模型,随机分为6组:对照组(Ctrl组),高海拔缺氧预处理1 d组(HHP-1d),高海拔缺氧预处理4 d组(HHP-4d)、高海拔缺氧预处理15 d组(HHP-15d),高海拔缺氧预处理30 d组(HHP-30d),中海拔缺氧预处理组(MHP),其中Ctrl组、HHP-4d组、HHP-30d组与MHP组利用7.0 T小动物MRI,T2加权像(T2WI)观察颅内结构及基底动脉直径,连续性自旋动脉标记(ASL)观察海马区及脑干区脑血流,检测各组大鼠血常规,ELISA检测各组大鼠血清HIF-1α和SDF-1浓度及血浆血小板活化因子(PAF)及P-选择素(SELP)浓度。结果缺氧预处理条件下,颅内结构未见明显异常;基底动脉直径增宽,但无统计学意义;脑干区及海马区脑血流量明显升高,差异具有统计学意义(P<0.05),红细胞及白细胞升高,血小板下降,差异具有统计学意义(P<0.05),其中MHP组红细胞和血小板接近Ctrl组;缺氧预处理组HIF-1α浓度明显升高,SDF-1浓度(除HHP-1d组外)明显升高,HHP-1d、HHP-15d组PAF、SELP浓度明显升高,HHP-4d、HHP-30d组PAF浓度明显下降,HHP-4d组SELP浓度明显下降,差异均具有统计学意义(P<0.05)。结论缺氧预处理可通过HIF-1α/SDF-1通路增加机体氧储备量及免疫防御力,提高脑储备能力并发挥脑保护作用,其中以中海拔(海拔2260 m)饲养30 d预处理效果最佳。

探究电针廉泉穴对脑卒中后吞咽困难大鼠神经功能缺损的影响

目的探讨电针廉泉穴对脑卒中后吞咽困难(PSD)大鼠神经功能缺损的影响及潜在对瞬时受体电位香草酸亚型1(TRPV1)信号通路的调节机制作用。方法选用SPF级SD雄性大鼠60只,随机分为正常组12只(仅浅插栓线,未导致脑内动脉闭塞),余48只制作PSD模型,将造模成功的36只大鼠随机分为模型组、治疗组和治疗+咖啡酸组,每组12只。记录大鼠吞咽潜伏期和吞咽次数,生物信号采集器检测舌下神经放电、舌肌阈强度和收缩幅度,酶联免疫吸附测定血清P物质含量,甲苯胺蓝染色检测舌下神经核尼氏体数目,免疫组织化学检测舌下神经核TRPV1、五羟色胺(5-HT)、磷酸化p38、神经元型一氧化氮合酶(nNOS)蛋白表达水平。结果与正常组比较,模型组大鼠吞咽潜伏期、吞咽次数、舌下神经放电积分面积、舌肌收缩幅度、血清P物质含量、舌下神经核尼氏体数目、TRPV1及5-HT蛋白表达水平下降,舌肌阈强度和舌下神经核磷酸化p38、nNOS蛋白表达水平增加(P<0.05);与模型组比较,治疗组大鼠舌肌单收缩幅度、舌肌强直收缩幅度、血清P物质含量、舌下神经核尼氏体数目、TRPV1及5-HT蛋白表达水平增加[2.36±0.26 vs 1.77±0.22、3.46±0.36 vs 2.15±0.18、(3.92±0.38)ng/ml vs(1.69±0.17)ng/ml、(33.60±3.65)个vs(24.60±2.34)个、(19.85±2.11)%vs(9.79±1.07)%、(22.43±2.34)%vs(10.85±1.13)%,P<0.05]。结论电针廉泉穴可能通过激活TRPV1信号通路改善PSD大鼠神经功能缺损。

中枢IL-1β参与新奇应激大鼠的运动行为调控

目的 :观察中枢白细胞介素 1β (interleukin 1β ,IL 1β)在新奇应激 (noveltystress)诱发的大鼠运动行为 (mo torbehavior)反应中的作用。方法 :利用大鼠新奇环境应激箱诱发新奇应激 ;用大鼠脑立体定位技术与侧脑室埋管技术进行药物侧脑室微量注射 ,用行为遥感监测系统监测清醒大鼠运动行为反应 ,用行为学指标为描述大鼠静止行为 (immobility)的“静止行为平均百分数”(meanpercentimmobility ,MPI)。结果 :新奇应激可明显降低大鼠的MPI;非应激情况下 ,侧脑室预注射IL 1β特异性抗体不影响大鼠MPI;侧脑室预注射抗IL 1β抗体可拮抗新奇应激导致的大鼠MPI降低 ;新奇应激时 ,侧脑室预注射非特异性抗体分子IgG不影响大鼠MPI。结论 :中枢IL 1β参与调节新奇应激过程中大鼠运动行为反应的中枢调控。

调胃承气汤灌胃与灌肠对肠源性脓毒症大鼠肠上皮细胞occludin和ZO-1蛋白表达的影响

【目的】观察和比较调胃承气汤灌胃与灌肠对肠源性脓毒症(GOS)大鼠肠黏膜屏障的影响。【方法】将48只大鼠随机分为假手术组,模型组,中药灌胃高、低剂量组(分别给予调胃承气汤9.450、4.725 g/kg灌胃),中药灌肠高、低剂量组(分别给予调胃承气汤9.450、4.725 g/kg灌肠),每组8只。采用盲肠结扎穿刺法(CLP)复制GOS大鼠模型。各组在造模后2、10、24 h分别对应给药。采用酶联免疫吸附分析(ELISA)检测血清降钙素原(PCT)、D-乳酸(D-LA)水平,逆转录实时定量PCR(RT-qPCR)法检测小肠组织occludin、闭锁小带蛋白(ZO-1)基因及肝脏组织肿瘤坏死因子α(TNF-α)、干扰素γ(INF-γ)基因表达水平,免疫组化法检测小肠组织occludin、ZO-1蛋白的表达,苏木素—伊红(HE)染色观察小肠病理组织结构的变化。【结果】与假手术组比较,模型组大鼠小肠组织结构有明显损伤,血清PCT和D-LA水平显著升高(P <0.01),小肠组织occludin、ZO-1基因相对表达水平明显下调(P <0.01),肝脏组织TNF-α、INF-γ基因相对表达水平显著上调(P <0.01),小肠组织occludin、ZO-1蛋白免疫组化阳性表达明显减少(P <0.05);与模型组比较,中药各治疗组能明显改善小肠的损伤程度,显著降低血清PCT和D-LA水平(P <0.05或P <0.01),上调小肠组织occludin和ZO-1基因相对表达水平,下调肝脏组织TNF-α和INF-γ基因相对表达水平(P <0.05或P <0.01),并且能提高小肠组织occludin和ZO-1蛋白免疫组化阳性表达(P <0.05或P <0.01);与灌胃组比较,中药灌肠组的治疗效果更为明显(P <0.05或P <0.01)。【结论】调胃承气汤可上调GOS模型大鼠肠上皮细胞紧密连接蛋白occludin、ZO-1及下调体内炎性因子TNF-α、INF-γ的表达,从而修复肠黏膜屏障,治疗GOS,且灌肠疗法要优于灌胃疗法。

低氧训练对大鼠骨骼肌HIF-1 mRNA及铁转运蛋白表达的影响

目的：探讨低氧、低氧训练对大鼠骨骼肌铁代谢的影响。方法：32只雄性SD大鼠随机均分为常氧安静组（NC）、常氧运动组（NE）、低氧安静组（HC）和低氧运动组（HE）。跑台训练（21～25m／min，每周增1m／min，1h／天，6天／周），HC组进行低氧暴露（13．6％氧，8h／天，6天／周）。原子吸收法、RT—PCR、Westernblot检测结果。结果：与NC组比，各组大鼠腓肠肌总铁含量升高（P〈0．05，P〈0．01）；HE组高于NE、HC组（P〈0．05）。HC和HE组骨骼肌HIF-1 mRNA表达高于NC、NE组（P〈0．01）。与NC组相比，NE、HC、HE组骨骼肌铁吸收蛋白升高（P〈0．05，P〈0．01）；NE、HC组铁释放蛋白下降（P〈0．05，P〈0．01），HE组升高（P〈0．01）；HE组各蛋白表达均高于NE和HC组（P〈0．01）。结论：大鼠适度运动和单纯低氧均能增加骨骼肌铁贮存，而低氧训练能促进骨骼肌铁吸收和铁释放。

丹参素在大鼠肝脏低温保存中对HO-1表达的影响

目的检测丹参素(Salviamiltiorriza Bunge,SB)或锌原卟啉(ZnPP)预处理的大鼠肝脏中血红素氧合酶-1(HO-1)的表达,研究丹参素对HO-1表达和肝脏病理改变的影响。方法将72只SD雄性大鼠随机分成A、B、C3组,每组24只。A组灌注保存液为乳酸林格液(LR),B、C组为SB(300 mg.kg-1)+LR,A、B组大鼠在制模前24 h用生理盐水5 mL行腹腔注射。C组在制模前24 h用ZnPP(1.5 mg.kg-1)腹腔注射。建立大鼠肝脏低温灌注保存模型,在保存0、1、3、6 h后,RT-PCR检测各组大鼠肝脏HO-1 mRNA表达的情况,光镜观察肝细胞形态改变。结果①B组大鼠肝脏HO-1 mRNA表达水平明显比其他2组高(均P<0.01)。②B组肝脏病理评分明显优于其他2组(均P<0.01)。病理评分和HO-1的表达呈负相关(r=-0.816,P<0.01)。结论丹参素灌注保存液可以诱导大鼠肝脏中HO-1的过表达,对肝脏低温保存起保护作用。

健胰方通过调控胰高血糖素样肽-1表达改善糖尿病大鼠胰岛细胞功能的研究

【目的】从胰高血糖素样肽-1(GLP-1)合成、分泌和灭活3个环节探索健胰方影响GLP-1改善胰岛细胞功能的可能机制。【方法】采用高脂饲料联合链脲佐菌素(STZ)法诱导糖尿病模型大鼠,随机分为模型组、复方组与正常组,干预4周。快速血糖仪测定血糖,Luminex液相蛋白芯片技术测定血浆GLP-1和胰岛素(insulin)水平,实时荧光定量PCR检测胰腺组织胰岛—十二指肠同源盒基因-1(PDX-1)m RNA表达,免疫组织化学法检测回肠L细胞合成GLP-1,酶联免疫法检测Ⅳ型二肽基肽酶(DPP-Ⅳ)。【结果】健胰方可显著降低糖尿病模型大鼠的空腹及糖负荷后血糖水平(P<0.05),促进糖尿病大鼠血中胰岛素的分泌(P<0.05),提高胰腺PDX-1 m RNA表达(P<0.05),提高血浆GLP-1水平与回肠组织GLP-1阳性反应面积及累积光密度值(P<0.05);但血清DPP-Ⅳ各组间比较无显著性差异(P>0.05)。【结论】健胰方可能是通过调控GLP-1的合成与分泌,从而促进PDX-1基因表达和胰岛素分泌以降低糖尿病大鼠血糖水平的。

蛛网膜下腔出血大鼠早期大脑皮层低氧诱导因子-1α表达与细胞凋亡相关性研究

目的:研究大鼠蛛网膜下腔出血(SAH)后大脑皮层低氧诱导因子-1α(HIF-1α)的表达情况及其与细胞凋亡可能存在的关系,初步探讨HIF-1α表达在SAH后早期脑损伤中的作用。方法:采用改良血管内穿刺法建立SAH模型。35只成年雄性SD大鼠随机分入假手术组和SAH 6、12、24、72 h组。采用免疫荧光染色技术检测HIF-1α的表达水平,末端脱氧核苷酸介导的X-dUTP缺口末端标记法(TUNEL)检测细胞凋亡,同时应用免疫荧光双标染色技术检测表达HIF-1α的细胞类型。结果:免疫荧光染色结果显示HIF-1α的表达在假手术组几乎未见(0.29%±0.30%),SAH后6 h增加(4.65%±1.01%),24 h达高峰(18.55%±4.23%),差异均有统计学意义(均P<0.05)。TUNEL法检测到大鼠大脑凋亡细胞数在SAH后增多,6 h时可见少数凋亡细胞(7.09%±2.34%),在24 h到达高峰(25.54%±7.36%),差异有统计学意义(P<0.05)。相关分析显示各组HIF-1α阳性率与TUNEL阳性率呈正相关(r=0.738,P<0.05)。免疫荧光双标染色显示HIF-1α蛋白主要表达于神经元,部分HIF-1α染色阳性的细胞核与TUNEL染色重合。结论:大鼠SAH后早期脑损伤过程中HIF-1α表达与细胞凋亡呈正相关,提示HIF-1α可能参与SAH后早期脑损伤病理生理过程。

骨碎补对骨折愈合中血生化指标及TGF-β_1表达的影响

为了进一步探讨骨碎补促进骨折愈合的机理。将 36只 SD大鼠随机分成生理盐水组 (A)、骨碎补组 (B)和伤科接骨片组(C) 3组 ,造成骨折模型后 ,分别给于生理盐水、骨碎补水煎液、伤科接骨片混悬液。术后第 7、14和 2 1天每组各处死动物 4只 ,取血并取出骨标本 ,进行血生化指标检测及骨切片 TGF-β1 免疫组化染色。结果显示骨折愈合过程中 ,骨碎补组血钙、磷浓度乘积显著高于对照组 (P<0 .0 1) ,血清 AL P活性始终高于对照组 (P<0 .0 1)。骨碎补组骨痂组织中 TGF- β1 免疫组化染色明显强于对照组。根据实验结果 ,推测骨碎补促进骨折愈合的机理可能有以下几方面 :1提高血钙、磷的浓度乘积 ,促进钙磷沉积 ;2增强机体内成骨活动 ,提高血清 AL P的活性 ;3增加 TGF-β1 在骨痂组织中的表达 。

血红素氧合酶-1对动脉粥样硬化大鼠MDA CD68及MMP-9的影响

目的:探讨血红素氧合酶-1(HO-1)对动脉粥样硬化斑块稳定性的影响及其机制。方法:30只雄性SD大鼠随机分为正常对照组、模型组及氯血红素组,分别接受正常饮食、高胆固醇饮食及高胆固醇饮食加氯血红素腹腔注射共3个月。实验结束后取血测血清丙二醛(MDA)水平,免疫组化法检测斑块内HO-1、CD68及金属蛋白酶-9(MMP-9)的表达。结果:模型组及氯血红素组与对照组比较,MDA、HO-1、CD68及MMP-9升高(P<0·05)。氯血红素组与模型组比较,主动脉内膜斑块面积占内膜面积比(RAAPI)显著减少(P<0·01),HO-1升高(P<0·01),MDA、CD68及MMP-9显著降低(P<0·05)。结论:HO-1可能通过减少MDA、CD68及MMP-9的表达,抑制脂质过氧化及炎症反应,下调纤维帽降解因素,从而达到稳定斑块的作用。

低氧耐力运动4周内大鼠ET-1与NO生成的时序性变化

目的:通过观察比较低氧耐力运动、单纯低氧暴露和常氧耐力运动4周内大鼠血清、肺组织和主动脉ET-1与NO生成的时序性变化规律,分析有机体对运动与低氧干预的初期应激特征。方法:将120只经过2周适应性训练的SD大鼠分为13组,分别给予中等强度的常氧耐力训练、低氧耐力训练和低氧安静暴露3种干预措施,测定了训练前、训练3、7、14、28天后恢复24h大鼠血清ET-1浓度、肺组织ET-1浓度和NOS(tNOS与iNOS)活性、腹主动脉ET-1和NOS(eNOS与iNOS)mRNA水平。结果:1)常氧运动与低氧运动3天均能够引起血清ET-1水平显著升高(40%~59%,P<0.05),但第7天均回落到训练前水平。低氧安静过程中血清ET-1无显著升高。2)3种干预措施3天均引起肺组织ET-1浓度明显升高(14%~23%,P<0.01),至第14~28天之间均回落至训练前水平。3)常氧运动与低氧运动4周内肺组织不同亚型NOS活性无明显变化,低氧安静第3~7天肺组织tNOS活性开始显著下降(第28天下降幅度为-44%,P<0.01),第14~28天之间iNOS活性开始显著下降(第28天下降幅度为-52%,P<0.01)。4)常氧运动第7~14天之间主动脉ET-1mRNA水平显著升高(115%,P<0.01),随后回落。低氧安静和低氧运动主动脉ET-1mRNA水平则是在开始3天内先显著下降(降幅-80%^-67%,P<0.01),随后逐渐升高,尤以低氧运动引起的升高幅度更为显著,第28天时达到训练前10倍以上(P<0.01),且显著高于其他两种干预措施组(P<0.01)。5)3种干预措施均使大鼠腹主动脉eNOS mRNA水平在3天之内显著升高,随后低氧安静至第3~7天之间以及常氧运动至第14~28天之间开始回落。然而,低氧运动则使腹主动脉eNOS mRNA水平在第14~28天突然大幅度升高,第28天时达到训练前10倍以上(P<0.01),且显著高于其他两种干预措施组(P<0.01)。结论:1)常氧耐力训练初期大鼠血管内皮和肺组织ET-1释放、主动脉ET-1基因表达以及同时期主动脉eNOS基因表达均一过性增加,使得ET-1与NO生成保持平衡。2)单纯低氧暴露初期大鼠肺组织ET-1浓度一过性增加,随后主动脉ET-1基因表达持续增加,同时期肺组织NOS活性持续下降,主动脉eNOS基因表达一过性增加,使得肺组织ET-1生成明显超过NO生成,可能是低氧暴露导致肺动脉压升高的机制。3)低氧环境下进行短期耐力训练后主动脉ET-1与eNOS基因表达均持续增加,同时肺组织NOS活性保持不下降,使得ET-1与NO生成能力同步大幅度提高并保持平衡。表明低氧环境下进行耐力训练有助于加快低氧习服。