Identifying the stability of housekeeping genes to be used for the quantitative real-time PCR normalization in retinal tissue of streptozotocin-induced diabetic rats

AIM:To investigate the stability of the seven housekeeping genes:beta-actin(ActB),glyceraldehyde-3-phosphate dehydrogenase(GAPDH),18s ribosomal unit 5(18s),cyclophilin A(CycA),hypoxanthine-guanine phosphoribosyl transferase(HPRT),ribosomal protein large P0(36B4)and terminal uridylyl transferase 1(U6)in the diabetic retinal tissue of rat model.METHODS:The expression of these seven genes in rat retinal tissues was determined using real-time quantitative reverse transcription polymerase chain reaction(RT-qPCR)in two groups;normal control rats and streptozotocininduced diabetic rats.The stability analysis of gene expression was investigated using geNorm,NormFinder,BestKeeper,and comparative delta-Ct(ΔCt)algorithms.RESULTS:The 36B4 gene was stably expressed in the retinal tissues of normal control animals;however,it was less stable in diabetic retinas.The 18s gene was expressed consistently in both normal control and diabetic rats’retinal tissue.That this gene was the best reference for data normalisation in RT-qPCR studies that used the retinal tissue of streptozotocin-induced diabetic rats.Furthermore,there was no ideal gene stably expressed for use in all experimental settings.CONCLUSION:Identifying relevant genes is a need for achieving RT-qPCR validity and reliability and must be appropriately achieved based on a specific experimental setting.

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.

N-acetylcysteine attenuates ischemia/reperfusion-induced cardiocyte apoptosis in diabetic rats

Objective：To study the effects of N-acetylcysteine （NAC） on ischemia/ reperfusion （I/R）-induced myocyte apoptosis in diabetic rats. Methods：The I/R heart model was made by ligation of the left anterior descending coronary artery （LAD） close to its origin. The LAD was occluded for 30 min followed by removal of ligation to allow subsequent reperfusion for 3 h. 72 rats were randomly divided into two groups , non-diabetic group （C, n = 36） and diabetic group ,（D, n = 36）. The animals in C group were randomly reassigned into sham-operated group （CS, n = 12） , I/R group （C I/R, n = 12） and treated with NAC group （CN, n = 12）. The rats in D group were also reassigned to sham-operated group （DS, n = 12） , I/R group （DI/R, n = 12） and treated with NAC group （DN, n = 12）. Malondialdehyde （MDA） and creatine kinase isoenzyme-MB （CK-MB） were measured. Infarct size（IS/AAR%）, the apoptosis index（AI） by TUNEL staining, the number of the cells positive for Caspase-3 and positive expression index （PEI） were calculated. Results：After I/R, the IS/AAR%, CK-MB, MDA, AI and Caspase-3 PEI were higher in diabetic group than those in non-diabetic group. Treatment with NAC decreased the above parameters in both non-diabetic and diabetic rats, but the parameters in diabetic rats were higher than those in non-diabetic rats. Conclusion：Diabetic rat hearts are more susceptible to I/R-induced myocardial necrosis and myocyte apoptosis. NAC can decrease the infarct size and attenuate cardiomyocyte apoptosis in both non-diabetic and diabetic rats, but the therapeutic effects are less effective in diabetic rats than those in non-diabetic rats.

Effect of Bu-Zhong-Yi-Qi-Tang on deficiency of N-glycan/nitric oxide and islet damage induced by streptozotocin in diabetic rats

AIM: To investigate the effect of Bu-Zhong-Yi-Qi-Tang (Decoction for Reinforcing Middle Jiao and Replenishing Qi) on deficiency of N-glycan/nitric oxide (NO) and islet damage induced by injecting two medium doses of streptozotocin (STZ). METHODS: Diabetes was induced by intraperitoneal injection of STZ at 55 mg/kg on day 1 and day 8. Islet damage was evaluated using a scoring system. Nitrite, nitrate, α-mannosidase and amylase activities were measured by colorimetry. N-glycan patterns of amylase were determined with lectin [ConA, pisum sativum agglutinin (PSA), peanut agglutinin (PNA), and lens culinaris agglutinin (LCA)] affinity precipitation method. RESULTS: Severe islet necrosis and mild islet atrophy were observed in diabetic rats. The number and size ofislets, the activities of α-mannosidase, amylase and nitrite were decreased, while the binding of PNA and LCA to amylase was increased. All of which were improved after treatment with Bu-Zhong-Yi-Qi-Tang. Islet damage was significantly correlated with nitrite, nitrate, α-mannosidase, amylase and the binding of LCA, PNA, and PSA to amylase.CONCLUSION: STZ-induced islet damage is related to N-glycan deficiency in proteins by blocking α-mannosidase activity and no deficiency, accumulation of unfolded proteins, and endoplasmic reticulum stress and activation of cellular signals, all of which are improved after treatment with Bu-Zhong-YiQi-Tang.

Changes in 5α-reductase (type 2) gene expression in epididymis of puberty diabetic rats

The changes in 5α-reductase (type 2 ) gene expression in the epi-didymis of puberty diabetic rats were studied by the Northern blot and Dotblot method. Rats were divided into 3 groups: the control group (C), thediabetic group (D), and the diabetic group with insulin treatment (DI).Results: The Northern blot intensity of the caput epididymis in Group D is

Phenotypic Modulation of Mesangial Cells in Diabetic Rats and Effect of Tujian Mixture (菟箭合剂) on It

Objective: To explore whether there is phenotypic modulation of mesangial cells in streptozotocin (STZ) induced diabetic rats and study the effect of Tujian Mixture (TJM) on it. Methods: SD rats were divided into the normal control group , the unilateral nephrectomized control group , the STZ induced diabetes mellitus with unilateral nephrectomy model group , the Valsartan treated group (VT group, n=8) and the TJM treated group , rats in the latter two groups were modeled as in the DM group and treated with Valsartan (20 mg/kg·d) and TJM (20g/kg·d) respectively for 12 weeks. The expression of α-smooth muscle actin (α-SMA) and transforming growth factor-β 1 (TGF-β 1) in rats’ glomeruli were observed by immunohistochemistry assay, and the ratio of α-SMA and TGF-β 1 positive area/total glomerule tuft area (SMA/GT and TGF/GT) were analyzed using computer-assisted image analysis software. Results: In the NC and the QC groups, only trace of α-SMA positive staining was found. But there was prominant α-SMA positive staining in glomeruli of the DM group, with SMA/GT and TGF/GT increased significantly , and marked increase of 24 hrs proteinuria excretion ( P<0 01). As compared with the DM group, the three indexes were all significantly lower in the VT and ZY groups , and the lowering of proteinuria was more significant in the ZY group than that in the VT group (P<0 01). Conclusion: The expression of α-SMA in glomeruli in STZ induced diabetic rats with unilateral nephrectomy is pronounced, indicating that phenotypic modulation of mesangial cells involvement in the pathogenesis of diabetic nephropathy. TJM and Valsartan can reduce 24 hrs proteinuria excretion, inhibit the phenotypic modulation of mesangial cells and the expression of TGF-β 1 in glomeruli of diabetic rats, and the effect of TJM is more potent than that of Valsartan in lowering urinary protein excretion..

1,25-Dihydroxyvitamin D_(3) effects on the regulation of the insulin receptor gene in the hind limb muscle and heart of streptozotocin-induced diabetic rats

In the present study, we examine the effects of the treatment with 1,25-dihydroxyvitamin D3 [150 IU/Kg (3.75 μg/Kg) once a day, for 15 days] to non-diabetic and streptozotocin-induced diabetic rats. The results indicate that treatment with 1,25-dihydroxyvitamin D3 had minor effects in non-diabetic rats. The same treatment in streptozotocin-induced diabetic rats, although it did not correct the hyperglycemia and hypoinsulinemia induced by the diabetes, caused other actions that could mean beneficial effects on the amelioration of diabetes e.g., it avoided body weight loss, increased calcium and phosphorus plasma levels, and corrected the over-expression of the insulin receptor mRNA species of 9.5 and 7.5 Kb present in the hind limb muscle and heart of these animals. These genomic 1,25-dihydroxyvitamin D3 effects could involve transcriptional mechanisms of repression mediated by vitamin D response elements in the rat insulin receptor gene promoter. Using computer analysis of this promoter, we propose the -249/-235 bp VDRE (5’GGGTGACCCGGGGTT3’) with a pyrimidine (T) in the (+7) position of the3’half-site as the best candidate for negative control by 1,25-dihydroxy-vitamin D3. In addition, posttranscriptional mechanisms of regulation could also be implicated. Thus, computer inspection of the5’untranslated region of the rat insulin receptor pre-mRNA indicated the presence of a virtual internal ribosome entry segment whereas the computer inspection of the3’untranslated region localized various destabilizing sequences, including various AU-rich elements. We propose that through these virtual cis-regulatory sequences, 1,25-dihydroxyvitamin D3 could control the translation and stability of insulin receptor mRNA species in the hind limb muscle and heart of diabetic rats.

Effect of Tangweian Jianji on upper gastrointestinal remodeling in streptozotocin-induced diabetic rats

AIM： To investigate the effect of Tangweian Jianji （TWAJJ） on the biomechanical and morphometrical remodeling of the upper gastrointestinal tract in diabetic rats. METHODS： Diabetes was induced in 27 rats by in- jecting streptozotocin （40 mg/kg body weight）, the animals were then divided into three groups （n = 9 in each group）, i.e., diabetic control （DM）; high dose （10 g/kg, T1） and low dose （5 g/kg, T2）. Another 10 rats acted as normal controls （Control）. TWAJJ was admin- istered by gavage once daily. Blood glucose and serum insulin levels were measured. Circumferential length, wall thickness and opening angle were measured from esophageal, duodenal, jejunal and ileal ring segments. The residual strain was calculated from the morpho- metric data. Step-wise distension was carried out on esophageal and jejunal segments. The obtained data on the length, diameter and pressure changes were then used to calculate the circumferential and longitu- dinal stresses and strains. Real-time reverse transcrip- tion polymerase chain reaction was used to detect the receptor of advanced glycation end-products （RAGE） mRNA level in jejunal tissues. RESULTS： At the end of the experiment, the blood glucose level was significantly higher and the serum insulin level was significantly lower in DM, T1 and T2 groups than in the control group （Glucose： 30.23 ± 0.41 mmol/L, 27.48 ± 0.27 mmol/L and 27.84 ± 0.29 mmol/ L vs 5.05 ± 0.04 mmol/L, P = 1.65 x 10-16, P = 5.89 x 1019 and P = 1.63 x 10-Is, respectively; Insulin： 1.47 ± 0.32 °tg/L, 2.66 ± 0.44 pg/L, 2.03 ± 0.29 pg/L and 4.17 ± 0.54 pg/L, P = 0.0001, P = 0.029 and P = 0.025, re- spectively）. However, these levels did not differ among the DM, T1 and T2 groups. The wet weight per unit length, wall thickness and opening angle of esophageal and intestinal segments in the DM group were signifi- cantly higher than those in the control group （from P = 0.009 to P = 0.004）. These parameters in the T1 group were significantly lower than those in the DM group （wet weight, duodenum： 0.147 ± 0.003 g/cm vs 0.158 ± 0.001 g/cm, P = 0.047; jejunum, 0.127 ± 0.003 g/cm vs 0.151：1：0.002 g/cm, P = 0.017; ileum, 0.127 ± 0.004 g/cm vs 0.139 ± 0.003 g/cm, P = 0.046; wall thickness, esophagus： 0.84±0.03 mm vs 0.94 ± 0.02 ram, P = 0.014; duodenum： 1.27 ± 0.06 mm vs 1.39 ± 0.05 ram, P = 0.031; jejunum： 1.19 ± 0.07 mm vs 1.34 ± 0.04 mm, P = 0.047; ileum： 1.09 ± 0.04 mm vs 1.15 ± 0.03 mm, P = 0.049; opening angle, esophagus： 112.2 ± 13.2° vs 134.7 ± 14.7°, P = 0.027; duodenum： 105.9 ± 12.3° vs 123.1 ± 13.1°, P = 0.046; jejunum： 90.1 ± 15.4° vs 115.5 ± 13.3°, P = 0.044; ileum： 112.9 ± 13.4° vs 136.1 ± 17.1°, P = 0.035）. In the esophageal and jejunal segments, the inner residual stain was significantly smaller and the outer residual strain was larger in the DN group than in the control group （P = 0.022 and P = 0.035）. T1 treatment significantly restored this biomechanical alteration （P = 0.011 and P = 0.019）, but T2 treatment did not. Fur- thermore, the circumferential and longitudinal stiffness of the esophageal and jejunal wall increased in the DM group compared with those in the control group. T1, but not T2 treatment, significantly decreased the cir- cumferential wall stiffness in the jejunal segment （P = 0.012） and longitudinal wall stiffness in the esophageal segment （P = 0.023）. The mRNA level of RAGE was significantly decreased in the T1 group compared to that in the DN group （P = 0.0069）. CONCLUSION： TWAJJ （high dose） treatment partly restored the morphometric and biomechanical remodel- ing of the upper gastrointestinal tract in diabetic rats.

Effect of angiotensin Ⅱ type 1 receptor blocker and angiotensin converting enzyme inhibitor on the intraocular growth factors and their receptors in streptozotocin-induced diabetic rats

AIM： To investigate the effect of angiotensin II type 1 receptor blocker （ARB） and angiotensin converting enzyme inhibitor （ACEI） on intraocular growth factors and their receptors in streptozotocin-induced diabetic rats. METHODS： Forty Sprague-Dawley rats were divided into 4 groups： control, diabetes mellitus （DM）, candesartan- treated DM, and enalapril-treated DM （each group, n---10）. After the induction of DM by streptozotocin, candesartan [ARB, 5 mg/（kg · d）] and enalapril [ACEI, 10 mg/（kg · d）] were administered to rats orally for 4Wko Vascular endothelial growth factor （VEGF） and angiotensin II （Ang II） concentrations in the vitreous were measured using enzyme-linked immunosorbent assays, and VEGF receptor 2 and angiotensin II type 1 receptor （ATIR） levels were assessed at week 4 by Western blotting. RESULTS： Vitreous Ang II levels were significantly higher in the DM group and candesartan-treated DM group than in the control （P=0.04 and 0.005, respectively）. Vitreous ATIR increased significantly in DM compared to the other three groups （P〈0.007）. Candesartan-treated DM rats showed higher vitreal ATIR concentration than the enalapril-treated DM group and control （P〈0.001 and P=0.005, respectively）. No difference in vitreous Ang II and ATIR concentration was found between the enalapril- treated DM group and control. VEGF and its receptor were below the minimum detection limit in all 4 groups. CONCLUSION： Increased Ang II and ATIR in the hyperglycemic state indicate activated the intraocular renin-angiotensin system, which is inhibited more effectively by systemic ACEI than systemic ARB.

Histopathological changes in retinas and F-ERG features of streptozotocin-induced diabetic rats treated with ozone

AIM： To study the histopathological changes in the retina and flash electroretinogram （F-ERG） features of ozone-treated streptozotocin （STZ）-induced diabetic rats. METHODS： Seventy male Sprague Dawley rats were grouped as follows： blank group （GB, n=10）, model control group （GM, n=18）, ozone group （GOs, n=19）, and oxygen group （GO2, n=18）. The model was induced by single intraperitoneal injection of STZ. Ozone or oxygen enteroclysm was given twice per week for 4wk. F-ERG and histopathological examinations were performed one month after treatment. RESULTS： Under dark adaption, as compared to GB, the other groups each had differential decreases in the a-wave amplitudes （P〈0.05）; the latencies were delayed in GM, GO2, and GO3 rats （P〈0.05）. Similar results were observed under light adaption, with the exception that the a-wave of the amplitudes （F=0.28, P〉0.05）. There were significant differences in the apoptosis index among the groups （P〈0.05）. Under ozone treatment, apoptosis was decreased in GO3 as compared to GM and GO2 . CONCLUSION： Ozone administration alleviates nerve damage and reduces pathology and apoptosis in the retinas of diabetic rats.

Prophylactic Pattern Scanning Laser Retinal Photocoagulation for Diabetic Retinopathy in Spontaneously Diabetic Torii Fatty Rats: Preliminary Experimental Results

Research Background and Purpose: The number of diabetic patients is rapidly increasing, making it crucial to find methods to prevent diabetic retinopathy (DR), a leading cause of blindness. We investigated the effects of prophylactic pattern scanning laser retinal photocoagulation on DR development in Spontaneously Diabetic Torii (SDT) fatty rats as a new prevention approach. Methods: Photocoagulation was applied to the right eyes of 8-week-old Spontaneously Diabetic Torii (SDT) fatty rats, with the left eyes serving as untreated controls. Electroretinography at 9 and 39 weeks of age and pathological examinations, including immunohistochemistry for vascular endothelial growth factor and glial fibrillary acidic protein at 24 and 40 weeks of age, were performed on both eyes. Results: There were no significant differences in amplitude and prolongation of the OP waves between the right and left eyes in SDT fatty rats at 39 weeks of age. Similarly, no significant differences in pathology and immunohistochemistry were observed between the right and left eyes in SDT fatty rats at 24 and 40 weeks of age. Conclusion: Prophylactic pattern scanning retinal laser photocoagulation did not affect the development of diabetic retinopathy in SDT fatty rats.

Comparative Study on Effects of Different Treatments in Preventing Myocardial Ischemia Caused by Coronary Artery Ligation in Diabetic Rats

Objective: To compare the preventive effect of treatment with different methods of traditional Chinese medicine(TCM) for myocardial ischemia caused by coronary artery ligation in diabetic rats. Methods: Animal models established by streptozotocin plus coronary artery ligation were treated by modified Taoren Chengqi Deconcton (MTRCQD) and different combinations of its imgreddints respectively , and the dffects on is chemia area , occurrence of arrhbthmia.T-wave in ECG and 2 hrs post-operational survival rate were observed and compared . Results :MTRCQD and differdnt combinations of its ingredients could reduce the area of is chemia and elevate survival rate significantly (P<0.05-0.01), especiclly in the group treated with MTRCQD plus leech .Conclusion:TCM treatment of invigorating QI nourshing Yin ,purging Heat and activating blood circulation is an deeective treatment for diabetic coronaty heart disease.

Antidiabetic and Anti-oxidative Effects of Honokiol on Diabetic Rats Induced by High-fat Diet and Streptozotocin

Objective To study the antidiabetic and anti-oxidative effects of honokiol （Hon） in Magnolia officinalis and its underlying molecular mechanism in diabetic rats induced by high-fat diet （HFD） and streptozotocin （STZ）. Methods After ig administration with Hon [25, 50, and 100 mg/（kg.d）] to diabetic rats for consecutive 10 weeks, the levels of blood glucose （BG）, oral glucose tolerance （OGT）, blood lipids including total cholesterol （TC）, triglyceride （TG）, high density lipoprotein-cholesterol （HDL-C）, and low density lipoprotein-cholesterol （LDL-C）, hepatic oxidative stress including the activities of superoxide dismutase （SOD）, catalase （CAT）, glutathione peroxidase （GSH-Px）, methane dicarboxylic aldehyde （MDA）, and cytochrome P4502E1 （CYP2E1） in diabetic rats were measured. Results Compared to the diabetic control rats, ig administration of Hon resulted in significant decrease in BC, TC, TG, and LDL-C levels in serum, as well as hepatic CYP2E] activity and MDA content in diabetic rats, whereas the level of OGT and activities of hepatic CAT, SOD, and CSH-Px in diabetic rats were significantly increased. Conclusion Hon could alleviate hyperglycemia, hyperlipemia, hepatic oxidative damage, and insulin resistance in diabetic rats by inhibiting hepatic CYP2E1 activity.

Extracts of passion fruit peel and seed of Passiflora edulis(Passifloraceae) attenuate oxidative stress in diabetic rats

This study was aimed at evaluating the anti-diabetic potential of passion fruit Passiflora edulis(EPE) extracts in diabetic rats, following Streptozotocin(STZ) induced oxidative stress. Thirty adult Wistar rats were divided into five groups, with six rats in each group. The control rats were injected intraperitoneally with citrate buffer(pH 4.5). The remaining groups of rats were administered single dose of 45 mg·kg-1 of STZ by intraperitoneal route to induce diabetes. The diabetic animals were treated with 250 and 500 mg·kg-1 of EPE and glibenclamide 0.6 mg·kg-1 for fifteen days by oral route. Blood glucose, end organ oxidative stress marker, and anti-oxidants were assayed. Further, histopathological investigation of pancreas was studied at the end of the experimentation. The results revealed that subacute administration of EPE significantly(P < 0.001) controlled the blood glucose level in the diabetic rats. In addition, EPE extract protected the end organs by restoring the anti-oxidants enzyme, significantly increasing super oxide dismutase level(SOD) and decreasing catalase(CAT) and TBARS level in visceral organs. In conclusion, that EPE extracts showed anti-diabetic and anti-oxidant potential against streptozotocin-induced diabetes.

Protective effect of LIF-huM SCs on the retina of diabetic model rats

AIM:To investigate the protective effect of human umbilical cord mesenchymal stem cells(hUCMSCs)modified by the LIF gene on the retinal function of diabetic model rats and preliminarily explore the possible mechanism.METHODS:A stably transfected cell line of hUCMSCs overexpressing leukemia inhibitory factor(LIF)was constructed.Overexpression was verified by fluorescent quantitative polymerase chain reaction(qPCR).Forty-eight adult Sprague-Dawley rats were randomly divided into a normal control group(group A),streptozotocin-induced diabetic control group(group B),diabetic rats at 3mo injected with empty vector-transfected hUCMSCs(group C)or injected with LIF-hUCMSCs(group D).Four weeks after the intravitreal injection,analyses in all groups included retinal function using flash electroretinogram(F-ERG),retinal blood vessel examination of retinal flat mounts perfused with fluorescein isothiocyanate-dextran(FITCdextran),and retinal structure examination of sections using hematoxylin and eosin staining.Expression levels of adiponectin(APN),high-sensitivity C-reactive protein(hsCRP),and neurotrophin-4(NT-4)in each group was detected using immunohistochemistry,PCR,Western blotting,and ELISA,respectively.RESULTS:A stable transgenic cell line of LIF-hUCMSCs was constructed.F-ERG and FITC-dextran examinations revealed no abnormalities of retinal structure and function in group A,severe damage of the retinal blood vessels and function in group B,and improved retinal structure and function in group C and especially group D.qPCR,ELISA,and Western blot analyses revealed progressively higher APN and NT-4 expression levels in groups B,C,and D than in group A.hs-CRP expression was significantly higher in group B than in groups A,C,and D,and was significantly higher in group C than in group D(P<0.05).CONCLUSION:LIF-hUCMSCs protect the retina of diabetic rats by upregulating APN and NT-4 expression and downregulating hs-CRP expression in the retina.

Effects of Shuang Dan Ming Mu Capsule on Expression of VEGF-a, VEGF-b, VEGF-c and the VEGF receptor, Flk-1, in Diabetic Retinopathy Rats

Objective The effects of Shuang Dan Ming Mu capsule on expression of VEGF-a,VEGF-b,VEGF-c and the VEGF receptor,Flk-1,were examined in a diabetic retinopathy rats model.Methods Forty Sprague-Dawley(SD)rats were randomized into Groups A(blank),B(model),C(Shuang Dan Ming Mu)and D(positive control)group,with each group containing10rats and20eyes.Rats from groups B,C and D were administered one dose of50mg/kg streptozotocin(STZ)by tail vein injection to establish a diabetic rat model.One week after model preparation,medication was continuously administered by gavage.After gavage for8weeks,the animals were sacrificed and retinal expression of VEGF-a,VEGF-b,VEGF-c and Flk-1was quantified by immunohistochemical analysis.Results At week8of drug administration after model preparation,the average protein expression grayscale values for VEGF-a,VEGF-b,VEGF-c and Flk-1in the rats model,Shuang Dan Ming Mu and positive control groups were all lower than those in the normal group,while the mean optical density values were higher than those in the normal group.When the model group was compared to the normal group,the difference was extremely significant(P<0.01).The mean grayscale values of VEGF-a,VEGF-b,VEGF-c and Flk-1in the Shuang Dan Ming Mu and positive control groups were all higher than those in the model group,while the mean optical density values were lower than those in the model group(P<0.05or0.01).Conclusion Shuang Dan Ming Mu capsule can significantly decrease the expression of VEGF-a,VEGF-b,VEGF-c and Flk-1in the retinas of diabetic model rats and exhibit some protective effects in their retinas.

Effect of electroacupuncture on conduction velocity of the sciatic nerve in experimental diabetic rats and its mechanisms

Objective To investigate the mechanisms of acupuncture in accelerating regeneration of injured sciatic nerve, the effect of electroacupuncture （EA） at ＂Huantiao （环跳 GB 30）＂ and ＂Zusanli （足三里 ST 36）＂ on conduction velocity and mRNA expression of receptors of advanced glycation end products （RAGE） of the sciatic nerve were observed in experimental diabetic rats. Methods Streptozotocin was injected into the left abdomen in 30 male rats to establish diabetes mellitus （DM） models with hyperglycemia （〉16.7 mmol/L）. Thirty rats with DM were divided into a diabetes model group （group DM）, a Methycobal group （group MET） and an EA group （group EA）. Another 8 rats comparable in body weight and age were used as a normal control group （group NC）. General situation and blood sugar levels of all the rats were recorded, and the conduction velocities of the sciatic nerves were measured. RAGE mRNA expression of the sciatic nerve was detected by means of reverse transcription polymerase chain reaction（RT-PCR）16 weeks after treatment. Results After 16 weeks, the conduction velocities of the sciatic nerves were lowered in group DM, compared with those in group NC, indicating lesion of peripheral nerves. Compared with group DM, the conduction velocities of the sciatic nerves were significantly elevated in both group EA and group MET （P〈0.01 ）, and there was a significant difference between the two groups, showing superiority of EA to Methycobal （P〈0.01）. The RAGE mRNA levels of the sciatic nerves in group DM were significantly higher than those in group NC （P〈0.01）. The RAGE mRNA levels of the sciatic nerves in both group EA and group MET were remarkably lowered than those in group DM （P〈0.01）, and the decrease in group EA was more obviously than that in group MET （P〈0.01）. Conclusion EA may exert its therapeutic effects on diabetic perineuropathy （DPN） by way of regulating abnormal expression of RAGE mRNA in the sciatic nerve and alleviating its injury caused by advanced glycation end products （AGEs） accumulation and diminishing oxidative stress to enhance its conduction velocity.

Modulation of fasting blood glucose by raw banana powder in alloxan-induced diabetic rats

This study aimed to observe the influence of raw banana powder(RBP)on fasting blood glucose(FBG),blood lipid and other biochemical indicators in type-2 diabetic rats and therefore to provide experimental evidences for developing suitable food from banana powder for diabetic patients.Eight Sprague-Dawley rats were selected randomly as the normal control group(NCG)before the experiment.After establishing type-2 diabetic rat models(11.1-16.7 mmoL/L)by alloxan,32 rats were divided into four groups:the diabetic control group(DCG,n=8),low-dose group(LDG,n=8),middle-dose group(MDG,n=8)and high-dose group(HDG,n=8).The LDG,MDG and HDG rats received gastric perfusion of RBP at the doses of 2 g/kg,4 g/kg and 6 g/kg per day,respectively.After four weeks,oral glucose tolerance test was carried out in each group,and then the FBG level,blood lipid,insulin,short chain fatty acids content,pH value of colon content and other biochemical indicators of rats in each group were determined and compared among the groups.Results showed that the levels of FBG significantly decreased in the LDG(11.97±0.83),MDG(8.95±0.45)and HDG(9.28±1.45),compared with their initial values(13.00±1.25,13.68±0.75 and 13.91±0.80,respectively).The FBG levels in these three groups were obviously lower than that in the DCG.However,there were no dramatic FBG changes in the NCG and DCG(5.77±0.59,14.14±0.72)compared with the initial stage(5.55±0.23,13.93±0.47).The RBP intervention increased insulin-sensitivity index and regulated postprandial blood glucose.Besides,RBP showed the positive effects on symptoms of type 2 diabetic rats,such as the reduction of weight gain and total cholesterol.

Biomechanics of Bone in Experimental Diabetic rats.

The biomechanics of bone In diabetics and its response to insulin treatment was not clear.We investigated the impace of alloxan-induced diabetes and insulin treatment on the biomechanical characteristics of bones．Sprague-Dawley rats were divided into three groups: