GAP-43在Ⅰ型糖尿病早期大鼠边缘系统的表达及意义

目的:观察链脲佐菌素(streptozotocin,STZ)诱导的糖尿病大鼠早期边缘系统的扣带回、背侧丘脑、下丘脑和杏仁体中生长相关蛋白(growth-associated protein,GAP-43)的变化,探讨GAP-43在糖尿病脑病发病中的重要作用。方法:SD雄性大鼠20只随机分为正常组及糖尿病组,用STZ复制糖尿病动物模型,饲养7 d后测血糖,4周后应用免疫组织化学方法观察糖尿病组和正常组大鼠的扣带回、背侧丘脑、下丘脑和杏仁体GAP-43的表达情况。结果:糖尿病组大鼠边缘系统的扣带回、背侧丘脑、下丘脑和杏仁体的GAP-43表达增高。结论:糖尿病大鼠早期边缘系统GAP-43表达增加,反映了神经组织对机体糖代谢紊乱的适应性改变过程,提示在糖尿病的早期已经发生了神经组织的改变。     

Beta-adrenergic receptors and adenylate cyclase activity in the parotid acinar cells from acute streptozotocin-induced diabetic rats

The changes in beta-adrenergic receptors and in adenylate cyclase (AC) activity were investigated in parotid glands from rats with acute diabetic mellitus (DM) induced by a single injection of streptozotocin (STZ, 80 mg/kg). The animals were divided into three groups: control rats, DM rats, and insulin-treated DM rats. Experiments were performed 7 days after the injection of STZ. Amylase and norepinephrine (NE) contents in parotid glands were markedly decreased in DM rats in comparison with control rats. The density of beta-adrenergic receptor decreased in DM rats, but its affinity for ligand was unaffected. The effect of GTP on isoprenaline (ISO)-stimulated adenylate cyclase (AC) activity significantly decreased in DM rats, but forskolin-stimulated AC activity was unaltered. In addition, diabetes induced the blunted response of AC activity to ISO. The changes in AC activity and in amylase content induced by diabetes were restored by insulin, but those in NE content and receptor density could not. These observations indicate that diabetes decreases NE and amylase contents, receptor density, and receptor-AC coupling in parotid gland, and that these changes would occur in the earlier stage of acute STZ-induced diabetic state.     

Effects of preventative application of metformin on bile acid metabolism in high fat-fed/streptozotocin-diabetic rats

Objective: This study was designed to investigate the effects of metformin on bile acid in type 2 diabetes mellitus (T2DM). Methods: In this study, we constructed a model of T2DM by a combination of high-fat diet (HFD) and low dose of streptozotocin (STZ) intraperitoneal injection. Blood samples by tail vein and eye angular vein were withdrawn before (time 0) and 30, 60, and 120 minutes after administration of glucose before STZ injection and once a week after diabetes induction, and were analyzed to evaluate the level of the fasting blood glucose and fasting insulin using glucometer. Triglyceride, low density lipoprotein cholesterin, high density lipoprotein cholesterin were detected by automatic biochemical analyzers. Total cholesterol and total bile acid (TBA) were analyzed using ELISA kits. Results: Before STZ injection, the TBA level in HFD group was significantly higher relative to that in standard diet (SD) group and there was a moderate reduction of the TBA level in early intervention (EI) group 6 week after metformin administration comparing with that in HFD group but was still higher than that of SD group. However, after STZ injection, the TBA level was significantly higher in DM rats relative to that in normal control (NC) rats and the TBA level in late intervention (LI) (19.92 μmol/L) and EI rats (42.97 μmol/L) with metformin administration was significantly higher comparing with that in DM rats. Conclusion: The effects of metformin in plasma glucose and lipid metabolism might be associated with bile acid metabolism.     

Differentiations of the effect of NMDA on the spatial learning of rats with 4 and 12 week diabetes mellitus

This study examines possible interactions between behavioral effects and influence of N-methyl-D-aspartate acid (NMDA) receptors in 4 and 12-week streptozotocin (STZ) induced diabetic rats. Effects of NMDA receptor agonist on spatial learning were tested in control groups of rats and in rats with 4 and 12 weeks diabetes mellitus (DM). Experimental diabetes was induced by a single intravenous injection of streptozotocin at a dose of 65 m/kg, dissolved in citrate buffer. We used the water maze task and examined the acquisition and the retrieval of spatial memory in rats. In our present experiments, we observed that DM had no significant influence on acquisition and retrieval in 4 week diabetic rats on Morris water maze, but impaired examined parameters in 12 week diabetic rats in this test. The NMDA receptor agonist did not influence acquisition but increased recall on water maze in 12 week streptozotocin diabetic rats.     

链佐霉素诱导糖尿病昆明鼠认知功能与高血糖的关系

目的:研究昆明鼠经链佐霉素诱导后,血糖升高与学习和记忆能力之间的相关性.方法:选取年龄、体重以及血糖接近的昆明小鼠,连续5d腹腔注射50 mg·kg-1链佐霉素建立糖尿病小鼠模型.经血糖仪测定尾静脉血糖含量,其中空腹血糖大于或等于11 mmol· L-1作为糖尿病模型合格小鼠.糖尿病小鼠(n=12)和正常小鼠(n=10)通过水迷宫实验和穿梭实验检测小鼠学习和记忆能力.病理组织学检测糖尿病小鼠肾脏、胰腺和主动脉等器官病理改变.结果:与对照组相比,链佐霉素处理组小鼠饮食、饮水量显著提高并伴随体重下降(P＜0.05).4周后,糖尿病小鼠和正常小鼠的学习和记忆能力并没有显著差别(P＞0.05).但是12周后,糖尿病小鼠行动迟缓,比正常组小鼠定位巡航和空间探索能力均下降(P＜0.05).讨论:持续12周的高血糖状态并未导致STZ诱导的糖尿病小鼠出现认知功能障碍,有关糖尿病和认知功能之间的关系需要进一步进行研究.     

Low carbohydrate ketogenic diet prevents the induction of diabetes using streptozotocin in rats

Diabetes continues to be an overwhelmingly prevalent endocrine disorder that leads to several micro- and macrocomplications. It has been widely accepted that changes in dietary habits could induce or prevent the onset of diabetes. It is shown that low carbohydrate ketogenic diet (LCKD) is effective in the amelioration of many of the deleterious consequences of diabetes. However, its role in preventing the onset of diabetes is not understood. Therefore, this study is focused on the effect of LCKD in preventing the induction of diabetes using streptozotocin (STZ) in rats by biochemical and histological methods. Forty-two Wistar rats weighing 150-250 g were used in this study. The animals were divided into three groups: normal diet (ND), low carbohydrate ketogenic diet (LCKD), and high carbohydrate diet (HCD). Specific diets ad libitum were given to each group of animals for a period of 8 weeks. Each group was further subdivided into normal control, sham control and diabetic groups. Animals in the diabetic group were given a single intraperitoneal injection of STZ (55 mg/kg). All the animals were sacrificed 4 weeks after the injection of STZ. Daily measurements of food and water intake as well as weekly measurement of body weight were taken during the whole 12 weeks of the experiment. After injecting with STZ, the blood glucose level of all the groups increased significantly except for the group fed on LCKD (p value<0.01). Also, food intake, water intake and urine output were significantly increased in all groups except for the LCKD group (p value<0.01). There was also a significant decrease in the weight gain of the animals that were fed on a LCKD as compared to other groups (p value<0.05). Although, substantial decrease in the number of β cells was noticed in diabetic rats, there were no change in the number of β cells in the LCKD treated diabetic animals as compared to LCKD control group. The results presented in this study, therefore, suggests that LCKD prevents the development of diabetes using streptozotocin in rats.     

Streptozotocin-induced type 1 and 2 diabetes in rodents: a model for studying diabetic cardiac autonomic neuropathy

BackgroundSeveral animal models are continually being developed to study diabetic complication. Several conflicting regimen for diabetes induction exist in the literature with varying dose strength and regimen for different study interest in diabetes. This study aims to show the effect of high dose streptozotocin (STZ) on the one hand compared with multiple low doses after high fat diet induction on diabetic cardiac autonomic neuropathy (DCAN).MethodologyEighty-four Wistar rats were used to demonstrate DCAN induction using 2 approaches one for T1DM (STZ 50mg/kg) and the other for T2DM (HFD for 8 weeks with STZ 25mg/Kg daily for five days). DCAN features were assessed using invasive biomarkers, histology patterns and cardiac nerve densities.ResultsDiabetes induction rate was 76% and 89% in T1DM and T2DM model respectively. T1DM group had significant weight loss, reduced c-peptide, and insulin level post induction. The T2DM additionally showed significantly higher total cholesterol and Homeostatic model assessment (HOMA) compared with control. Serum levels of catecholamine, choactase, nerve growth factor and cardiac nerve density confirms development of DCAN.ConclusionHigh single dose of STZ and HFD with multiple low doses of STZ may be recommended for DCAN study in T1DM and T2DM rat model respectively.     

糖尿病大鼠肾小管骨调素和p38MAPK表达的动态研究

目的:动态观察骨调素（OPN）在链脲佐菌素（STZ）诱导的糖尿病大鼠肾小管的表达，探讨它与p38丝裂原活化蛋白激酶（p38MAPK）、核转录因子-κB（NF-κB）及肾损害之间的关系。方法：雄性SD大鼠，注射STZ诱导糖尿病（DM），随机分成5组，每组分别设鼠龄匹配的正常对照组。免疫组化方法检测肾小管OPN、p38MAPK、NF-κB及纤连蛋白（FN）的表达；Western印迹法检测肾皮质OPN和p38MAPK蛋白质水平；生化方法测定血糖、血肌酐及24 h尿蛋白量；光镜检查肾组织的形态改变。结果： Western印迹和免疫组化检测发现糖尿病3 d大鼠肾组织p38MAPK和DM 7 d OPN的表达增多，并随病程发展而增加，与正常对照组比较有显著差异（P<0.01）。DM 4周，肾小管OPN的表达与p38MAPK、NF-κB、FN表达及蛋白尿呈显著正相关。结论： 糖尿病大鼠肾小管OPN表达增加参与了糖尿病肾小管间质损害的发病机制；肾小管p38MAPK可能介导了DM状态时NF-κB的表达，进而调节OPN的表达增多。     

Preventive effect of zinc acexamate administration in streptozotocin-diabetic rats: Restoration of bone loss

The preventive effect of zinc compounds on bone loss in streptozotocin (STZ)-diabetic rats was investigated. Rats received a single subcutaneous administration of STZ (6.0 mg/100 g body weight), and 7, 14 or 21 days later the animals were sacrificed by bleeding. STZ administration caused a significant decrease in body weight and a significant increase in serum glucose and triglyceride levels, indicating diabetic condition. Femoral-diaphyseal and -metaphyseal alkaline phosphatase activity, calcium and deoxyribonucleic acid (DNA) contents were significantly decreased by STZ administration, showing that diabetic condition causes bone loss. Zinc sulfate (2.5 mg Zn/100 g) or zinc acexamate (2.5 mg Zn/100 g) was orally administered once daily for 14 days to rats received a single subcutaneous administration of STZ (6.0 mg/100 g). STZ administration-induced increase in serum glucose and triglyceride levels and decrease in body weight, femoral-diaphyseal and -metaphyseal alkaline phosphatase activity, DNA and calcium contents were significantly prevented by the administration of zinc acexamate. The preventive effect of zinc sulfate on bone components was not seen. The present results demonstrate that the administration of zinc acexamate has a preventive effect on bone loss in STZ-diabetic rats in vivo.     

葡萄籽原花青素通过Nrf2调节糖尿病大鼠肾组织GSTM的表达

目的: 研究葡萄籽原花青素(GSP)对糖尿病大鼠肾保护作用的分子生物学机制,为GSP治疗糖尿病肾病提供实验依据。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GSP治疗组(GSP组,GSP 250 mg·kg^-1·d^-1),另设正常对照组(C组)。观察24周后测量大鼠体重、收缩压、肾重/体重和24 h尿蛋白定量;采血测定空腹血糖(FPG)、尿素氮(BUN)、肌酐(SCr)和糖基化血红蛋白(HbA1c);观察糖尿病大鼠肾脏病理改变,并应用Western blotting和免疫组化法测定肾组织谷胱甘肽S-转移酶μ亚型(GSTM)和核因子E2相关因子2(Nrf2)的表达。结果: 实验开始时3组大鼠体重无明显差异(P>0.05),24周时DM组大鼠较C组大鼠体重显著下降(P<0.01),治疗后GSP组大鼠体重较DM组增加,但无显著差异(P>0.05)。第24周时DM组大鼠与C组相比较,收缩压、FPG、HbA1c、肾重/体重、24 h尿蛋白定量、BUN和SCr水平显著升高(P<0.01)。治疗后GSP组大鼠与DM组比较FPG和HbA1c水平降低,但无显著差异(P>0.05),收缩压、24 h尿蛋白定量和肾重/体重显著降低,(P<0.01),BUN和SCr水平显著降低(P<0.05)。GSP组肾组织病理改变较DM组改善。GSTM和Nrf2表达在DM组表达较C组上调,在GSP组治疗后回调(P<0.05)。结论: GSP可能通过Nrf2下调GSTM表达而起肾保护作用。     

姜黄素对糖尿病大鼠心肌的保护作用*

 目的： 研究姜黄素对糖尿病大鼠心肌的保护作用及可能机制。方法: 雄性Wistar大鼠75只,随机抽取10只大鼠作为正常对照组,其余65只大鼠给予高糖高脂饮食喂养8周后腹腔注射链脲佐菌素40 mg/kg,给药72 h和7 d空腹血糖≥11.6 mmol/L为糖尿病模型成功大鼠。糖尿病大鼠随机分为糖尿病心肌病组、姜黄素小剂量治疗组和大剂量治疗组。测定心肌谷胱甘肽过氧化物酶（GSH-Px）活性和丙二醛（MDA）含量,酶联免疫吸附试验检测血清心肌钙蛋白I（cTnI）的变化,Western blotting检测蛋白激酶C（PKC）蛋白表达。结果: 姜黄素治疗后可明显改善糖尿病所致的动物体重下降和空腹血糖升高,抑制心肌中MDA的产生并升高GSH-Px活性,减少血清中cTnI的释放,下调心肌组织PKC蛋白表达。结论: 姜黄素对大鼠糖尿病心肌病具有保护作用,其机制可能与抑制氧化应激有关。     

Alterations in the proangiogenic functions of adipose tissue-derived stromal cells isolated from diabetic rats

Cardiovascular complications in diabetic patients have been reported to be related to the impaired proangiogenic actions of endothelial progenitor cells. In this study, we investigated the functions of adipose tissue-derived stromal cells (ASCs) in diabetes. We induced type I diabetes in rats by a intraperitoneal injection of 60 mg/kg of streptozotocin (STZ) and type II diabetes by the combined treatment of high fat diet and 45 mg/kg of STZ. Rat ASCs (rASCs) isolated from the adipose tissues in the interscapular and abdominal region of type I or type II diabetic rats showed lower proliferating ability than those of control rats. Diabetic rASCs showed lower blood flow recovery than those of control rats in a hindlimb ischemia model of nude mouse. When ASCs isolated from rat and human were exposed to high glucose concentrations, their proliferating abilities and improved blood flow in a hindlimb ischemia model were compromised, compared with ASCs that were maintained at control glucose concentrations. However, the same concentrations of mannitol did not affect these characteristics. Exposure of human ASCs (hASCs) to high glucose concentrations increased reactive oxygen species (ROS) production, and the addition of ROS scavengers [N-acetylcysteine (NAC) or catalase] to high glucose media partially decreased the high glucose-induced inhibitory effect on proliferating ability in hASCs. However, hASCs treated with high glucose medium for 6 days showed lower proliferation in control culture medium, which was not recovered by the addition of NAC or catalase. These data indicate that ASCs isolated from diabetic rats and exposed at high concentration of glucose have an impaired proangiogenic action and that the functional impairment is partly due to ROS generated by chronic exposure to high glucose concentrations.     

Potential therapeutic role of melatonin on STZ-induced diabetic central neuropathy: A biochemical,histopathological, immunohistochemical and ultrastructural study

The aim of the present study was to assess the therapeutic potential of melatonin (Mel) in diabetic central neuropathy in a rat model of streptozotocin (STZ)-induced diabetes. The rats were injected with 60?mg/kg STZ and diabetes was confirmed by blood glucose levels (BGL) ≥ 250?mg/dL. Mel treatment (50?mg/kg) was started 72?h before the STZ injection and continued for 45 days. In addition, normal control, vehicle (5% ethanol) control, and Mel-treated non-diabetic control were also included. STZ induced a diabetic phenotype with persistent hyperglycemia and elevated oxidative stress in the brain, liver, and kidneys compared to the control groups. In addition, the diabetic rats showed severe β-cell necrosis with reduced insulin levels, cerebral neuronopathy, myelinopathy, axonopathy, microglial and astroglial activation, and vascular damage. While Mel treatment did not prevent the development of STZ-induced diabetes mellitus and had no significant effect on the BGLs of the diabetic rats, it significantly ameliorated the diabetes-induced oxidative stress and neurodegeneration. Taken together, Mel showed potent therapeutic effects against the neurological complications of hyperglycemia and therefore can be used to treat diabetic neuropathy.     

Platelet-rich plasma improves impaired glucose hemostasis,disrupted insulin secretion,and pancreatic oxidative stress in streptozotocin-induced diabetic rat

Abstract

Our study aimed to investigate the effects of platelet-rich plasma (PRP) on impaired glucose homeostasis, disrupted islet insulin secretion, and pancreatic oxidative status in streptozotocin (STZ)-diabetic rats. A total of 64 Sprague-Dawley male were randomized to four groups including controls, diabetes, control-PRP, and diabetes-PRP. The rats received the PRP (0.5?ml/kg, SC injection) twice weekly for 4 weeks. Plasma glucose and insulin levels, pancreatic oxidative stress markers and islet insulin secretion and content were measured. Compared with the control group, in the diabetic group, increased plasma glucose and malondialdehyde (MDA) levels and decreased plasma insulin level, islet insulin secretion, pancreatic superoxide dismutase (SOD), and catalase activities were observed. PRP treatment significantly reduced plasma glucose and MDA levels and enhanced plasma insulin, antioxidant enzyme activity, islet insulin secretion, and content in the diabetic rats. These findings showed that PRP can improve pancreatic islet insulin secretion, pancreatic oxidative stress and regulate plasma insulin and glucose levels in diabetic rats.     

Alteration in serum and bone component findings induced in streptozotocin-diabetic rats is restored by zinc acexamate

The effect of zinc acexamate in streptozotocin (STZ)-induced diabetic rats was investigated. Rats received a single subcutaneous administration of STZ (6.0 mg/100 g body weight), and the animals were orally administered once daily for 14 days with zinc acexamate (2.5, 5 or 10 mg/100 g body weight). The administration of STZ caused a significant increase in serum glucose, triglyceride and calcium levels and a significant decrease in body weight, serum zinc and inorganic phosphorus levels, indicating diabetic condition. Moreover, calcium content, alkaline phosphatase activity and deoxyribonucleic acid (DNA) content in the femoral-diaphyseal and -metaphyseal tissues were significantly reduced in STZ-diabetic rats. The change in these serum and bone components of STZ-diabetic rats was significantly restored by the oral administration of zinc acexamate (2.5, 5 or 10 mg Zn/100 g body weight). The restoration of bone components was not seen by the oral administration of zinc sulfate (2.5 mg Zn/100 g) for 14 days. Moreover, when the femoral-diaphyseal and -metaphyseal tissues obtained at 14 days after STZ administration were cultured for 48 h in a medium containing either vehicle or zinc acexamate (10(-5) M), the femoral calcium content and alkaline phosphatase activity were significantly increased in vitro. The effect of zinc acexamate was completely abolished in the presence of cycloheximide (10(-6) M), an inhibitor of protein synthesis. The present study demonstrates that the oral administration of zinc acexamate has a preventive effect on STZ-induced diabetic condition in rats, and that it can restorate bone loss of STZ-induced diabetes in vivo.     

Effect of C-peptide administration on whole body glucose utilization in STZ-induced diabetic rats

Recent studies suggest that C-peptide stimulates glucose transport in isolated skeletal muscle. In order to determine the effect of C-peptide on whole body glucose utilization, streptozotocin (60 mg kg^-1) (STZ)-induced diabetic and normal rats were studied using the euglycaemic clamp procedure and continuous infusion of somatostatin (1.0 μg kg^-1 min^-1) in pentobarbital-anaesthetized rats. Plasma insulin levels during the 6.0- and 30.0-mU kg^-1 min^-1 insulin infusions rose to 70–90 μU mL^-1 and 500–700 μU mL^-1, respectively. Blood glucose concentrations were clamped at 7.5–7.9 mmol L^-1 in the diabetic rats and at basal levels or 7.7 mmol L^-1 in the non-diabetic (normal) rats. Biosynthetic human C-peptide (0.5 nmol kg^-1 min^-1) was infused in 12 diabetic and 11 normal rats, resulting in concentrations of 26–41 nmol L^-1. The metabolic clearance rate of glucose (MCR) for the diabetic rats receiving C-peptide (12.0±1.0 mL kg^-1 min^-1) was significantly (P<0.01) higher than that in the diabetic rats given saline (6.3±0.7 mL kg^-1 min^-1) or a randomly scrambled C-peptide (7.8±1.3 mL kg^-1 min^-1) at low-dose insulin infusion but not at the high-dose insulin infusion. In normal rats C-peptide did not significantly increase the MCR for glucose. These results thus demonstrate that C-peptide has the capacity to increase glucose utilization in STZ-induced diabetic rats.     

Hypoglycaemic and Biochemical Properties of Cnestis Ferruginea

Increasing incidences of diabetes in Africa has prompted the search for safe and readily available alternative herbal remedies for the treatment of diabetes mellitus. Cnestis ferruginea was extracted with methanol and ethylacetate and the extracts obtained were tested for hypoglycaemic activities in streptozotocin (STZ)-induced diabetic rats and mice. The extracts (250mg/kg body weight) were administered orally for 10 consecutive days to STZ-induced diabetic rats while a single dose (250mg/kg body weight) of the extracts were administered to STZ-induced diabetic mice. Fasting blood glucose (FBG) levels were determined in the two groups of animals after extract administration. There was significant reduction in FBG (P< 0.005) by MCF and ECF within 4 hrs of extract administration in a time- dependent manner. Furthermore, administration of MCF and ECF for 10 days significantly lowered FBG in STZ diabetic rats (P<0.005) by 74% and 68%, respectively, whereas, glibenclamide - a standard antidiabetic drug reduced FBG by 60%. The levels of serum creatinine, urea, triglyceride, total cholesterol, total protein and level of lipid peroxidation were also evaluated. The extracts reduced significantly (P<0.005) the elevated levels of serum ALT and AST in diabetic treated rats. Similarly, both extracts significantly lowered (P<0.005) the levels of serum creatinine, urea, total cholesterol, triglyceride and thiobarbituric acid reactive species (TBARS).These results suggest that Cnestis ferruginea leaves contain a highly potent hypoglycaemic principle and could be a potential source for isolation of new orally active antihyperglycaemic compounds for attenuating secondary complications of diabetes such as atherosclerosis, liver and renal dysfunction.     

米诺环素对糖尿病大鼠脊髓小胶质细胞极化的影响

目的:研究米诺环素对糖尿病大鼠脊髓小胶质细胞极化的影响。方法:27只成年雄性SD大鼠分为对照组(control)、糖尿病组(DM)、米诺环素处理组(minocyline),利用腹腔注射链脲菌素(STZ)方法制备糖尿病大鼠模型,检测大鼠的血糖及体重变化,免疫荧光染色检测大鼠脊髓Iba-1的表达,酶联免疫吸附试验(ELISA)检测大鼠脊髓肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)、转化生长因子β(TGF-β)和白细胞介素10(IL-10)的水平变化,Western Blot检测大鼠脊髓CD68、精氨酸酶-1(Arg-1)、髓鞘相关糖蛋白(MAG)和髓鞘碱性蛋白(MBP)的表达变化。结果:STZ注射成功制备了糖尿病大鼠模型;免疫组化染色显示糖尿病模型大鼠脊髓Iba-1阳性细胞增多;ELISA检测结果显示糖尿病组大鼠脊髓组织中M1型小胶质细胞特异性细胞因子(TNF-α和IL-6)水平增加,米诺环素处理组大鼠脊髓组织中M2型小胶质细胞特异性细胞因子(TGF-β和IL-10)水平增加;Western Blot结果显示STZ组大鼠脊髓CD68表达上调,MAG和MBP表达降低,而米诺环素治疗组Arg-1、MAG和MBP表达均增加。结论:糖尿病大鼠脊髓小胶质细胞被激活,米诺环素处理可促使小胶质细胞向M2表型转化并促进髓鞘再生。     

Hepatocyte growth factor-modified adipose tissue-derived stem cells improve erectile function in streptozotocin-induced diabetic rats

Abstract

TGFβ1-Smad signaling pathway is closely related to various tissues fibrosis. Hepatocyte growth factor (HGF) has been shown to antagonize TGFβ1-Smad signaling and may improve kidney tissue fibrosis in diabetic models. Penile fibrosis is a pathological condition which occurs during diabetic erectile dysfunction (ED). The aim of this study was to examine the effect of the treatment of ED in diabetic rats with a combination of HGF and adipose tissue-derived stem cells (ADSC). In this diabetes model, rats were injected intraperitoneally with 60?mg streptozotocin (STZ) to induce diabetes. Three months later, the diabetic rats were divided into a negative control(NC) group, an ADSC-treated group and an ADSC?+?HGF-treated group while normal rats were assigned into a sham group. Rats in the sham and NC groups were injected in the corpus cavernosum with phosphate-buffered saline, while rats in the other groups were injected with either ADSC or ADSC?+?HGF. One month later, erectile function was examined in each group and penile tissues were collected for experiments. The expression of smooth muscle actin (SMA) and platelet-endothelial cell adhesion molecule-1 (PECAM-1) was analyzed by Western blotting. The smooth muscle and collagen deposition in corpus cavernosum was evaluated by Masson staining, while endothelial changes were assessed immunohistochemically. Cell apoptosis was detected by the TdT-mediated dUTP nick-end labeling (TUNEL) assay. The results revealed that ADSC alone can significantly improve erectile function in diabetic rats, but in combination with HGF the improvement was more prominent, showing higher content of smooth muscle and endothelial cells and lower cell apoptotic index in corpus cavernosum. Treatment with HGF can significantly enhance the beneficial effect of ADSC on erectile function in diabetic rats, and this effect might be closely related to the down-regulation of TGFβ1-Smad signaling.     

Effect of stressful stimulation on the incidence of streptozotocin-induced diabetes in mice

In three experiments, groups of 8-18, 45-day-old male CD-1 mice were injected with a single dose of streptozotocin (STZ) and were followed for 12-31 weeks. Experimental groups were given periodic. light-shock stimulation beginning at various times after streptozotocin injection. Blood samples were taken biweekly from all mice. Blood glucose levels were attenuated over a 22 week period in mice that were stimulated during the first 72 hours after STZ injection. Incidence of insulin-dependent diabetes (blood glucose levels over 150 mg%) was also significantly reduced in stimulated mice. Progressively increasing correlations between sampling order and blood glucose levels, which were significant over the last 12 weeks of one experiment, indicated that blood glucose levels of caged, diabetic mice responded markedly to laboratory procedures.