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

The aim of this study was to determine the effect of dexamethasone (DEX) on renal ischemia/reperfusion injury (IRI). C57BL/6 mice were randomly divided into Sham group, IRI group and DEX group. The mice in IRI and DEX groups subjected to renal ischemia for 60 min, were treated with saline or DEX (4 mg/kg, i.p.) 60 min prior to I/R. After 24 h of reperfusion, the renal function, renal pathological changes, activation of extracellular signal-regulated kinase (ERK) and glucocorticoid receptor (GR), and the levels of iNOS and eNOS were detected. The results showed DEX significantly decreased the damage to renal function and pathological changes after renal IRI. Pre-treatment with DEX reduced ERK activation and down-regulated the level of iNOS, whereas up-regulated the level of eNOS after renal IRI. DEX could further promote the activation of GR. These findings indicated GR activation confers preconditioning-like protection against acute IRI partially by up-regulating the ratio of eNOS/iNOS.
Animals ; Dexamethasone ; pharmacology ; Gene Expression Regulation, Enzymologic ; drug effects ; Glucocorticoids ; pharmacology ; Male ; Mice ; Nitric Oxide Synthase Type II ; biosynthesis ; Nitric Oxide Synthase Type III ; biosynthesis ; Receptors, Glucocorticoid ; agonists ; Reperfusion Injury ; enzymology ; pathology ; Up-Regulation ; drug effects

The purpose of this study was to devise an expanded ischemic flap model and to investigate the role of AMD-3100 (Plerixafor, chemokine receptor 4 inhibitor) in this model by confirming its effect on mobilization of stem cells from the bone marrow. Male Sprague-Dawley rats were used as an animal research model. The mobilization of stem cells from the bone marrow was confirmed in the AMD-3100-treated group. The fractions of endothelial progenitor cells (EPC) and the vascular endothelial growth factor receptor (VEGFR) 2+ cells in the peripheral blood were increased in groups treated with AMD-3100. The expression of vascular endothelial growth factor (VEGF) was increased in response to expansion or AMD injection. The expression of stromal cell derived factor (SDF)-1 and VEGFR2 were increased only in unexpanded flap treated with AMD-3100. Treatment with AMD-3100 increased both the number and area of blood vessels. However, there were no statistically significant differences in the survival area or physiologic microcirculation in rats from the other groups. This endogenous neovascularization induced by AMD-3100 may be a result of the increase in both the area and number of vessels, as well as paracrine augmentation of the expression of VEGF and EPCs. However, the presence of a tissue expander under the flap could block the neovascularization between the flap and the recipient regardless of AMD-3100 treatment and expansion.
Animals ; Anti-HIV Agents/pharmacology ; Bone Marrow Cells/cytology ; Chemokine CXCL12/biosynthesis ; Endothelial Progenitor Cells/*cytology ; Hematopoietic Stem Cells/*cytology ; Heterocyclic Compounds/*pharmacology ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism ; Male ; Neovascularization, Physiologic ; Nitric Oxide Synthase Type III/metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, CXCR4/antagonists & inhibitors ; Surgical Flaps/*blood supply/surgery ; Tissue Expansion/*methods ; Vascular Endothelial Growth Factor A/biosynthesis ; Vascular Endothelial Growth Factor Receptor-2/biosynthesis/metabolism

The endothelial nitric oxide synthase (eNOS) gene plays an important role in several biological functions. Polymorphisms of the eNOS gene have been associated with cancer. It has been suggested that the VNTR 4 a/b polymorphism may affect the expression of eNOS and contributes to tumor promotion in the mammary gland. We examined the role of the eNOS4 a/b polymorphism by comparing the genotypes of 281 healthy Mexican women with the genotypes of 429 Mexican women with breast cancer (BC). The observed genotype frequencies for control and BC patients were 0.6% and 0.7% for a/a (polymorphic); 87% and 77% for a/a (wild type); and 12% and 22% for a/b respectively. We found that the odds ratio (OR) was 1.9, with a 95% confidence interval (95%CI) of 1.29-2.95, P = 0.001 for genotypes a/a-a/b, b/c. The association was also evident when comparing the distribution of the a/a-a/b genotypes in patients with high levels of glutamate-oxaloacetate transaminase (SGOT) (OR, 1.93; 95% CI, 1.14-3.28; P = 0.015); undergoing menopause with high levels of SGOT (OR, 2.0; 95% CI, 1.1-3.84); and with high levels of glutamic-pyruvic transaminase (SGPT) (OR, 3.5; 95% CI, 1.56-8.22). The genotypes a/a-a/b are associated with BC susceptibility in the analyzed samples from the Mexican population.
Adult ; Alanine Transaminase/*blood ; Aspartate Aminotransferases/*blood ; Breast Neoplasms/*blood/*genetics ; Female ; Gene Frequency ; Genetic Predisposition to Disease ; Genotype ; Humans ; Mexico ; Middle Aged ; Nitric Oxide/biosynthesis/metabolism ; Nitric Oxide Synthase Type III/*genetics ; Polymorphism, Single Nucleotide

This paper aims to investigate the effect of store-operated calcium channels (SOC) and receptor-operated calcium channels (ROC) on Ca(2+)-sensing receptor (CaR)-induced extracellular Ca(2+) influx and nitric oxide (NO) generation in human umbilical vein endothelial cells (HUVEC). SOC blocker, non-selective cation channel blocker, ROC agonist and ROC blocker were used separately and combined. Intracellular Ca(2+) concentration ([Ca(2+)]i) was measured by Fura-2/AM loading. The activity of endothelial nitric oxide synthase (eNOS) and the production of NO were determined by the DAF-FM diacetate (DAF-FM DA). The results showed that increases of [Ca(2+)]i, eNOS activity and NO generation induced by CaR agonist Spermine were all reduced after single blocking the SOC or ROC, respectively (P < 0.05). ROC agonist can partially abolish the ROC blocker's effect (P < 0.05). The above mentioned effects evoked by CaR agonist Spermine were further reduced when blocking both SOC and ROC than single blocking SOC or ROC in HUVEC (P < 0.05). In conclusion, these results suggest that the SOC and ROC participate in the processes of CaR-evoked extracellular Ca(2+) influx and NO generation by a synergistic manner in HUVEC.
Calcium ; physiology ; Calcium Channel Blockers ; pharmacology ; Calcium Channels ; physiology ; Calcium Signaling ; Fluoresceins ; pharmacology ; Human Umbilical Vein Endothelial Cells ; physiology ; Humans ; Nitric Oxide ; biosynthesis ; Nitric Oxide Synthase Type III ; metabolism ; Receptors, Calcium-Sensing ; physiology

Arginase competitively inhibits nitric oxide synthase (NOS) via use of the common substrate L-arginine. Arginase II has recently reported as a novel therapeutic target for the treatment of cardiovascular diseases such as atherosclerosis. Here, we demonstrate that piceatannol-3'-O-beta-D-glucopyranoside (PG), a potent component of stilbenes, inhibits the activity of arginase I and II prepared from mouse liver and kidney lysates, respectively, in a dose-dependent manner. In human umbilical vein endothelial cells, incubation of PG markedly blocked arginase activity and increased NOx production, as measured by Griess assay. The PG effect was associated with increase of eNOS dimer ratio, although the protein levels of arginase II or eNOS were not changed. Furthermore, isolated mice aortic rings treated with PG showed inhibited arginase activity that resulted in increased nitric oxide (NO) production upto 78%, as measured using 4-amino-5-methylamino-2',7'-difluorescein (DAF-FM) and a decreased superoxide anions up to 63%, as measured using dihydroethidine (DHE) in the intact endothelium. PG showed IC50 value of 11.22 microM and 11.06 microM against arginase I and II, respectively. PG as an arginase inhibitor, therefore, represents a novel molecule for the therapy of cardiovascular diseases derived from endothelial dysfunction and may be used for the design of pharmaceutical compounds.
Animals ; Aorta/drug effects/metabolism ; Arginase/*antagonists & inhibitors/metabolism ; Dose-Response Relationship, Drug ; Endothelial Cells/drug effects/enzymology ; Enzyme Activation/drug effects ; Glucosides/chemistry/*pharmacology ; Humans ; Mice ; Mice, Inbred C57BL ; Nitrates/metabolism ; Nitric Oxide/biosynthesis ; Nitric Oxide Synthase Type III/*metabolism ; Nitrites/metabolism ; Reactive Oxygen Species/metabolism ; Rheum/*chemistry ; Stilbenes/chemistry/*pharmacology

OBJECTIVETo investigate the renoprotective effect of adiponectin in streptozotocin (STz)-induced diabetic rats and explore its association with oxidation stress.

METHODSType 2 diabetes mellitus was induced in rats by high-lipids and high-sucrose feeding and intraperitoneal STZ injection. The recombinant plasmid pIRES2-EGFP-gAd expressing globular adiponectin was intraperitoneally injected in the rats mediated by liposome. Thirty-two Wistar rats were randomized into 4 groups, namely the normal control group (NC), diabetic group without any therapy (DM), diabetic group treated with pIRES2-EGFP-gAd (DA) and diabetic group treated with pIRES2-EGFP (DP). After the corresponding treatments for 8 weeks, the blood glucose, HbA1c and urine albumin excretion rate (UAER) were measured, and the kidneys were collected to determine the production of reactive oxygen species (ROS) and assess renal pathologies. Immunohistochemistry and Western blot were employed to determine the protein levels of endothelial nitric oxide synthesis (eNOS) and phosphorylated AMP-activated protein kinase (pAMPK).

RESULTSUAER and ROS production increased significantly in DM group as compared with that in the control group (P<0.05), while no significant differences were found in UARE among the DM, DA, and DP groups (P>0.05). Blood glucose level, HbA1c and ROS were significantly decreased in DA group in comparison with those in DM group (P<0.05). Glomerular hypetrophy, mesangial expansion, basal membrane thickening, tubular epithelial cells cavitation and exfoliation, and mononuclear lymphocyte infiltration occurred in DM group, while these changes were ameliorated in gAd transfection group. The renal expression levels of eNOS and p-AMPK proteins in DM group were significantly lower than those in the control group (P<0.05) and gAd transfection group (P<0.05).

CONCLUSIONSThe renoprotective effect of adiponectin may be at least partially mediated by the activation of the AMPK signaling passway, ROS production inhibition, relief of the oxidative stress, and up-regulation of eNOS expression in the renal tissue of diabetic rats.

Adiponectin ; biosynthesis ; genetics ; pharmacology ; Animals ; Antioxidants ; pharmacology ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; Diabetic Nephropathies ; metabolism ; prevention & control ; Male ; Nitric Oxide Synthase Type III ; metabolism ; Oxidative Stress ; drug effects ; Protective Agents ; metabolism ; Random Allocation ; Rats ; Rats, Wistar ; Reactive Oxygen Species ; metabolism ; Transfection

OBJECTIVE: To compare the effect of intermittent and constant high glucose media on the synthesis of vascular relaxing factor nitric oxide (NO) in cultured human umbilical vein endothelial cells (HUVECs), and to investigate its mechanism. METHODS: HUVECs were exposed to 5.5 mmol/L glucose (normal control), 20 mmol/L glucose (constant high glucose), and 5.5 mmol/L alternating with 20 mmol/L glucose (intermittent high glucose) for 7 days. The NO level was measured using Griess Reaction in cell culture supernatants; the expressions of PI3K, PKB and eNOS mRNA and protein were measured with RT-PCR or Western blot. RESULTS: NO level in the intermittent high glucose group was significantly lower than that in the constant high glucose group (P<0.05). The expression of PI3K, PKB, and eNOS in the intermittent high glucose group was significantly lower than that in the constant high glucose group (P<0.05). CONCLUSION Intermittent high glucose could be more deleterious to endothelial cells than constant high glucose, and may lead to decrease synthesis of NO by inhibiting PI3K/PKB/eNOS pathway activation.
Cells, Cultured ; Culture Media ; Endothelial Cells ; cytology ; metabolism ; Glucose ; pharmacology ; Humans ; Nitric Oxide ; biosynthesis ; Nitric Oxide Synthase Type III ; genetics ; metabolism ; Phosphatidylinositol 3-Kinases ; genetics ; metabolism ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Umbilical Veins ; cytology

OBJECTIVETo investigate the changes in angiotensinogen (AGT), angiotensin II type 1 receptor (AT(1)R), endothelial nitric oxide synthase (eNOS) mRNA and protein expressions and nitric oxide (NO) content in the rat glomeruli in response to leptin stimulation.

METHODSThe glomeruli isolated from male SD rats were stimulated with 3 nmol/L leptin for 2 h. Real-time PCR and Western blotting were performed to analyze the mRNA and protein expressions of AGT, AT(1)R and eNOS in the glomeruli, and nitrite concentration in the glomeruli was measured by nitrate reductase assay.

RESULTSIn comparison with the control group, exposure to leptin increased the mRNA levels of AGT, ATR(1) and eNOS in the isolated glomeruli by 2.69-/+0.17, 3.77-/+0.16 and 2.56-/+0.29 folds (P=0.024, 0.018 and 0.044), and their protein levels by 2.06-/+0.10, 2.67-/+0.08 and 1.61-/+0.13 folds (P=0.021, 0.015 and 0.032), respectively. The NO production in the glomeruli was also increased by 2.77-/+0.14 folds (P=0.000) following leptin exposure.

CONCLUSIONLeptin exposure of isolated rat glomeruli directly causes activation of the internal renal renin-angiotensin system and enhanced NO production, suggesting that leptin plays a role in the pathogenesis of maladaptation in renal hemodynamics in obesity.

Animals ; Gene Expression Regulation ; drug effects ; Kidney Glomerulus ; drug effects ; metabolism ; Leptin ; pharmacology ; Male ; Nitric Oxide ; biosynthesis ; Nitric Oxide Synthase Type III ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptor, Angiotensin, Type 1 ; genetics ; metabolism ; Renin-Angiotensin System ; drug effects

OBJECTIVETo evaluate the effect of clearance of superoxide anion by catechin on the expression of nitrogen monoxidum (NO) and endothelial nitricoxide synthase (eNOS) and apoptosis in endothelial progenitor cells (EPCs) induced by angiotensin II (Ang II).

METHODSThe marrow endothelial progenitor cells of Sprague-Dawley rats were isolated and assigned to control (no treatment), Ang II treatment and Ang II + catechin treatment groups. After 48 hrs of culture, the concentration of O2*- in the supernate was measured by the NBT method, and NO concentration in the supernate was measured by the nitrate reductase method; the apoptosis rate of EPCs was detected by the TUNEL method; the mRNA expression of eNOS was detected by RT-PCR; the protein expression of eNOS was detected by Western blot analysis.

RESULTSAng II of 10-6 mol/L was determined as the suitable concentration for cell induction by the MTT test. Catechin of 400 mg/L was determined as an advisable intervention dosage. The apoptosis rate of EPCs in the control, the Ang II and the Ang II+catechin treatment groups were 2.48+/-0.12%, 54.18+/-0.77% and 16.87+/-0.35%, respectively, and there were significant differences among the three groups (P<0.01). The O2*- concentration in the Ang II and the Ang II+catechin treatment groups (81.7+/- 3.6 and 62.3+/- 2.2 U/L respectively) was significantly higher than that in the control group (33.7+/- 2.8 U/L) (P<0.01). An increased NO concentration was also found in the Ang II (189. 8+/- 9.0 micromol/L) and the Ang II+catechin treatment groups (276.4+/- 10.1 micromol/L) compared with that in the control group (105.8+/- 9.8 micromol/L) (P<0.01). There were significant differences in the concentrations of O2*- and NO between the Ang II and the Ang II+catechin treatment groups (P<0.05). The mRNA (P<0.05) and protein expression (P<0.01) of eNOS in the Ang II and the Ang II+catechin treatment groups increased significantly compared with those in the control group. The Ang II+catechin treatment group showed increased eNOS protein expression compared with the Ang II group (P<0.05).

CONCLUSIONSAng II may induce the generation of O2*-, inactivate NO and increase gene and protein expression of eNOS in EPCs. Catechin might decrease the apoptosis of EPCs through the effective clearance of O2*-and the reduction of NO inactivation and of eNOS protein uncoupling.

Angiotensin II ; pharmacology ; Animals ; Apoptosis ; drug effects ; Catechin ; pharmacology ; Cell Survival ; drug effects ; Endothelial Cells ; drug effects ; metabolism ; Female ; Nitric Oxide ; biosynthesis ; Nitric Oxide Synthase Type III ; analysis ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Stem Cells ; drug effects ; metabolism ; Superoxides ; metabolism