Caspase-dependent retinal ganglion cell apoptosis in the rat model of acute diabetes

Background Neural apoptosis is generally believed to be mediated by two distinct pathways, caspase-dependant and caspase-independent pathways. This study investigated the apoptotic pathways involved in retinal ganglion cells in acute diabetes in rats. Methods Diabetes was induced in male Wistar rats by a peritoneal injection of streptozotocin （STZ）. Expression and localization of caspase-3 and apoptosis-inducing factor （AIF） proteins in the retina of diabetic rats was examined by Western blotting and immunohistochemistry analyses. Terminal transferase dUTP nick end labeling （TUNEL） assay and immunofluorescent staining specific for caspase-3 and AIF were applied to analyze for apoptosis of retinal ganglion cells. In addition, a caspase-3 inhibitor DEVD-CHO was injected intravitreally to further determine the apoptotic pathways of retinal ganglion cells triggered in acute diabetes. Results Two weeks after induction of diabetes, a significant increase in caspase-3 protein expression and localization occurred in the nerve fiber layer, ganglion cell layer, and inner plexiform layer of the retina. Four weeks after the onset of diabetes, the increase in caspase-3 expression was profound eight weeks postinduction of diabetes （P 〈0.05）. Meanwhile, no AIF protein expression was detected in this study. In addition, intravitreal administration of the caspase-3 inhibitor DEVD-CHO reduced apoptosis of retinal ganglion cells by its direct inhibitory action on caspase-3. Conclusion Caspase-dependent apoptotic pathways may be the main stimulant of STZ-induced retinal ganglion cell apoptosis in acute diabetes.     

Berberine ameliorates renal injury in streptozotocin-induced diabetic rats by suppression of both oxidative stress and aldose reductase

Background Berberine is one of the main constituents of Coptidis rhizoma （CR） and Cortex phellodendri. In this study, we investigated the beneficial effects of berberine on renal function and its possible mechanisms in rats with diabetic nephropathy （DN）.
Methods Male Wistar rats were divided into three groups： normal, diabetic model, and berberine treatment groups. Rats in the diabetic model and berberine treatment groups were induced to diabetes by intraperitonal injection with streptozotocin （STZ）. Glomerular area, glomerular volume, fasting blood glucose （FBG）, blood urea nitrogen （BUN）, serum creatinine （Cr） and urine protein for 24 hours （UP24h） were measured using commercially available kits. Meanwhile, the activity of superoxide dismutase （SOD）, content of malondialdehyde （MDA） in serum, activity of aldose reductase （AR） and the expression of AR mRNA and protein in kidney were detected by different methods.
Results The results showed that oral administration of berberine （200 mg·kg^-1·d^-1） significantly ameliorated the ratio of kidney weight to body weight. Glomerular area, glomerular volume, FBG, BUN, Cr and UP24h were significantly decreased in the berberine treatment group compared with the diabetic model group （P〈0.05）. Berberine treatment significantly increased serum SOD activity and decreased the content of MDA compared with diabetic model group （P 〈0.05）. AR activity as well as the expression of AR mRNA and protein in the kidney was markedly decreased in the berberine treatment group compared with diabetic model group （P 〈0.05）.
Conclusion These results suggested that berberine could ameliorate renal dysfunction in DN rats through controlling blood glucose, reduction of oxidative stress and inhibition of the activation of the polyol pathway.     

Dyslipidaemia among diabetic patients with ischemic stroke in a Chinese hospital

Background Dyslipidaemia is a potential independent The aim of this study was to investigate dyslipidaemia, with ischemic stroke in a Chinese hospital. risk factor for cerebrovascular disease in patients with diabetes. treatment and control of dyslipidaemia among diabetic patients Methods A total of 1046 type 2 diabetic patients were assigned to diabetes with （n=-522） and diabetes without stroke groups. The two groups were matched by gender, age and diabetes duration. Lipid and lipoprotein profile were measured. Serum level and control of lipids were assessed and classified according to American Diabetes Association （ADA） guidelines and an intensified low density lipoprotein-cholesterol （LDL-C） target recommended in Chinese dyslipidaemia control criteria. Results Diabetic patients suffering stroke displayed not only poorly-controlled lipid and lipoprotein profiles, including the significantly lower proportion of patients achieving intensified LDL-C target of 〈2.07 mmol/L （80 mg/dl）, and high density lipoprotein-cholesterol （HDL-C） target （14.4% vs 21.0%, P=0.005; 45.8% vs 51.9%, P=0.048 respectively）, but also less adherence to therapy prescribed for dyslipidaemia （30.8% vs 41.0%, P=0.001）, when compared with diabetic patients without stroke. For the diabetic women with stroke, situation of dyslipidaemia was worse, with significantly lower serum level of HDL-C and apoA1, higher LDL-C level and higher ratio of apoB/apoA1 when compared with diabetic counterparts without stroke. Conclusions Many diabetic patients with ischemic stroke remain uncontrolled for dyslipidaemia. Intensified LDL-C and overall lipid lowering clinical goals are potential precautions taken against ischemic stroke among diabetic patients in China.     

Changes in the expression of platelet-derived growth factor in astrocytes in diabetic rats with spinal cord injury

Background Prospective mortality studies in the United States revealed that the mortality was elevated in diabetics compared to normal individuals following chronic spinal cord injury （SCI）. Our study was conducted to investigate the levels of platelet-derived growth factor （PDGF） of astrocytes in SCI in streptozotocin （STZ）-induced diabetic rats. Methods Thirty male Sprague-Dawley （SD） rats were randomly divided into 3 groups： SCI group, diabetic SCI group, and sham operation control group. We employed STZ-induced diabetic SD rats and a weight-drop contusion SCI model. The rats were sacrificed on day 7 after the induction of SCI. Immunohistochemistry and Western blotting analysis were used to detect the PDGF expression level. Basso, Beattie and Bresnahan locomotor rating scale （BBB） was also used to evaluate the neurological recovery level of the rats. Results PDGF positive astrocyte numbers were significantly higher and PDGF staining was more intensive in astrocytes in the SCI group than in the diabetic SCI group （P〈0.05）. The diabetic SCI group showed a slower recovery of motor function with a lower BBB score 7 days after acute spinal injury. Conclusions PDGF is an important factor for the recovery of neurological function after acute spinal injury and hyperglycemia in diabetic rats could depress the expression of PDGF in injured spinal cord. This may help to explain the slower recovery and higher mortality in diabetics after SCI.     

Molecular mechanism of limbs’ postischemic revascularization improved by perindopril in diabetic rats

Background Currently, there are still divergent opinions about the mechanisms of the impaired neovascularization in diabetic subjects. Due to the remarkable therapeutic effect of angiotensin-converting enzyme inhibititors （ACEIs） on the reduction of blood pressure and the protection of target organs, the clinical application of this kind of drugs is very widespread. However, it is still not clear about the role and related molecular pathway of this kind of drugs in the limbs＇ postischemic revascularization. It is of major therapeutic importance to resolve these questions. This study aimed to investigate the reasons of the impaired angiogenesis in the hind limbs of rats with diabetic ischemia, the role and related molecular mechanisms of ACEI in postischemic revascularization.
Methods Hind limbs ischemia was induced in diabetic rats by right femoral artery excision. Diabetic rats were randomly allocated to one of the following treatments for 4 weeks： ACEI by perindopril; perindopril in combination with a nitric oxide synthase （NOS） inhibitor; perindopril in combination with bradykinin （BK）-B1 receptor （BIR） antagonist or saline. The differences of angiogenesis, the mRNA and protein expression of endothelial nitric oxide synthase （eNOS）, vascular endothelial growth factor （VEGF） and basic fibroblast （bFGF）, constitutive nitric oxide synthase （cNOS） activity and nitric oxide （NO） content were observed after treatment.
Results In non-ischemic hind limbs, no significant changes in capillary density, or the mRNA and protein expression of eNOS, VEGF and bFGF, or the NO content and the cNOS activity were observed among all groups. On the contrary, in ischemic hind limbs, the capillary density in diabetic rats decreased by 27% when compared with the control rats, so did the mRNA and protein expression of eNOS, VEGF and bFGF, or the NO content and the cNOS activity （P 〈0.05）. The capillary density was increased by 1.65-fold in the perindopril treatment group in reference to     

Effects of formaldehyde inhalation on lung of rats

To analyze protein changes in the lung of Wistar rats exposed to gaseous formaldehyde (FA) at 32-37 mg/m^3 for 4 h/day for 15 days using proteomics technique. Methods Lung samples were solubilized and separated by two-dimensional electrophoresis (2-DE), and gel patterns were scanned and analyzed for detection of differently expressed protein spots. These protein spots were identified by MALDI-TOF-MS and NCBInr protein database searching. Results Four proteins were altered significantly in 32-37 mg/m3 FA group, with 3 proteins up-regulated, 1 protein down-regulated. The 4 proteins were identified as aldose reductase, LIM protein, glyceraldehyde-3-phosphate dehydrogenase, and chloride intracellular channel 3. Conclusion The four proteins are related to cell proliferation induced by FA and defense reaction of anti-oxidation. Proteomics is a powerful tool in research of environmental health, and has prospects in search for protein markers for disease diagnosis and monitoring.     

Influence of neurotrophin-3 on Bcl-2 and Bax expressions in spinal cord injury of rats

Objective： To study the protective mechanisms of neurotrophin-3 （NT-3） on the spinal cord injury. Methods：Totally 105 SD rats were randomly divided into 3 groups： control group, experimental group and sham operation group. Rats from the former 2 groups were inflicted to animal model of acute spinal cord injury according to Allen＇s （WD） by situating a thin plastic tube in the subarachnoid space below the injury level for perfusion. Rats in experimental group received 20 ul NT-3 （200 ng） from the tube at 0, 4, 8, 12, 24 h and 3, 7 d after injury, and those in control group got an equal volume of normal saline at the same time. The animals in sham operation group only received opening vertebral plate and tube was put in subarachnoid space. The rats were sacrificed at 4, 8, 12, 24 h and 3, 7, 14 d post injury （n=5）. The expression levels of Bcl-2 and Bax proteins in spinal cord of rats were detected by immunohistochemistry assay. Results： The level of Bax protein in control group significantly increased as compared with those in sham operation group, and the peak reached at 8 h after spinal cord injury. The Bcl-2 proteins were always weakly positive. The Bax proteins in NT-3 group significantly decreased but the Bcl-2 proteins obviously increased as compared with those in control group. Conclusion： NT-3 can protect spinal cord from injury in vivo. One of the mechanisms is that NT-3 can inhibit abnormal expression of Pax protein, and increase the expression of Bcl-2 protein, then inhibit apoptosis after spinal cord injury.     

Inactivation of the Rho-ROCK signaling pathway to promote neurologic recovery after spinal cord injuries in rats

Background After injury,axonal regeneration of the adult central nervous system （CNS） is inhibited by myelin-derived growth-suppressing proteins.These axonal growth inhibitory proteins are mediated via activation of Rho,a small GTP-binding protein.The activated form of Rho,which is bound to GTP,is the direct activator of Rho kinase （ROCK） through serial downstream effector proteins to inhibit axonal regeneration.The objective of this study was to observe the therapeutic effect of inactivation of the Rho-ROCK signaling pathway to promote neurologic recovery after spinal cord injuries in rats.Methods One hundred and twenty adult female Sprague-Dawley rats were randomly divided into three groups.Laminectomies alone were conducted in 40 rats in the sham group.Laminectomies and spinal cord transections were performed in 40 rats in the control group （treated with normal saline administered intraperitoneally）.Laminectomies and spinal cord transections were performed in 40 rats in the fasudil-treated group （treated with fasudil administered intraperitoneally）.Neurologic recovery was evaluated before surgery and 3 days,and 1,2,3,and 4 weeks after surgery using the Basso-Beattie-Bresnahan （BBB） scale of hind limb movement.At the same time,the expression of RhoA mRNA was determined with RT-PCR.Histopathologic examinations and immunofiuorescence staining of NF were performed 1 month after surgery.Results Compared with the control group,the BBB scores of the fasudil-treated group were significantly increased and the expression of RhoA mRNA was significantly decreased.In the fasudil-treated group,a large number of NF-positive regenerating fibers was observed; some fibers crossed the slit of the lesion.Conclusion Inactivation of the Rho-ROCK signaling pathway promotes CNS axonal regeneration and neurologic recovery after spinal cord injuries in rats.     

Effect of the regimen of "Gaoshan Hongjingtian" on mechanism of Poly (ADP-ribose) polymerase regulation of nuclear factor kappa B in the experimental diabetic retinopathy

Background Poly (ADP-ribose) polymerase (PARP) plays an important role in the death of retinal capillary cells in diabetic retinopathy (DR), partly via its regulation of nuclear factor kappa B (NF-κB). The current study investigated the effect of the regimen of "Gaoshan Hongjingtian" on the mechanism of PARP regulation of NF-κB, and demonstrated the possible impact of the regimen of "Gaoshan Hongjingtian" and rhodiola sachalinensis on diabetic retinopathy. Methods Wistar rats were made diabetic with streptozotocin, then, were assigned to three groups. After 2 months, these diabetic rats treated with rhodiola sachalinensis or the regimen of “Gaoshan Hongjingtian”, or untreated. Analyses of expression levels of PARP, NF-κB and intercellular adhesion molecule-1 (ICAM-1) on the retinas of rats in different groups were performed by Western blotting and immunohistochemical assays, and mRNA levels of NF-κB and ICAM-1were determined by real-time PCR. In addition, the basement membranes of capillaries in the rats’ retinas were observed by using electron microscopy, and diabetes-induced capillary degeneration (ghost pericytes and acellular capillaries) were quantitated. Results From the third month after the injection, the diabetic rats were given daily with the regimen of “Gaoshan Hongjingtian”, rhodiola sachalinensis or tap water separately. The diabetic rats failed to gain weight when compared with normal age-matched ones, whereas their glycated hemoglobin levels were significantly increased. After 5 months, the mRNA levels of NF-κB and ICAM-1, the protein expression of PARP, NF-κB, and ICAM-1 were significantly increased in the retinas of diabetic rats in untreated group, compared to the nondiabetic controls. After 8 months, the number of degenerated retinal capillaries (ghost pericytes and acellular capillaries) was significantly increased in the diabetic rats in untreated group, compared to normal age-matched rats. The regimen of “Gaoshan Hongjingtian” and rhodiola sachalinensis inhibited diabetes-induced up-expression of PARP, NF-κB, and ICAM-1 in the retinas of diabetic rats with diabetic duration of 5 months. Treatment using the regimen of “Gaoshan Hongjingtian” and rhodiola sachalinensis significangtly inhibited increases in the number of acellular capillaries and pericyte ghosts and suppressed basement membrane thickening in the retinas of rats with diabetes for 8 months, as compared to control diabetic rats. Conclusions These results indicate that PARP plays a role in the pathogenesis of diabetic retinopathy. Rhodiola sachalinensis and the regimen of “Gaoshan Hongjingtian” may have acted on the mechanism of PARP regulation of NF-κB, which suppressed the expression of NF-κB and ICAM-1, and led to inhibition of retinal capillary degeneration.     

葡萄子原花青素对糖尿病大鼠肾保护作用机制的研究

目的 研究葡萄子原花青素（GSPE）对糖尿病大鼠肾保护作用的分子生物学机制。方法 雄性Wistar大鼠尾静脉注射0.1%链脲佐菌素（STZ）建立糖尿病大鼠模型，成模后随机分为糖尿病组（DM组）和糖尿病GSPE治疗组［GSPE组，GSPE 250mg/(kg·d)］，另设正常对照组（C组）。24周后采血测定空腹血糖（FPG）、尿素氮（BUN）、肌酐（SCr）、糖基化血红蛋白（HbA1c），晚期糖基化终末产物（AGEs），并观察糖尿病大鼠肾脏病理改变。应用双向凝胶电泳（2-DE）和质谱鉴定方法比较糖尿病大鼠肾组织蛋白质的差异表达。结果 GSPE组AGEs、BUN、SCr水平较DM组降低（P＜0.05），GSPE组肾组织病理改变较DM组改善。DM组与C组比较差异表达的蛋白点25个，其中蛋白SSP No.1252经鉴定为谷胱甘肽转硫酶Mu亚型（GSTM）；GSTM在DM组表达较C组上调，在GSPE组治疗后回调（P＜0.05）。结论GSPE可能通过下调GSTM表达而起肾保护作用。     

葡萄子原花青素对糖尿病大鼠心肌超微结构的影响

目的：观察葡萄子原花青素（grape seed proanthocyanidin extracts,GSPE）对链脲佐菌素（streptozotocin,STZ）糖尿病大鼠血浆糖基化终末产物（advanced glycation end products，AGEs）、心肌超微结构的影响；探讨GSPE对STZ糖尿病大鼠心肌的保护作用。方法：雄性Wistar大鼠尾静脉注射0.1%STZ以建立糖尿病模型，成模后随机分为2组，糖尿病对照组（DM1组，n=8）和糖尿病GSPE治疗组（GSPE250?mg/(kg·d)，DM2组,n=12）,另设2组，正常对照组（C1组,n=10）和正常GSPE治疗组（C2组,n=10）。24周后采血测血糖、糖化血红蛋白（glycosylated hemoglobin, HbA1c）、AGEs，电镜观察心肌超微结构变化。结果：DM2组AGEs较DM1组明显降低(t=2.792, P=0.02)；DM1组肌原纤维和线粒体排列紊乱，经GSPE治疗后DM2组明显减轻。结论：GSPE能够抑制STZ糖尿病大鼠非酶糖基化反应，对其心脏超微结构有一定保护作用。     

葡萄子原花青素对糖尿病肾病大鼠非酶糖基化终产物和骨形态蛋白7表达的影响

   目的   研究葡萄子原花青素（GSPE）对糖尿病大鼠非酶糖基化终产物（AGEs）、肾组织结缔组织生长因子（CTGF）及骨形态蛋白7（BMP 7）表达的影响。  方法   将45只链脲佐菌素（STZ）诱导的糖尿病大鼠模型随机分为糖尿病组（DM组,n=15只）、GSPE小剂量［250mg/（kg·d）］治疗组（T1组,n=15只）和大剂量［500mg/（kg·d）］治疗组（T2组,n=15只）,另以15只正常大鼠作为对照组（C组）,15只正常大鼠给予GSPE 250mg/（kg·d）作为正常治疗组（CT组）。于24周末检测各组大鼠血糖、血清AGEs、血压、24?h尿蛋白定量、血肌酐（Scr）、尿肌酐（Ucr）、肾重/体重水平。以光镜PAS染色及电镜观察肾脏病理改变。用RT PCR、Western blot方法及免疫组化方法检测肾组织中CTGF、BMP-7mRNA及蛋白表达水平的改变。  结果   与C组相比,DM组血清AGEs、血压、24h尿蛋白定量、内生肌酐清除率（Ccr）、肾重/体重均显著升高（P＜0.01）,肾病理改变加重,肾组织CTGF mRNA及蛋白表达增加（P＜0.01）,而BMP-7mRNA及蛋白降低（P＜0.05）。与DM组相比,T1组和T2组血清AGEs、血压、24h尿蛋白定量、Ccr和肾重/体重显著降低（P＜0.05或P＜0.01）,病理改变减轻, BMP-7mRNA及蛋白表达水平升高(P＜0.05或P＜0.01）,而CTGF mRNA及蛋白显著降低（P＜0.01）。T1组与T2组之间相比,Ccr、肾重/体重水平、CTGF mRNA及蛋白差异有统计学意义（P＜0.05或P＜0.01）。   结论    GSPE可以减轻糖尿病大鼠蛋白尿、改善肾脏病理,对其肾脏有明显保护作用,其机制与降低血清AGEs、抑制肾组织CTGF过高表达、上调BMP-7表达有关。     

吡哆胺对糖尿病大鼠视网膜晚期糖基化终产物及其受体的影响

目的观察吡哆胺对糖尿病大鼠视网膜晚期糖基化终产物(AGEs)的含量和其受体(RAGE)表达的影响,探讨吡哆胺对糖尿病视网膜病的防治作用。方法 SD大鼠随机分为正常对照组(NC组)、糖尿病组(DM组)、吡哆胺治疗组(PM组)和糖尿病氨基胍治疗对照组(AG组),建立链脲佐菌素(STZ)糖尿病大鼠模型,每周测体质量和血糖。各组于治疗4周和12周取材,酶联免疫吸附(ELISA)法定量检测大鼠血清、视网膜中AGEs,12周时用免疫组织化学半定量检测视网膜RAGE的表达。结果 PM组、AG组与DM组比较,血糖差别无统计学意义;4周和12周时的PM组和AG组的大鼠血清和视网膜AGEs均低于DM组(P<0.05);12周时PM组和AG组视网膜RAGE表达低于DM组(P<0.01)。结论吡哆胺无明显降糖作用,但可通过减少AGEs堆积,降低RAGE表达,对糖尿病大鼠视网膜具有一定的保护作用。     

Enalapril对实验性糖尿病大鼠肾脏的保护作用机理研究

目的　研究血管紧张素转换酶抑制剂 Enalapril对糖尿病的肾病治疗作用机理。方法　以Enalapril治疗实验性糖尿病大鼠 ,并将正常组、糖尿病对照组及治疗组尿蛋白水平及肾组织转化生长因子 β、糖基化终末产物含量进行比较。结果　 Enalapril治疗组大鼠肾组织转化生长因子 β及糖基化终末产物含量与糖尿病对照组相比无下降。结论　 Enalapril的肾脏保护作用并非通过抑制肾组织转化生长因子 β上调或糖基化终末产物积聚     

Enalapril对实验性糖尿病大鼠肾脏的保护作用机理研究

目的 研究血管紧张素转换酶抑制剂Enalapril对糖尿病的肾病治疗作用机理，方法 以Enalapril治疗实验性糖尿病大鼠，并将正常组、糖尿病对照组及治疗组尿蛋白水平及肾组织转化生长因子β-糖基化终末产物含量进行比较，结果 Enalapril治疗组大鼠肾组织转化生长因子β及糖基化终末产物含量与糖尿病对照组相比无下降。结论 Enalapril的肾脏保护作用并非通过抑制肾组织转化生长因子β上调或糖基化终末产物积聚。     

菩人丹超微粉对STZ诱导糖尿病大鼠视网膜病变的保护作用及其对NF-κB信号通路的影响

目的：探讨菩人丹超微粉（PRD）对糖尿病大鼠视网膜的保护作用及其对核因子κB （NF-κB）信号通路的影响,并阐明其作用机制。方法：40只Wistar大鼠随机分为正常对照组、模型组、低剂量PRD组和高剂量PRD组。给药3个月后,测定各组大鼠血糖水平,RT-PCR法检测大鼠视网膜组织中血管内皮生长因子（VEGF）和血管生成素2（Ang-2） mRNA表达水平,Western blotting法检测大鼠视网膜组织中晚期糖基化终末产物（AGEs）、晚期糖基化终末产物受体（RAGE）、NF-κB、VEGF和Ang-2蛋白表达水平。结果：与正常对照组比较,模型组大鼠血糖水平及视网膜组织中VEGF、Ang-2 mRNA表达水平和AGEs、RAGE、NF-κB、VEGF、Ang-2蛋白表达水平明显升高（P<0.05）;与模型组比较,低和高剂量PRD组大鼠血糖水平及视网膜组织中VEGF、Ang-2 mRNA表达水平和AGEs、RAGE、NF-κB、VEGF、Ang-2蛋白表达水平明显降低（P<0.05）。结论：PRD可能通过特异性阻断AGEs/RAGE/NF-κB信号通路对糖尿病大鼠视网膜起保护作用。     

玉竹乙醇提取物和分离部位对糖尿病大鼠肾脏的保护作用

目的探讨玉竹乙醇提取物和分离部位对糖尿病大鼠肾脏的保护作用。方法单次ip链脲佐菌素(STZ)60mg/kg建立实验性糖尿病大鼠模型,分别ig给予玉竹乙醇提取物和三氯甲烷、正丁醇分离部位。给药80d后测定血清肌酐(Cr)、尿素(Ur)、糖化血红蛋白(GHb)、肾皮质蛋白质非酶糖基化终末产物(AGEs)、尿白蛋白(UAL)排泄率,并观察肾组织病理学改变。结果玉竹乙醇提取物和三氯甲烷分离部位降低糖尿病大鼠血中GHb水平和UAL排泄率,抑制肾皮质AGEs的形成,同时改善肾脏病理改变;正丁醇分离部位降低UAL排泄率。结论玉竹乙醇提取物和三氯甲烷分离部位对糖尿病大鼠肾脏保护作用机制可能与抑制AGEs形成有关。     

糖尿病大鼠视网膜中NGF的动态表达及巴曲酶对其的影响

目的探讨神经生长因子（NGF）在糖尿病大鼠视网膜中的动态变化规律，初步证实巴曲酶对NGF的影响并探讨其机制，为临床上治疗糖尿病视网膜病变（DR）提供理论依据。方法将大鼠腹腔注射链脲佐菌素制作实验性糖尿病模型，再分别于成模后2个月和3个月时腹腔注射巴曲酶进行干预。通过免疫组织化学和原位杂交双重检测NGF在视网膜中的表达。结果糖尿病（DM）造模后2个月时视网膜中NGF的含量明显减少，且随时间变化有统计学差异，而巴曲酶治疗后NGF的表达明显增加。结论DR大鼠视网膜中NGF表达减少可能参与DR的发病机制。巴曲酶对DR有保护作用，其机制可能包括对NGF的调节。     

黄芪多糖对2型糖尿病早期大鼠视网膜Muller细胞Kir2.1表达的影响

目的:探讨黄芪多糖对链脲佐菌素(STZ)诱导的2型糖尿病大鼠早期视网膜Muller细胞Kir2.1表达的影响。方法:雄性SPF级SD大鼠随机分为:正常对照组(C组,n=10),黄芪多糖对照组(CA组,n=10),饲以正常饲料;通过高脂饮食加小剂量STZ诱导复制2型糖尿病大鼠模型,将血糖>13.9 mmol/L者随机分为糖尿病组(DM组,n=8)及黄芪多糖治疗组(DA组,n=8)。治疗前后观察血糖、口服葡萄糖耐量变化。从4组大鼠视网膜提取总mRNA,逆转录聚合酶链反应(RT-PCR)方法检测Kir2.1 mRNA的表达。结果:DM组血糖显著高于C组,同时伴有明显的糖耐量下降(P<0.01),经黄芪多糖治疗8周后,DA组血糖降低,与DM组比较糖耐量改善(P<0.01)。RT-PCR扩增的Kir2.1 cDNA产物在DM组表达比在C组下降,而在CA组表达较DM上升(P<0.05),但在C组与CA组中未出现这种显著性的改变(P>0.05)。结论:黄芪多糖能够降低血糖,糖尿病大鼠早期视网膜Muller细胞Kir2.1蛋白表达下降,而黄芪多糖对于逆转这一早期的改变可能起到一定作用,从而起到减少糖尿病视网膜病变发病率的作用。