Animals ; Diabetes Mellitus, Experimental/drug therapy* ; Fibrosis/prevention & control* ; Hyperglycemia/prevention & control* ; Hypoglycemic Agents/pharmacology* ; Inflammation/prevention & control* ; Male ; Rats ; Rats, Sprague-Dawley ; Stilbenes/pharmacology*

OBJECTIVEUse laser confocal microscopy overspeed camera technique and fluorescence albumin labeling to study the acting mechanism of Qishen Yiqi Drop Pill (QYDP) for intervening irido-microangiopathy (IMAP) in diabetic rats.

METHODSRat model of diabetes mellitus type 1 (DM1) was established by intraperitoneal injection of streptozocin (STZ). The model rats were randomly divided into three groups, the treatment group, the model group and the control group. At the same time a normal control group was set up. The treatment group was medicated with QYDP (prepared into liquid form), and the control group with Duobeisi liquor (1 g/kg per day) for 10 months. The dynamic state of iris microcirculation in rats was observed using laser confocal microscopy overspeed camera.

RESULTSCompared with the treatment group, blood flow in iris of model rats was slower significantly (P < 0.01); the fluorescence density and leakage area of inside and outside iris vessels, and the iris vascular diameter were significantly higher in the model group than those in the treatment group (P < 0.01).

CONCLUSIONQYDP has definite effect in improving iris microcirculation, which can accelerate the blood flow, inhibit the abnormal expansion of vessels and improve the increased iris micro-vascular permeability.

Animals ; Capillary Permeability ; drug effects ; Diabetes Mellitus, Experimental ; complications ; drug therapy ; Diabetes Mellitus, Type 1 ; complications ; drug therapy ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Iris ; blood supply ; Iris Diseases ; etiology ; prevention & control ; Male ; Phytotherapy ; Rats ; Rats, Sprague-Dawley

OBJECTIVEAs an endogenous antioxidant, taurine could retard the development of diabetic cardiovascular complications. Whereas, whether TAU has a protective effect on diabetic vascular endothelium in young patients is still unclear. This study aimed to investigate the protective effect of taurine on early vascular endothelial dysfunction and its possible mechanism by detecting the changes of oxLDL/LOX-1 system in young STZ-induced diabetic rats. Doing so, the authors expect to find an effective approach in clinical practice to the prevention and treatment of diabetic vascular complication.

METHODSix-week-old rats were divided randomly into normal control (CN group, n=8), diabetes mellitus group (DM group, n=8) and taurine supplement group (DM+TAU group, n=8). Diabetes was induced in the rats by intraperitoneal injection of streptozotocin (STZ, 60 mg/kg) and after the onset of diabetes, the rats in DM+TAU group were given free access to drinking water containing 1% taurine. At the end of 4 weeks, blood glucose, serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) and high-density lipoprotein (HDL), oxidized low density lipoprotein (oxLDL) and sICAM-1 levels were determined, meanwhile LOX-1 and ICAM-1 expression on abdominal aortas were examined by immunostaining, Western blotting and reverse transcription PCR, respectively. The results were quantified by densitometry.

RESULTCompared to normal control, in STZ-induced diabetic rats, the levels of serum TC, TG, LDL, oxLDL and sICAM-1 were all increased (P<0.01 for all), meanwhile LOX-1 and ICAM-1 expression (protein and mRNA) in the endothelium layers of abdominal aortas were also markedly enhanced (P<0.01 for all); while in taurine supplemented rats, the levels of serum TG (0.64+/-0.12 vs. 0.97+/-0.18), TC (0.82+/-0.18 vs. 1.01+/-0.23), oxLDL (3.1+/-0.6 vs. 4.2+/-0.6), sICAM-1 (108.3+/-18.0 vs. 130.7+/-17.4), expression of LOX-1 and ICAM-1 protein (1.02+/-0.19 vs. 2.60+/-0.33, 1.21+/-0.22 vs. 2.98+/-0.31) as well as mRNA (0.45+/-0.09 vs. 0.96+/-0.15, 0.50+/-0.07 vs. 0.87+/-0.16) were all markedly lower than those of untreated diabetic rats (P<0.05 for all). Also, the level of LOX-1 protein expression was positively correlated with levels of serum oxLDL (r=0.922, P=0.001), sICAM-1 (r=0.753, P=0.031) and ICAM-1 expression on abdominal aorta (r=0.849, P=0.008).

CONCLUSIONVascular endothelial dysfunction was present in early stage of young diabetic rats and taurine supplement could protect against this early endothelial dysfunction by its antioxidation to inhibit the role of oxLDL/LOX-1 system in young rats with diabetes mellitus.

Animals ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; Diabetic Angiopathies ; prevention & control ; Endothelium, Vascular ; metabolism ; Male ; Oxidative Stress ; Rats ; Rats, Wistar ; Taurine ; therapeutic use

OBJECTIVES: This study examined the effect of cilostazol, a potent phosphodiesterase inhibitor, on the progression of neuropathies associated with streptozotocin-induced diabetes mellitus in Sprague-Dawley rats. METHODS: Eight weeks after streptozotocin treatment, a pelleted diet containing 0.03% cilostazol (15 mg/kg body weight) was given for four weeks. Body weight, blood glucose level, motor nerve conduction velocity (MNCV), myelinated fiber density and size distribution of sciatic nerves were compared between age-matched normal rats (Group 1), control diabetic rats (Group 2) and cilostazol-treated diabetic rats (Group 3). RESULTS: Body weight was significantly reduced and blood glucose level was significantly increased in diabetic rats (Group 2 and 3) compared to normal rats. MNCV and cAMP content of sciatic nerves were significantly reduced in diabetic rats 12 weeks after streptozotocin treatment. Myelinated fiber size and density were also significantly reduced, and thickening of the capillary walls and duplication of the basement membranes of the endoneural vessels were observed in the diabetic rats. Whereas both body weight and blood glucose level of Group 3 did not differ significantly from those of Group 2, cilostazol treatment significantly increased MNCV and cAMP content of sciatic nerves in Group 3 but not to the levels observed in Group 1. MNCV positively correlated with cAMP content of sciatic nerves (r = 0.86; p < 0.001). Cilostazol treatment not only restored myelinated fiber density and size distribution but reversed some of the vascular abnormalities. CONCLUSION: These findings suggest that a reduced cAMP content in motor nerves may be involved in the development of diabetic neuropathy, and that cilostazol may prevent the progression of diabetic neuropathy by restoring functional impairment and morphological changes of peripheral nerves.
Animal ; Cyclic AMP/metabolism ; Diabetes Mellitus, Experimental/physiopathology ; Diabetes Mellitus, Experimental/drug therapy ; Diabetic Neuropathies/prevention & control* ; Diabetic Neuropathies/physiopathology ; Diabetic Neuropathies/pathology ; Male ; Neural Conduction/drug effects ; Phosphodiesterase Inhibitors/pharmacology* ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve/physiopathology ; Sciatic Nerve/pathology ; Sciatic Nerve/drug effects ; Tetrazoles/pharmacology*

BACKGROUNDDiabetic cardiovascular complication is a major cause of mortality in type 2 diabetic patients. Hyperglycemia markedly increases the risk of cardiovascular disease. Endothelial dysfunction is common in type 2 diabetes mellitus (DM) and is an early indicator of diabetic vascular disease. Therefore, it is necessary to identify the effect of different hypoglycemic agents on vascular endothelium. The aim of the study was to examine and compare the effects of metformin and gliquidone on atherosclerotic lesions in streptozotocin-induced diabetic rats.

METHODSForty male Sprague-Dawley rats (age, 8 weeks; weight, 180-200 g) were included in this study and fed with a normal chow diet for 1 week. Rats (n = 10) served as the normal control group (NC group) were fed with a normal chow for another 2 weeks and received an injection of saline. The rest 30 rats fed with a high-fat diet for 2 weeks and injected streptozotocin were randomly assigned to three groups (n = 10 rats per group) as follow: type 2 DM group (DM group), DM + gliquidone group (GLI group) and DM + metformin group (MET group). Five weeks later, all rats were fasted overnight and taken tail blood samples for biochemical determinations. Then rats in the NC and DM groups were administrated with normal saline, while rats in the MET and GLI groups were administrated with metformin (100 mg/kg) or gliquidone (10 mg/kg), respectively. All medicines were given via intragastric administration for 8 weeks. After 16 weeks, plasma triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) were measured. The aortic arch was isolated from diabetic rats and was assessed by pathological sectioning using H&E staining.

RESULTSMetformin treatment prevented weight gain ((315.80 ± 52.16) g vs. (318.70 ± 68.48) g, P = 0.773), improved plasma TG, HDL-C and LDL-C levels (P = 0.006, 0.003, 0.001, respectively, all P < 0.05). However, gliquidone showed no significant effects on plasma TG and TC levels (P = 0.819, 0.053, respectively). LDL-C and HDL-C in the GLI group changed ((0.46 ± 0.10) mmol/L vs. (0.36 ± 0.14) mmol/L, P = 0.007; (0.99 ± 0.27) mmol/L vs. (1.11 ± 0.18) mmol/L, P = 0.049). Both metformin and gliquidone treatment lowered blood glucose levels (P = 0.001, 0.004, respectively, P < 0.05). Under light microscopy, no changes were observed in the aortic wall structure of each layer; the intima was smooth and the membrane elastic fibers were normal in the NC group. In the DM group, the aortic wall structure was unclear, the intima was thickened with irregular intima, and membrane elastic fibers collapsed. The aortic intima in the MET and GLI groups was smoother compared with the DM group, but the endothelial structure of the MET group was closer to that of the NC group.

CONCLUSIONSBoth metformin and gliquidone have anti-atherosclerotic effects. But the endothelial structure of the MET group was closer to that of the NC group. Metformin and gliquidone therapy can reduce serum level of LDL-C and increase level of HDL-C, whereas gliquidone therapy did not lose weight and decrease serum level of TG. These data may have important implications for the treatment of patients with type 2 DM.

Animals ; Aorta ; drug effects ; Diabetes Mellitus, Experimental ; drug therapy ; Diabetic Angiopathies ; prevention & control ; Hypoglycemic Agents ; therapeutic use ; Male ; Metformin ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; Sulfonylurea Compounds ; therapeutic use

OBJECTIVETo investigate the renal protective activity of Hsian-tsao Mesona procumbens Hemsl. water extracts in diabetic rats.

METHODSThirty Sprague-dawley female rats were randomly divided into three groups (n = 10 each), "control group" with intraperitoneal saline injection, "diabetic group" with 60 mg of intraperitoneal streptozotocin injection per kg of body weight and "Hsian-tsao group" with intragastric administration of Hsian-tsao extraction everyday for 4 weeks after intraperitoneal streptozotocin injection. The body weight and blood sugar were measured before and after model induction in the three groups. Thrombospondin-1 (TSP-1) expressions in the kidney were monitored by immunohistochemistry. Kidney ultrastructural changes were also analyzed by using transmission electron microscopy.

RESULTSBefore diabetic model induction, there were no significant differences among the three groups in body weight and blood sugar. Four weeks after the induction of diabetes, the differences became statistically significant. Electron microscopy also revealed disruption of the foot processes of the podocytes and other damages in diabetic group. These damages were significantly less severe in Hsian-tsao group when compared with the diabetic group. TSP-1 expressions in the kidney were significantly increased in both the diabetic group and Hsian-tsao group, but it was relatively lower in Hsian-tsao group than in diabetic group.

CONCLUSIONOur results showed that Hsian-tsao treatment in the diabetic rats effectively prevented the pathological alterations in the kidney and decreased the TSP-1 expression. It was suggested that Hsian-tsao had protective effect on the kidneys of the diabetic rats.

Animals ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; pathology ; Diabetic Nephropathies ; metabolism ; pathology ; prevention & control ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Kidney ; drug effects ; metabolism ; pathology ; ultrastructure ; Lamiaceae ; chemistry ; Rats ; Rats, Sprague-Dawley ; Thrombospondin 1 ; metabolism

OBJECTIVETo investigate the protective effect and mechanism of Shenqi Compound on diabetic angiopathy modeled rats.

METHODSTotally 18 SD rats were randomized into 3 groups, i.e., the normal control group, the diabetic mellitus (DM) group, and Shenqi Compound group, 6 in each group. The DM rat model was established by feeding high-fat diet (to induce hyperlipidemia) +intraperitoneal injection of small dose streptozotocin (STZ). Shenqi Compound was given to rats in the Shenqi Compound group at the daily dose of 2 g/kg. Equal volume of normal saline was given to rats in the model group and the normal control group by gastrogavage. All treatment was lasted for 12 weeks. Then 2-D and ultrasonic integrated backscatter technique were used to evaluate structural and functional changes of abdominal aorta in the progression of diabetic macroangiopathy. The fibrosis degree of the aorta vessel and myocardium capillaries were observed by using HE and Masson trichrome staining. The tension of the aortic vascular ring was determined. The transforming growth factor beta (TGF-beta) mRNA expression was detected by real time PCR (RT-PCR). The protein expression of TGF-beta, collagen I, collagen III, connective tissue growth factor (CTGF), and phosphorylation P38 MAPK were detected by Western blot.

RESULTSCompared with the normal control group, abdominal aortic systolic inner diameter, diastolic inner diameter, Peterson elastic modulus, stiffness index, and backscatter integral significantly increased; the rangeability of integral backscatter and the extension coefficient of cross section significantly decreased in the DM group (all P < 0.05). After 12 weeks aforesaid indices were obviously improved in the Shenqi Compound group (P < 0.05). Results of HE and Masson staining showed that the fibrosis degree of the aorta vessel and myocardium capillaries was obviously alleviated in rats of the Shenqi Compound group (P < 0.05). Results of the aortic vascular ring tension showed that acetylcholine induced vasodilatation and maximum diastolic percent were obviously elevated in the Shenqi Compound group (P < 0.05). Compared with the normal control group, the mRNA expression of TGF-beta, and the protein expression of TGF-beta, collagen I, and collagen III, and phosphorylation of P38 MAPK all significantly increased in the DM group (P < 0.05). Compared with the DM group, the mRNA expression of TGF-beta, and the protein expression of TGF-beta, collagen I, and collagen III, and phosphorylation of P38 MAPK all decreased (P < 0.05).

CONCLUSIONSShenqi Compound could effectively improve the arterial function in diabetic marcoangiopathy and microvascular dysfunction. The mechanism might be due to the down-regulating the expression of TGF-beta, and further suppressing the phosphorylation of P38 MAPK, reducing the synthesis of collagen I and collagen III, therefore, ameliorating arterial and myocardial interstitial fibrosis.

Animals ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Diabetes Mellitus, Experimental ; drug therapy ; Diabetic Angiopathies ; prevention & control ; Drugs, Chinese Herbal ; pharmacology ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Transforming Growth Factor beta1 ; metabolism ; p38 Mitogen-Activated Protein Kinases ; metabolism

OBJECTIVE: To investigate the effect of mycophenolate mofetil(MMF) on early inflammatory reaction of renal lesion in streptozotocin(STZ)-induced diabetic rats. METHODS: Thirty-six male Sprague-Dawley rats were randomly divided into 3 groups after uninephrectomy: normal control group, diabetic model group, and MMF-treated group. Six rats in each group were sacrificed at the 4th week and 14th week after STZ injection. Twenty-four hour urinary protein (24 h Upro) count was measured before death. The expressions of regulated on activation of normal T expressed and secreted (RANTES),ectodermal dysplasia (ED-1)and Col-IV protein in the renal tissue were detected by immunohistochemistry. The expression of RANTES mRNA in the renal tissue was detected by RT-PCR. RESULTS: MMF prevented the increasing of 24h Upro in diabetic rats,and the expressions of RANTES,ED-1,Col-IV protein and RANTES mRNA in the kidney of MMF-treated rats were significantly decreased. CONCLUSION MMF plays an early renal protective role in diabetic nephropathy, possibly through inhibition of early inflammatory reaction.
Animals ; Chemokine CCL5 ; biosynthesis ; genetics ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; Diabetic Nephropathies ; metabolism ; prevention & control ; Ectodysplasins ; biosynthesis ; genetics ; Inflammation ; metabolism ; Kidney ; metabolism ; Male ; Mycophenolic Acid ; analogs & derivatives ; therapeutic use ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley

BACKGROUNDDiabetic nephropathy is a major cause of renal failure in diabetes mellitus (DM). It has been known that renin-angiotensin system (RAS) blockers have a renal protective effect. This study aimed to investigate whether treatment with angiotensin II receptor blocker, olmesartan, could modify renal hemodynamic variables and vascular structural properties, then attenuate renal injury in streptozotocin (STZ)-induced DM rats.

METHODSDM was induced in male Wistar rats by intraperitoneal administration of STZ. The rats were then randomized to a DM group and an olmesartan treatment (OLM + DM) group. The normal group (non-DM) were administered only citrate buffer. At the end of the 14th week, blood glucose, kidney weight/body weight and urinary protein-to-creatinine ratio were determined. Further, the flow-pressure and pressure-glomerular filtration rate (GFR) relationships were determined for maximally vasodilated, perfused kidneys. From the relationship, 3 indices of vascular structural properties were estimated: slope of flow-pressure (minimal renal vascular resistance, reflecting overall luminal dimensions of preglomerular and postglomerular vasculature), slope of pressure-GFR (glomerular filtration capacity against pressure) and threshold pressure for beginning filtration at pressure-GFR (preglomerular to postglomerular vascular resistance ratio). Kidneys were then perfusion fixed for histological analysis. The renal histopathology was observed by light microscopy.

RESULTSThe body weight of DM rats was lower than that of non-DM rats. Blood glucose, kidney weight/body weight, urinary protein-to-creatinine ratio were significantly greater in DM rats than in non-DM rats. The parameters such as kidney weight/body weight, urinary protein-to-creatinine ratio in OLM + DM rats had dramatically decreased compared with those in DM rats. However, the treatment with olmesartan had no effect on blood glucose levels. The slope of flow-pressure relationship was greater in DM rats than that in non-DM rats (P < 0.05). But the slope of the pressure-GFR relationship was lower in DM rats than that in non-DM rats (P < 0.05) with the x-intercept of the line similar between the two groups. The slope of the flow-pressure relationship was decreased in DM rats group treated with olmesartan (P < 0.05). Moreover, olmesartan significantly increased the slope of the pressure-GFR relationship in DM rats (P < 0.05). The x-intercept of the pressure-GFR relationship reduced following olmesartan in DM rats.

CONCLUSIONSTreatment with olmesartan reduced urinary protein-to-creatinine ratio independent of blood glucose and increased average renal vessel lumen diameter in the perfused kidneys of STZ-induced DM rats, predominantly in preglomerular vessels, and then improved renal excretory capability. These findings were consistent with remodeling of the preglomerular vasculature in our hisological measurements.

Angiotensin II Type 1 Receptor Blockers ; therapeutic use ; Animals ; Blood Glucose ; drug effects ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; physiopathology ; Diabetic Nephropathies ; drug therapy ; prevention & control ; Hemodynamics ; drug effects ; Imidazoles ; Kidney ; drug effects ; metabolism ; pathology ; Male ; Organ Size ; drug effects ; Rats ; Rats, Wistar ; Tetrazoles

OBJECTIVETo study the protective effect of the Mixture of Shengmai Powder and Danshen Decoction (, abbreviated as the Mixture) in the rat model with type 2 diabetic cardiomyopathy in the rat model with type 2 diabetic cardiomyopathy, abbreviated as the Mixture) in the rat model with type 2 diabetic cardiomyopathy (DCM).

METHODSForty-two SD rats with DCM model, established by the combination of insulin resistance by a high-fat diet with the damage of pancreatic islet β cells by intraperitoneal injection of high dose streptozotocin (50 mg/kg) once, were evaluated in the damage of the myocardium by electrocardiogram at the end of 12 weeks of grouping and intervention administration; the extent of damage in the myocardial subcellular structure was observed by electron microscopy; the content of myocardial collagen in the left cardiac ventricle was quantified by Masson staining test; the myocardial cell apoptosis was determined by TUNEL; the changes in the mRNA expression levels of thrombospodin-1 (TSP-1) and tribbles homolog 3 (TRB-3) by real-time quantitative PCR, the expression levels of myocardial TSP-1, tumor growth factorβ1 (TGF-β1), TRB-3, and chymase were detected by immunohistochemistry, and the changes in the expression levels of myocardial TSP-1, active-TGF-β1 (A-TGF-β1) and latent-TGF-β1 (L-TGF-β1) protein were tested by Western blotting.

RESULTSCompared with the control group, the myocardial tissue was less damaged, and the extent of damage in the myocardial subcellular structure was less; the collagen fiber content and the cell apoptosis were reduced; the expression levels of TSP-1mRNA and TRB-3 mRNA, the expression levels of myocardial TSP-1, TGF-β1, TRB-3, and chymase, as well as the average expression levels of the myocardial TSP-1, A-TGFβ1, and L-TGF-β1 protein were decreased in the Mixture group.

CONCLUSIONThe Mixture of Shengmai Powder and Danshen Decoction could inhibit the process of myocardial fibrosis in the rat myocardium of DCM through multiple pathways and significantly delay the genesis and progress of DCM in hyperglycemic rats.

Animals ; Cytoprotection ; drug effects ; Diabetes Mellitus, Experimental ; complications ; drug therapy ; Diabetic Cardiomyopathies ; pathology ; prevention & control ; Disease Models, Animal ; Drug Combinations ; Drug Evaluation, Preclinical ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; Heart ; drug effects ; Male ; Myocardium ; cytology ; pathology ; Rats ; Rats, Sprague-Dawley ; Streptozocin