Objective To establish a Daphnia model of alloxan-induced diabetes. Methods Daphnia were exposed to three different concentrations of alloxan (3, 5, and 10 mmol/L) for 30 minutes. Blood glucose and survival rate were recorded for 72 hours after alloxan insult. Sequence analysis and phylogenetic inference for glucose transporters (GLUT) were clustered with the maximum-likelihood method. Using reverse transcription and quantitative polymerase chain reaction techniques, we investigated the transcriptional changes of GLUT at 12 hours after alloxan (5 mmol/L) exposure. Results Compared with control, 3 mmol/L, and 5 mmol/L as well as 10 mmol/L alloxan initially induced transient blood glucose decline by 15% for 2 hours and 12 hours respectively. In Daphnia with 5 and 10 mmol/L alloxan, their blood glucose was persistently raised by about 150% since after 24-hour insult. Survival rate of Daphnia exposure to alloxan with concentrations of 3, 5, and 10 mmol/L were 90%, 75%, and 25% respectively. We predicted seven GLUT genes in the Daphnia genome and successfully amplified them using real-time polymerase chain reaction. Two of seven GLUT transcripts were down-regulated in Daphnia with 5 mmol/L alloxan-induced diabetes. Conclusion Alloxan-induced diabetes model was successfully established in the Daphnia pulex, suggesting diabetes-relevant experiments can be conducted using Daphnia.
Alloxan ; Animals ; Blood Glucose ; analysis ; Daphnia ; Diabetes Mellitus, Experimental ; chemically induced ; physiopathology ; Disease Models, Animal ; Gene Expression Regulation ; Glucose Transport Proteins, Facilitative ; genetics ; metabolism ; Likelihood Functions ; Phylogeny ; Real-Time Polymerase Chain Reaction

OBJECTIVETo investigate the impact of hyperglycemia on the hydrogen sulfide (H2S) signaling pathway in rat penile tissue and its relationship with erectile function.

METHODSTwenty healthy male Sprague Dawley (SD) rats aged 8 weeks were randomly divided into groups A (4-week healthy control), B (4-week diabetes mellitus model), C (6-week healthy control) and D (6-week diabetes mellitus model). The rats in groups B and D were injected intraperitoneally with streptozotocin at 50 mg/kg to induce diabetes mellitus, while those in groups A and C with the same volume of normal saline. The animals were killed at 4 (groups A and B) and 6 weeks (groups C and D) after treatment for measurement of the maximal intracavernous pressure/mean arterial blood pressure (ICP(max)/MAP) by electrostimulation, determination of the H2S concentration in the plasma and penile tissue, and detection of the expressions of cystathionine-beta-synthetase (CBS) and cystathionine-gamma-lyase (CSE) in the penile corpus cavernosum by immunohisto- chemistry and Western blot.

RESULTSWith electrostimulation of the pelvic ganglia at 5V and 7 V, ICP(max)/MAP was significantly reduced in groups B (0.19 +/- 0.03 and 0.29 +/- 0.04) and D (0.14 +/- 0.04 and 0.25 +/- 0.04) as compared with A (0.46 +/- 0.07 and 0.68 +/- 0.09) and C (0.43 +/- 0.07 and 0.65 +/- 0.16) (P < 0.05). No statistically significant differences were found in the level of serum testosterone either between groups A and B ([469.19 +/- 126.46] ng/dl vs [359.08 +/- 60.06] ng/dl, P > 0.05) or between C and D ([470.44 +/- 209.28] ng/dl vs [297.01 +/- 96.58] ng/dl, P > 0.05). Groups B and D showed remarkable reduction in the H2S concentration (P < 0.05) and the expressions of CBS and CSE (P < 0.05) in comparison with A and C, and the CBS and CSE expressions were even more significantly decreased in D than in B (P < 0.05).

CONCLUSIONThe reduced concentration of H2S and decreased expressions of CBS and CSE in the penile corpus cavernosum of the diabetic rats suggested that the H2S signaling pathway might be involved in hyperglycemia-induced erectile dysfunction.

Animals ; Blood Pressure ; physiology ; Cystathionine gamma-Lyase ; metabolism ; Diabetes Mellitus, Experimental ; chemically induced ; metabolism ; Electric Stimulation ; methods ; Erectile Dysfunction ; etiology ; Humans ; Hydrogen Sulfide ; metabolism ; Hyperglycemia ; metabolism ; Lyases ; metabolism ; Male ; Penis ; enzymology ; physiology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Testosterone ; metabolism

OBJECTIVETo investigate the effect of ursolic acid (UA) on the alloxan-induced kidney injury in diabetic mice and explored its possible mechanisms.

METHODSDiabetes mellitus was induced in male Kunming mice by an injection of alloxan (70 mg/kg, i.v.). After 72 hours, blood glucose levels were detected and mice with blood glucose levels over 13.9 mmol/L were considered as diabetic and selected for further experiment. Thirty mice were randomly divided into three groups: control, diabetic and diabetic + UA(35 mg/kg/d, i.g. continuously for 8 weeks). Blood glucose concentration, organ coefficient of kidney, blood urea nitrogen (BUN), creatinine (Cr) as well as renal tissue levels of superoxide dismutase (SOD), methane dicarboxylic aldehyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined. Pathology of the renal tissue was measured by hematoxylin-eosin staining.

RESULTSCompared to the control group, blood glucose, organ coefficient of kidney, BUN and Cr increased significantly. In addition, SOD activities was reduced markedly and levels of MDA and inflammatory factors (TNF-α, IL-6) increased significantly. Renal cells from model group rats showed atrophy and disordered after HE staining and infiltration of inflammatory cells also appeared in renal tissue of the model group. These changes were significantly attenuated in the diabetic group treated with UA.

CONCLUSIONUA can significantly relieve renal damage in mice with diabetic nephropathy induced by alloxan, which might be related to decreased blood glucose level, antioxidation effect and inhibiting the production of inflammatory factors such as TNF-α and IL-6.

Alloxan ; adverse effects ; Animals ; Antioxidants ; metabolism ; Blood Glucose ; Blood Urea Nitrogen ; Creatinine ; metabolism ; Diabetes Mellitus, Experimental ; physiopathology ; Diabetic Nephropathies ; chemically induced ; drug therapy ; Interleukin-6 ; metabolism ; Kidney ; physiopathology ; Male ; Mice ; Superoxide Dismutase ; metabolism ; Triterpenes ; pharmacology ; Tumor Necrosis Factor-alpha ; metabolism

The aim of the present study is to investigate the effects of sequoyitol (Seq) on expression of eNOS and NOX4 in aortas of type 2 diabetic rats. Type 2 diabetic rats induced by high fat and high sugar diet and low dose of streptozotocin (STZ, 35 mg x kg(-1)) and were administered Seq (12.5, 25 and 50 mg x kg(-1) x d(-1)) for 6 weeks. The fasting blood glucose (FBG) and body weight were tested. Acetylcholine (Ach) induced endothelium-dependent relaxation and sodium nitroprusside (SNP) induced endothelium-independent relaxation were measured in aortas for estimating endothelial function. Aortic morphological change was observed with HE staining. The level of serum insulin was measured by radioimmunoassay. The total antioxidative capacity (T-AOC), malondialdehyde (MDA) and NO levels in aortas were determined according to the manufacturer's instructions. In addition, the expressions of eNOS and NOX4 in aortas were measured by immunohistochemisty, real-time PCR or Western blotting. The results showed that Seq significantly decreased FBG and insulin resistance, and improved aortic endothelium-dependent vasorelaxation function. The expressions of NOX4 and MDA content were obviously decreased, while the expression of eNOS, the levels of NO and T-AOC increased significantly in aortas of diabetic rats with Seq treatment. In conclusion, Seq protects against aortic endothelial dysfunction of type 2 diabetic rats through down-regulating expression of NOX4 and up-regulating eNOS expression.
Animals ; Aorta ; metabolism ; pathology ; Blood Glucose ; metabolism ; Body Weight ; Diabetes Mellitus, Experimental ; chemically induced ; metabolism ; physiopathology ; Diabetes Mellitus, Type 2 ; chemically induced ; metabolism ; physiopathology ; Hypoglycemic Agents ; pharmacology ; Inositol ; analogs & derivatives ; pharmacology ; Insulin ; blood ; Insulin Resistance ; Male ; Malondialdehyde ; metabolism ; NADPH Oxidase 4 ; NADPH Oxidases ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Oxidation-Reduction ; drug effects ; Rats ; Rats, Sprague-Dawley ; Streptozocin ; Vasodilation ; drug effects

We aimed to elucidate the effect of bilirubin on dyslipidemia and nephropathy in a diabetes mellitus (DM) type I animal model. Sprague-Dawley rats were separated into control, DM, and bilirubin-treated DM (Bil) groups. The Bil group was injected intraperitoneally with 60 mg/kg bilirubin 3 times per week and hepatoma cells were cultured with bilirubin at a concentration of 0.3 mg/dL. The Bil group showed lower serum creatinine levels 5 weeks after diabetes onset. Bilirubin treatment also decreased the amount of mesangial matrix, lowered the expression of renal collagen IV and transforming growth factor (TGF)-beta1, and reduced the level of apoptosis in the kidney, compared to the DM group. These changes were accompanied by decreased tissue levels of hydrogen superoxide and NADPH oxidase subunit proteins. Bilirubin decreased serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), free fatty acids, and triglycerides (TGs), as well as the TG content in the liver tissues. Bilirubin suppressed protein expression of LXRalpha, SREBP-1, SCD-1, and FAS, factors involved in TG synthesis that were elevated in the livers of DM rats and hepatoma cells under high-glucose conditions. In conclusion, bilirubin attenuates renal dysfunction and dyslipidemia in diabetes by suppressing LXRalpha and SREBP-1 expression and oxidative stress.
Animals ; Bilirubin/pharmacology/*therapeutic use ; Cell Line, Tumor ; Creatine/blood ; Diabetes Mellitus, Experimental/chemically induced/complications/*pathology ; Diabetic Nephropathies/*drug therapy/etiology ; Disease Models, Animal ; Kidney/pathology ; Lipoproteins, HDL/blood ; Liver/metabolism ; Male ; Mice ; Mice, Inbred C57BL ; NADPH Oxidase/metabolism ; Orphan Nuclear Receptors/antagonists & inhibitors/genetics/metabolism ; Oxidative Stress/drug effects ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species/metabolism ; Streptozocin/toxicity ; Triglycerides/analysis/*biosynthesis/blood

This study is to observe the effects of sequoyitol on the expression of NADPH oxidase subunits p22 phox and p47 phox in rats with type 2 diabetic liver diseases. The model of high fat and high sugar diet as well as intraperitoneal injection of small dose of streptozotocin (STZ, 35 mg x kg(-1)) induced diabetic rat liver disease was used. After sequoyitol (50, 25 and 12.5 mg x kg(-1)) was administrated for 6 weeks, the contents of blood glucose (BG), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total antioxidant capacity (T-AOC), hydrogen peroxide (H2O2), NO and insulin (Ins) were measured, liver p22 phox and p47 phox mRNA content was determined with real-time PCR and the expression of p22 phox and p47 phox protein was examined by Western blotting. In addition, pathological changes in liver were observed with HE staining. Sequoyitol could reduce the content of fasting blood glucose, ALT, AST, Ins and H2O2, restore insulin sensitive index (ISI) and weight, elevate liver tissue T-AOC and NO content, reduce the NADPH oxidase subunit liver tissue p22 phox and p47 phox mRNA and protein expression, as well as ameliorate liver pathologic lesions. The results showed that sequoyitol can ease the type 2 diabetic rat liver oxidative stress by lowering NADPH oxidase expression.
Alanine Transaminase ; blood ; Animals ; Aspartate Aminotransferases ; blood ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; chemically induced ; metabolism ; Hydrogen Peroxide ; metabolism ; Hypoglycemic Agents ; pharmacology ; Inositol ; analogs & derivatives ; pharmacology ; Insulin ; blood ; Liver ; metabolism ; pathology ; Liver Diseases ; metabolism ; Male ; NADPH Oxidases ; genetics ; metabolism ; Nitric Oxide ; metabolism ; Oxidation-Reduction ; drug effects ; Oxidative Stress ; drug effects ; RNA, Messenger ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Streptozocin

Aspirin is a kind of anti-inflammatory drug and may be used to reverse hyperglycemia, hyperinsulinemia, and dyslipidemia by improving insulin resistance. We hypothesized that aspirin improves insulin resistance in type 2 diabetes by inhibiting hepatic nuclear factor kappa-beta (NF-kappaB) activation and serum tumor necrosis factor-alpha (TNF-alpha). Adult male Wistar rats were randomly divided into four groups: control, untreated diabetic, diabetic treated with metformin (100 mg/kg/day), and diabetic treated with aspirin (120 mg/kg/day). Diabetes was induced by high-fat feeding and a low dose of streptozotocin (30 mg/kg). After treatment, plasma glucose, insulin, lipids, free fatty acids (FFAs) concentrations and serum TNF-alpha were determined. The expression of NF-kappaB in hepatocytes was analyzed by immunohistochemistry and western blot. The results showed administration of aspirin caused no significant lowering in fasting glucose level but significant reduction of hepatic NF-kappaB expression and serum TNF-alpha level with improved insulin resistance compared to the diabetic group. The relevant analysis showed positive correlation between the expression of homeostasis model assessment-insulin resistance (HOMA-IR) and NF-kappaB (r = 0.799, P < 0.01); HOMA-IR and serum TNF-alpha (r = 0.790, P < 0.01). It is concluded that aspirin improves insulin resistance by inhibiting hepatic NF-kappaB activation and TNF-alpha level in streptozotocin-induced type 2 diabetic rats.
Animals ; Anti-Inflammatory Agents, Non-Steroidal/*pharmacology ; Aspirin/*pharmacology ; Blood Glucose/analysis ; Diabetes Mellitus, Experimental/blood/chemically induced/*metabolism ; Fatty Acids, Nonesterified/blood ; Hypoglycemic Agents/*pharmacology ; Insulin/blood ; Insulin Resistance ; Liver/metabolism ; Male ; Metformin/therapeutic use ; NF-kappa B/*metabolism ; Rats ; Rats, Wistar ; Tumor Necrosis Factor-alpha/*blood

The aim of this study is to investigate the therapeutic effect of RegIII-proinsulin-pBudCE4.1 plasmid on streptozotocin (STZ)-induced type 1 diabetes mellitus and its underlying mechanisms. The model of type 1 diabetes mellitus was established by intraperitoneal injections of STZ (40 mg kg(-1)) to Balb/c mice for five consecutive days. Then, ten type 1 diabetic mice were intramuscularly injected with 100 microg RegIII-proinsulin-pBudCE4.1 plasmid for 4 weeks (one time/week) and the blood glucose levels were monitored every week; whereas another ten diabetic mice served as negative control group were injected with pBudCE4.1 vector at the same dose. Normal control and model control mice were treated with normal saline at identical volume under the same way. Western blotting, MTT assay, ELISA, HE staining and Tunel assay were applied to explore the underlying mechanisms. Results showed that RegIII-proinsulin-pBudCE4.1 plasmid ameliorated the hyperglycemia symptoms in diabetic mouse remarkably. It induced an immunological tolerance state in type 1 diabetic mice by inhibiting the proliferation of splenic lymphocytes and recovering Th1/Th2 balance evidenced by MTT and ELISA analysis. Furthermore, it elevated insulin concentration in the serum of type 1 diabetic mice and promoted the regeneration of beta cells supported by the results of HE staining and Tunel assay. In conclusion, RegIII-proinsulin-pBudCE4.1 plasmid possesses powerful anti-diabetic ability, which may be involved in the inducing of immunological tolerance and enhancing beta cells recovery.
Animals ; Apoptosis ; Blood Glucose ; metabolism ; Cell Proliferation ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; therapy ; Diabetes Mellitus, Type 1 ; chemically induced ; metabolism ; pathology ; therapy ; Genetic Therapy ; Hyperglycemia ; therapy ; Injections, Intramuscular ; Insulin ; blood ; Islets of Langerhans ; cytology ; Male ; Mice ; Mice, Inbred BALB C ; Plasmids ; Proinsulin ; genetics ; metabolism ; therapeutic use ; Proteins ; genetics ; metabolism ; therapeutic use ; Streptozocin ; T-Lymphocytes ; cytology ; Th1-Th2 Balance

An alpha-amylase inhibitor (alpha-AI) was isolated from white kidney beans (Phaseolus vulgaris L) by ethanol fractional precipitation, ion exchange chromatography and gel filtration column chromatography. It was a homogeneity glycoprotein demonstrated by SDS-PAGE and gel filtration on CL-6B. The glycoprotein contained 88.2% protein and was rich in aspartic acid, glutamic acid, leucine, threonine and serine. The carbohydrate moiety was consisted of Man, Glc, Gal and Xyl in a mole ratio of 2.42: 1.50: 1.52: 1.00. The glycan and the core protein backbone was connected by O-linkage as determined by beta-elimination reaction. The continuous oral administration of the alpha-AI (150 mg x kg(-1) x d(-1)) for 7 days can lower fasting blood glucose and 300 mg x kg(-1) x d(-1) alpha-AI for 7 days can improve the sugar tolerance on alloxan-dependent diabetic model rats. The result showed the alpha-AI obtained from white kidney beans had good hypoglycemic effect on alloxan induced diabetic rats and may have high potential pharmaceutical value as a regulative digestive-starch degradation in patients suffering from diabetes.
Alloxan ; Amino Acids ; analysis ; Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; blood ; chemically induced ; Female ; Glycoproteins ; chemistry ; isolation & purification ; pharmacology ; Molecular Weight ; Monosaccharides ; analysis ; Phaseolus ; chemistry ; Plant Lectins ; chemistry ; isolation & purification ; pharmacology ; Plants, Medicinal ; chemistry ; Rats ; Rats, Sprague-Dawley ; Vegetable Proteins ; analysis ; alpha-Amylases ; antagonists & inhibitors

Polysaccharide sulfate (PSS) is a new type of antiatherosclerotic medicine for its effects of anticoagulation, anti-thrombosis and modulation of dyslipidemia. However, it is still uncertain whether PSS could modulate the diabetic dyslipidemia or not. Here, the rat model of diabetic dyslipidemia was developed and the effects of PSS on glucose and lipid levels were investigated in this animal model. Wistar rats were iv injected with streptozotocin 20 mg x kg(-1) after feeding with high fat diet for one and a half month. Then, rats received orally PSS (30, 90, and 180 mg x kg(-1)) for 1 month. After oral treatment with PSS (90 and 180 mg x kg(-1)) for 1 month, the levels of triglyceride (TG), total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C) were significantly reduced and the level of high density lipoprotein-cholesterol (HDL-C) increased, compared with diabetic control rats. Moreover, PSS (30, 90, and 180 mg x kg(-1)) had a tendency to reduce glucose and insulin levels, and significantly increased insulin sensitivity index. Our results suggest that PSS could improve insulin sensitivity and relieve dyslipidemia in diabetic dyslipidemic rats.
Administration, Oral ; Animals ; Blood Glucose ; metabolism ; Cholesterol, HDL ; blood ; Cholesterol, LDL ; blood ; Diabetes Mellitus, Experimental ; blood ; chemically induced ; complications ; Dyslipidemias ; blood ; etiology ; Hypolipidemic Agents ; administration & dosage ; pharmacology ; Insulin ; blood ; Insulin Resistance ; Male ; Polysaccharides ; administration & dosage ; pharmacology ; Random Allocation ; Rats ; Rats, Wistar ; Streptozocin ; Sulfates ; administration & dosage ; pharmacology ; Triglycerides ; blood