Calpain activation contributes to hyperglycemia-induced endothelial dysfunction and apoptosis. This study was designed to investigate the role of calpain inhibition in improving diabetic erectile dysfunction (ED) in mice. Thirty-eight-week-old male C57BL/6J mice were divided into three groups: (1) nondiabetic control group, (2) diabetic mice + vehicle group, and (3) diabetic mice + MDL28170 (an inhibitor of calpain) group. Type 1 diabetes was induced by intraperitoneal injection of streptozotocin at 60 mg kg^-1 body weight for 5 consecutive days. Thirteen weeks later, diabetic mice were treated with MDL28170 or vehicle for 4 weeks. The erectile function was assessed by electrical stimulation of the cavernous nerve. Penile tissues were collected for measurement of calpain activity and the endothelial nitric oxide synthase (eNOS)-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway. Terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling (TUNEL) staining was used to evaluate apoptosis. Caspase-3 expression and activity were also measured to determine apoptosis. Our results showed that erectile function was enhanced by MDL28170 treatment in diabetic mice compared with the vehicle diabetic group. No differences in calpain-1 and calpain-2 expressions were observed among the three groups. However, calpain activity was increased in the diabetic group and reduced by MDL28170. The eNOS-NO-cGMP pathway was upregulated by MDL28170 treatment in diabetic mice. Additionally, MDL28170 could attenuate apoptosis and increase the endothelium and smooth muscle levels in corpus cavernosum. Inhibition of calpain could improve erectile function, probably by upregulating the eNOS-NO-cGMP pathway and reducing apoptosis.
Animals ; Apoptosis/drug effects* ; Calpain/antagonists & inhibitors* ; Cyclic GMP/biosynthesis* ; Diabetes Complications/drug therapy* ; Diabetes Mellitus, Experimental/complications* ; Dipeptides/therapeutic use* ; Endothelium/metabolism* ; Enzyme Inhibitors/therapeutic use* ; Erectile Dysfunction/etiology* ; In Situ Nick-End Labeling ; Male ; Mice ; Mice, Inbred C57BL ; Muscle, Smooth/metabolism* ; Nitric Oxide Synthase Type III/biosynthesis* ; Penis/enzymology* ; Up-Regulation

INTRODUCTIONThis study was designed and conducted to evaluate the effects of vitamin A, C and E supplementation, and omega-3 fatty acid supplementation on the activity of paraoxonase and arylesterase in an experimental model of diabetes mellitus.

METHODSA total of 64 male Sprague Dawley® rats, each weighing 250 g, were randomly distributed into four groups: (a) normal control; (b) diabetic control; (c) diabetic with vitamin A, C and E supplementation; and (d) diabetic with omega-3 fatty acid supplementation. The animals were anaesthetised after four weeks of intervention, and paraoxonase and arylesterase activity in blood plasma, and liver and heart homogenates were measured.

RESULTSArylesterase activity in the heart and liver homogenates was significantly lower in the diabetic control group than in the normal control group (p < 0.01). Vitamin A, C and E supplementation, and omega-3 fatty acid supplementation significantly increased liver arylesterase activity (p < 0.05). No significant change was observed in paraoxonase activity and other investigated factors.

CONCLUSIONVitamin A, C and E, or omega-3 fatty acid supplementation were found to increase liver arylesterase activity in streptozotocin-induced diabetic rats. These supplements may be potential agents for the treatment of diabetes mellitus complications.

Animals ; Aryldialkylphosphatase ; metabolism ; Ascorbic Acid ; pharmacology ; Carboxylic Ester Hydrolases ; metabolism ; Diabetes Mellitus, Experimental ; diet therapy ; metabolism ; Dietary Supplements ; Fatty Acids, Omega-3 ; pharmacology ; Liver ; enzymology ; Male ; Myocardium ; enzymology ; Rats ; Rats, Sprague-Dawley ; Vitamin A ; pharmacology ; Vitamins ; pharmacology

UNLABELLEDOCTOBER: To explore the effects of the glucagon-like peptide 1 (GLP-1) liraglutide on the penile erectile function of rats with diabetic erectile dysfunction (DED) by observing the impact of liraglutide on the expression of eNOS in the corpus cavernosum of diabetic rats.

METHODSWe randomly divided 30 six-week-old male SD rats into a normal control (n = 10) and an experimental group (n = 20) , established models of diabetes mellitus (DM) in the experimental rats, and subdivided them into a DM (n = 8) and a GLP-1 group (n = 8) to receive intramuscular injection of normal saline and liraglutide at 5 mg per kg of the body weight per day, respectively. After 12 weeks of intervention, we obtained the levels of FPG, FINS, TG, TC, HDL-C, LDL-C, testosterone, and IL-6 and the indexes of Homa-IR and Homa-β, detected the expressions of Akt/p-Akt and eNOS/p-eNOS in the corpus cavernosum by Western blot, and compared the erectile function between different groups.

RESULTSThe frequency and rate of penile erection were significantly lower in the DM group than in the GLP-1 and normal control groups (P < 0.05) and also lower in the GLP-1 group than in the normal controls (P < 0.05). Immunofluorescence staining showed the expression of eNOS mainly in the cytoplasm of the cavernosal vessels and sinusoidal endothelial cells, markedly lower in the DM and GLP-1 groups than in the normal rats (P < 0.05), but higher in the GLP-1 than in the DM group (P < 0.05). The level of eNOS/p-eNOS in the penile tissue was significantly decreased in the DM and GLP-1 groups in comparison with the normal controls (P < 0.01 or P < 0.05), while that of p-eNOS was markedly increased in the GLP-1 group as compared with the DM group (P < 0.05). No statistically significant differences were observed in the Akt level among the three groups of animals (P > 0.05). The expression of p-Akt was remarkably reduced in the DM and GLP-1 groups in comparison with the control rats (P < 0.01 or P < 0.05), but higher in the GLP-1 than in the DM group (P < 0.05).

CONCLUSIONGLP-1 can protect the function of endothelial cells in the corpus cavernosum and improve the erectile function of DED rats by regulating the Akt/ eNOS signaling pathway, which indicates that GLP-1 could be an important option for the treatment and prevention of DED.

Animals ; Blotting, Western ; Diabetes Mellitus, Experimental ; Erectile Dysfunction ; drug therapy ; enzymology ; Hypoglycemic Agents ; pharmacology ; Liraglutide ; pharmacology ; Male ; Nitric Oxide Synthase Type III ; metabolism ; Penile Erection ; drug effects ; Penis ; drug effects ; enzymology ; physiopathology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Testosterone ; blood

We assessed the effects of furan and lycopene on the histopathological and biochemical changes on lungs, body and lung weights, and food consumption of rats. Furan and diabetes caused histopathological changes, increment in malondialdehyde levels, and decrease in antioxidant enzyme activities. Lycopene showed a protective effect against these damages, except for glutathione-S-transferase and glutathione peroxidase activities. Consequently, furan and diabetes resulted in lung toxicity. Our findings demonstrate that furan treatment resulted in more alterations in histology and biochemical parameters in diabetic rats and lycopene showed protective effects against these alterations.
Animals ; Antioxidants ; pharmacology ; Carotenoids ; pharmacology ; Diabetes Mellitus, Experimental ; enzymology ; pathology ; Furans ; toxicity ; Lung ; drug effects ; enzymology ; pathology ; Male ; Rats, Wistar

OBJECTIVETo investigate the role of integrin-linked kinase (ILK) signaling pathway in the skin lesions and wound healing in diabetic rats.

METHODSThirty-six SD rats were divided into diabetic wound group (D) and non-diabetic wound group (N) according to the random number table, with 18 rats in each group. 10 g/L streptozocin (60 mg/kg) was intraperitoneally injected in rats in group D, while the rats in group N were given same quantity of sodium citrate buffer. Two weeks after successful reproduction of diabetic model of rats in group D, two full-thickness skin of an area of 2 cm × 2 cm was resected on both sides of back of rats in the two groups. Wounds of three rats of each group were photographed and examined on post injury day (PID) 1, 3, 7, 10, 14, and 21, and the wound healing rates were calculated. The non-injured skin and wound tissue (central part) on back of three rats of the rest 15 rats in the two groups were harvested on PID 3, 7, 10, 14, and 21, respectively. Morphology of the non-injured skin tissue was observed with HE staining, and the thickness of full-thickness skin and epidermis were measured. The mRNA expression levels of ILK, protein kinase B (Akt), and glycogen synthase kinase-3β (GSK-3β) in non-injured skin tissue were determined with real-time fluorescent quantitative RT-PCR. The protein expression levels of ILK, Akt, phosphorylated Akt, GSK-3β, and phosphorylated GSK-3β in non-injured skin tissue, and ILK, phosphorylated Akt in wound tissue were assessed with Western blotting. Data were processed with two independent-sample t test, one-way analysis of variance, SNK test and analysis of variance of factorial design.

RESULTS(1) After injury, the wound scabs of rats in group N were dry, and red granulation tissue with no excretion were seen when the scabs fell off, and the wound healed fast. After injury, excretion under the wound scabs of rats in group D was seen, and the scabs easily fell off with exposure of pink granulation tissue with much excretion, and the wounds healed slowly. Except for PID 3, the wound healing rate of rats in group D was significantly lower than that in group N on other PIDs (with t values from 3.858 to 13.738, P<0.05 or P<0.01). (2) On PID 3, the hair follicles and blood vessels in the non-injured skin tissue of rats in group N were rich, and the epidermis was composed of stratified cells in form of basal cells and keratinocyte, and the hair follicles and blood vessels in the non-injured skin tissue of rats in group D were scarce, and the epidermis was nearly composed of one-layer of cells. The thickness of full-thickness skin and epidermis of non-injured skin tissue of rats in group N was similar from PID 3 to 21, and the thickness of full-thickness skin and epidermis of non-injured skin tissue of rats in group D on PID 3 was respectively (1 074 ± 66) and (15.1 ± 3.8) μm, and they gradually thinned out to (785 ± 122) and (9.7 ± 2.1) μm on PID 21, respectively. The thickness of full-thickness skin and epidermis of non-injured skin tissue of rats in group N were significantly thicker than those in group D on each PID (with t values from 4.620 to 23.549, P values below 0.001). (3) From PID 3 to 21, the mRNA expression levels of ILK and Akt in non-injured skin tissue of rats in group D were significantly lower than those in group N (with t values respectively 4.779 and 3.440, P values below 0.05), the mRNA expression levels of GSK-3β in non-injured skin tissue of rats were similar in two groups (t=0.363, P>0.05). (4) From PID 3 to 21, the protein expression levels of ILK, Akt and phosphorylated Akt in non-injured skin tissue of rats in group D were significantly lower than those in group N (with t values from 2.630 to 6.209, P<0.05 or P<0.01); the protein expression levels of GSK-3β in non-injured skin tissue of rats in two groups were similar (t=0.652, P>0.05); the protein expression level of phosphorylated GSK-3β in non-injured skin tissue of rats in group D was significantly higher than that in group N (t=4.131, P<0.001). The protein expression levels of ILK in wound tissue of rats in two groups were similar on each PID (with t values from 0.381 to 2.440, P values above 0.05). Except for PID 3, the protein expression levels of phosphorylated Akt in wound tissue of rats in group N were significantly higher than that in group D on other PIDs (with t values from 4.091 to 20.555, P<0.05 or P<0.01). From PID 3 to 21, the protein expression levels of ILK in wound tissue and non-injured skin tissue of rats in group N were similar (F=2.522, P>0.05), and the protein expression level of phosphorylated Akt in wound tissue was significantly higher than that in non-injured skin tissue (F=117.329, P<0.001); the protein expression levels of ILK in wound tissue and non-injured skin tissue of rats in group D were similar (F=1.337, P>0.05), and the protein expression level of phosphorylated Akt in wound tissue was significantly higher than that in non-injured skin tissue (F=184.120, P<0.001).

CONCLUSIONSThe skin lesion of diabetic rats may be related to the declined expression levels of ILK, Akt and phosphorylated Akt in the ILK signaling pathway. The refractory healing of wound in diabetic rats may be related to the declined expression level of phosphorylated Akt.

Animals ; Diabetes Mellitus, Experimental ; enzymology ; Glycogen Synthase Kinase 3 ; metabolism ; Glycogen Synthase Kinase 3 beta ; Phosphorylation ; Protein-Serine-Threonine Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Skin ; injuries ; Wound Healing

The present study aimed at determining whether berberine can enhance the antidiabetic effects and alleviate the adverse effects of canagliflozin in diabetes mellitus. Streptozotocin-induced diabetic mice were introduced, and the combined effects of berberine and canagliflozin on glucose metabolism and kidney functions were investigated. Our results showed that berberine combined with canagliflozin (BC) increased reduction of fasting and postprandial blood glucose, diet, and water intake compared with berberine or canagliflozin alone. Interestingly, BC showed greater decrease in blood urea nitrogen and creatinine levels and lower total urine glucose excretion than canagliflozin alone. In addition, BC showed increased phosphorylated 5' AMP-activated protein kinase (pAMPK) expression and decreased tumor necrosis factor alpha (TNFα) levels in kidneys, compared with berberine or canagliflozin alone. These results indicated that BC was a stronger antidiabetic than berberine or canagliflozin alone with less negative side effects on the kidneys in the diabetic mice. The antidiabetic effect was likely to be mediated by synergically promoting the expression of pAMPK and reducing the expression of TNFα in kidneys. The present study represented the first report that canagliflozin combined with berberine was a promising treatment for diabetes mellitus. The exact underlying mechanisms of action should be investigated in future studies.
AMP-Activated Protein Kinases ; metabolism ; Animals ; Berberine ; administration & dosage ; Blood Glucose ; metabolism ; Canagliflozin ; administration & dosage ; adverse effects ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; Drug Therapy, Combination ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Hypoglycemic Agents ; administration & dosage ; Insulin ; metabolism ; Kidney ; drug effects ; enzymology ; metabolism ; Male ; Mice ; Streptozocin

OBJECTIVETo investigate the effect of Dan-gua Fang on adenosine 5'-monophosphate (AMP) activated protein kinase (AMPK) α expression in liver and subsequent improvement of glucose and lipid metabolism.

METHODSForty 13-week-old diabetic Goto-Kakizaki (GK) rats were randomly divided into model, Dan-gua Fang, metformin and simvastatin groups (n=10 for each), and fed high-fat diet ad libitum. Ten Wistar rats were used as normal group and fed normal diet. After 24 weeks, liver expression of AMPKα mRNA was assessed by real-time PCR. AMPKα and phospho-AMPKα protein expression in liver was evaluated by Western blot. Liver histomorphology was carried out after hematoxylin-eosin staining, and blood glucose (BG), glycosylated hemoglobin A1c (HbA1c), food intake and body weight recorded.

RESULTSSimilar AMPKα mRNA levels were found in the Dan-gua Fang group and normal group, slightly higher than the values obtained for the remaining groups (P<0.05). AMPKα protein expression in the Dan-gua Fang group animals was similar to other diabetic rats, whereas phospho-AMPKα (Thr-172) protein levels were markedly higher than in the metformin group and simvastatin group (P<0.05), respectively. However, phosphor-AMPKα/AMPKα ratios were similar in all groups. Dan-gua Fang reduced fasting blood glucose with similar strength to metformin, and was superior in reducing cholesterol, triglycerides, high-density lipoprotein cholesterol as well as improving low-density lipoprotein cholesterol in comparison with simvastatin and metformin. Dan-gua Fang decreases plasma alanine aminotransferase (ALT) significantly.

CONCLUSIONDan-gua Fang, while treating phlegm-stasis, could decrease BG and lipid in type 2 diabetic GK rats fed with high-fat diet, and effectively protect liver histomorphology and function. This may be partly explained by increased AMPK expression in liver. Therefore, Dan-gua Fang might be an ideal drug for comprehensive intervention for glucose and lipid metabolism disorders in type 2 diabetes mellitus.

AMP-Activated Protein Kinases ; genetics ; metabolism ; Animals ; Blood Glucose ; metabolism ; Body Weight ; Diabetes Mellitus, Experimental ; blood ; drug therapy ; enzymology ; metabolism ; Drugs, Chinese Herbal ; therapeutic use ; Feeding Behavior ; Glycolipids ; metabolism ; Liver ; enzymology ; pathology ; Male ; Phosphorylation ; RNA, Messenger ; genetics ; metabolism ; Rats, Wistar ; Real-Time Polymerase Chain Reaction ; Time Factors

INTRODUCTIONDiabetes mellitus induces microangiopathic changes that lead to endothelial dysfunction. This study investigated the effect of Xiaokening, a type of Chinese compound medicine, on the mesenteric arteriolar endothelial cell function of diabetic rats and its underlying mechanism.

METHODSDiabetes mellitus was induced in rat models via intraperitoneal injection of 60 mg/kg streptozotocin and observed over three weeks. Mesenteric arterioles, which were isolated in a cannulated and pressurised state, were incubated with intravascular injections of 1, 3 or 5 g/L Xiaokening for 24, 48 or 72 hours. The effects of Xiaokening on the release of nitric oxide (NO) on the mesenteric arterioles were detected under shear stress of 1, 10 and 20 dyn/cm(2). Biochemical methods were used to determine the activities of superoxide dismutase (SOD) and xanthine oxidase (XO). The expressions of endothelial NO synthase (eNOS), SOD and XO in the mesenteric arterioles were assessed using Western blot.

RESULTSCompared to normal rat arterioles, less NO was released in the mesenteric arterioles of diabetic rats. Xiaokening was found to have a concentration- and time-dependent effect on NO release; when the shear stress was increased, there was a gradual increase in the release of NO. Compared to normal arterioles, the expression of eNOS in the mesenteric arterioles of diabetic rats was lower. Incubation with Xiaokening increased SOD activity and expression, and decreased XO activity and expression in the mesenteric arterioles of the diabetic rats.

CONCLUSIONXiaokening was able to significantly increase NO release and improve the endothelial function of mesenteric arterioles through antioxidative mechanisms.

Animals ; Antioxidants ; chemistry ; Arterioles ; enzymology ; Diabetes Mellitus, Experimental ; drug therapy ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; pharmacology ; Endothelial Cells ; drug effects ; Injections, Intraperitoneal ; Male ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Oxygen ; metabolism ; Rats ; Rats, Sprague-Dawley ; Streptozocin ; Superoxide Dismutase ; metabolism ; Xanthine Oxidase ; metabolism

The purpose of this study was to investigate the change of aortic semicarbazide-sensitive amine oxidase (SSAO) activity in diabetic rats and examine the effect of 2-bromoethylamine (2-BEA) on SSAO activity and vascular endothelium in diabetic rats. SSAO was prepared from rat aorta. For assessment of the inhibitory effect, the enzymes were preincubated in the presence of different concentrations of 2-BEA before the addition of benzylamine in vitro. Type 1 diabetic rat model was induced by a single intraperitoneal injection of streptozotocin (STZ). Sprague Dawley (SD) rats were randomly divided into normal control group (NC), diabetic model group (DM), 2-BEA 5 mg/kg group, 2-BEA 20 mg/kg group (n = 10 in each group). 2-BEA was administered daily via intraperitoneal injection for 8 weeks. At the end of 8 weeks, blood sample was collected from the abdominal aorta. Plasma nitric oxide (NO) was determined by nitrate reductase method. Plasma endothelin-1 (ET-1) was determined by radioimmunoassay. Aorta SSAO was determined by high performance liquid chromatography. The aorta was prepared to observe morphological changes and ultramicroscopic structures. The results were as follows: Compared with NC group, aortic SSAO activity and the plasma ET-1 were significantly increased (P < 0.01), and plasma NO was significantly decreased (P < 0.01) in DM group. 2-BEA decreased plasma ET-1 and elevated plasma NO by inhibiting aortic SSAO activity in diabetic rats (P < 0.01), and 2-BEA 20 mg/kg group was more significant than 2-BEA 5 mg/kg group (P < 0.05). Endothelial injury of 2-BEA group rats was less serious than DM group. These results suggest that 2-BEA protect aortic endothelium by inhibiting aortic SSAO activity.
Amine Oxidase (Copper-Containing) ; metabolism ; Animals ; Aorta, Abdominal ; enzymology ; Diabetes Mellitus, Experimental ; enzymology ; Endothelin-1 ; blood ; Endothelium, Vascular ; drug effects ; Ethylamines ; pharmacology ; Protective Agents ; pharmacology ; Rats ; Rats, Sprague-Dawley

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