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

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

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

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

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

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

AIMTo evaluate the roles of puerarin in alleviating the STZ-induced lung injury.

METHODSDM model was established by streptozotocin (STZ) intraperitoneal injection to study the injury mechanisms of the lung. SD rats were divided randomly into control group (C group), diabetes group (DM group), diabetes + puerarin group (DM + Pur group). The blood glucose and weight were observed and recorded before and the 20 th, 40 th, 60 thd after administration of saline, STS, STZ+ Pur. Contents of NO and malondialdehyde (MDA) and activity of superoxide dismutase (SOD) were measured in lung tissues. Light microscope (LM), transmission electron microscope (TEM) and immunohistochemical analysis were also used.

RESULTS(1) Compared with control group, the contents of NO and MDA were increased significantly (P < 0.01), while the activity of SOD reduced (P < 0.05). Compared with DM group, treatment with puerarin inhibited the increase of NO level (P < 0.01), and MDA content began to decline from 40 days after the model was established (P < 0.01), and inhibited the decrease of SOD activity induced by DM (P < 0.01). (2) LM and TEM results showed that alveolar and capillary basement membrane became thick, the number of tiny villus decreased markedly, the quantity of osmiophilic multilamellar body reduced remarkably, hyperplasia was shown in collgen fibre. Puerarin could alleviate above injuries induced by DM. (3) Immunohistochemical staining results showed that mild brown positive stain of NT could be seen in protoplasm of lung tissues. STZ administration induced the expression of NT in the protoplasm of cells, and led to stronger positive signals of NT than that of control group. Treatment with puerarin weakened the positive stain of NT.

CONCLUSION(1) DM induced by STZ leads to a significant and sustained increase in blood glucose and obvious lung injury, which may be associated with the overproduction of free radicals. (2) The pathway of NO/ONOO- is one of the injury mechanisms of the lung tissues cells. (3) Puerarin suppresses the expression of NT and elevates the activity of SOD. Thereby, resulting in the reduces of the production of free radicals, which may be one of the mechanisms of its anti-oxidative-injuries.

Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; Isoflavones ; pharmacology ; Lung ; metabolism ; pathology ; Lung Injury ; chemically induced ; Malondialdehyde ; analysis ; Nitric Oxide ; analysis ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism

OBJECTIVETo study the hypoglycemic effect of the extract of B. polyandra (SHG).

METHODThe diabetic mice were induced by alloxan in ICR mice. The blood glucose concentration was measured by glucose oxidase method. The serum insulin level was determined by 125I-insulin radioimmunoassay kit. The hypoglycemic effect was evaluated by the levels of both fasting and no-fasting blood glucose. The effect on serum insulin level was estimated by the values of the blood insulin and the changes of the blood glucose induced by the glucose intraperitoneal injection. The effect on the glucose absorption was investigated by the oral sucrose or starch tolerance test.

RESULTBoth of the fasting and no-fasting blood glucose levels were decreased significantly by the treatment of 20 or 30 g raw materials crude drug x kg (-1) SHG orally for 7-10 d in ICR mice or in alloxan diabetic mice. In the oral sucrose tolerance test or oral starch tolerance test, the administration of SHG reduced significantly the peak value of the blood glucose and the area under the blood glucose-time curve (AUC) in normal or alloxan diabetic mice, respectively. These effects of SHG were similar to those of acarbose, a kind of alpha-glucosidase inhibitors. In the oral glucose tolerance test in normal and alloxan diabetic mice, SHG decreased both the blood glucose peak and the AUC induced by the glucose loading. But in the intraperitoneal injection glucose tolerance test the levels of insulin in both SHG and control mice were similar, however, the changes of the blood glucose level after the glucose-loading for 30 min in SHG mice was much lower than that in control mice.

CONCLUSIONWith the treatment of SHG, the fasting and no-fasting blood glucose concentrations were decreased and the glucose tolerance improved significantly in both normal and alloxan diabetic mice, and the inhibition of a-glucosidase might be one of its major mechanisms.

Administration, Oral ; Alloxan ; Animals ; Area Under Curve ; Blood Glucose ; analysis ; Diabetes Mellitus, Experimental ; blood ; chemically induced ; Drugs, Chinese Herbal ; administration & dosage ; isolation & purification ; pharmacology ; Glucose ; administration & dosage ; pharmacokinetics ; Glucose Tolerance Test ; Hypoglycemic Agents ; administration & dosage ; isolation & purification ; pharmacology ; Injections, Intraperitoneal ; Insulin ; blood ; Male ; Mice ; Mice, Inbred ICR ; Phytotherapy ; Plants, Medicinal ; chemistry ; Random Allocation ; alpha-Glucosidases ; metabolism