Angiotensin II Type 1 Receptor Blockers ; administration & dosage ; Animals ; Coronary Angiography ; Coronary Restenosis ; prevention & control ; Coronary Vessels ; pathology ; Drug Delivery Systems ; Immunohistochemistry ; Rabbits ; Receptor, Angiotensin, Type 1 ; analysis ; Receptor, Angiotensin, Type 2 ; analysis ; genetics ; physiology ; Reverse Transcriptase Polymerase Chain Reaction ; Stents ; Tetrazoles ; administration & dosage ; Valine ; administration & dosage ; analogs & derivatives ; Valsartan

Angiotensin II Type 1 Receptor Blockers ; administration & dosage ; therapeutic use ; Angiotensin-Converting Enzyme Inhibitors ; administration & dosage ; therapeutic use ; Chronic Disease ; Drug Therapy, Combination ; Humans ; Hypertension ; drug therapy ; Kidney Diseases ; drug therapy ; Proteinuria ; drug therapy

To increase the dissolution rate and extent of valsartan, valsartan nanosuspensions have been prepared. Controlled precipitation assisted with sonication is utilized to prepare valsartan nanosuspensions, the concentration of the drug, stabilizer and costablizer had a great effect on the stability of the preparation according to the pre-experiment. So the method of central composite design-response surface is used to optimize the prescription based on the above three factors and the particle size as the response value. The software Origin 8.0 is used to draw the view of the three-dimensional effects and 2D contour map, to get the optimal prescription area. Valsartan nanosuspensions were prepared. The mean diameter and zeta potential are about 216.6 nm and -57.7 mV, respectively. Compared with the microsuspensions and commercial preparation, the dissolution of valsartan nanosuspensions was faster and the bioavailability can be enhanced to some extent.
Angiotensin II Type 1 Receptor Blockers ; administration & dosage ; chemistry ; Biological Availability ; Chemical Precipitation ; Drug Stability ; Nanoparticles ; administration & dosage ; chemistry ; ultrastructure ; Particle Size ; Research Design ; Solubility ; Suspensions ; Ultrasonics ; methods ; Valsartan ; administration & dosage ; chemistry

OBJECTIVETo investigate the effect of angiotensin (Ang)II and its Janns-activated kinase-2 (JAK2) signal pathway in transdifferentiation of renal tubular cells under the challenge of acute ischemic reperfusion injury.

METHODSModels of acute ischemic reperfusion injury were established and the level of local AngII, a key element of renin-angiotensin system (RAS), in kidney was measured using radioimmunity technique. The expression of alpha-smooth muscle actin (alpha-SMA), a phenotype of mesenchymal cells, was detected by RT-PCR and immunohistochemistry methods. Renal tubule cells (NRK-52E) were cultured with various concentration of AngII, followed by blocking of PD123319, AngII receptor 2 antagonist, and AG490, an inhibitor of JAK2 signal pathway.

RESULTSAngII of kidney tissue increased immediately after acute ischemic-reperfusion injury, in time dependent fashion. Expression of alpha-SMA in renal tubule cells was found at 48 hours after ischemic-reperfusion injury and in NRK-52E cells treated by high concentration of AngII and was dose and time dependent. The peak of alpha-SMA expression was seen after 30 minute treatment at the dose of 10(-9) mol/L, which was interrupted by both of PD123319 and AG490.

CONCLUSIONSTransdifferentiation of renal tubular epithelial cells occurs under acute ischemic-reperfusion injury. Local renin-angiotensin system may play a role in the transdifferentiation of TEC through AT2 receptor and its JAK2 signal pathway.

Actins ; genetics ; metabolism ; Angiotensin II ; administration & dosage ; metabolism ; pharmacology ; Angiotensin II Type 1 Receptor Blockers ; pharmacology ; Animals ; Cell Differentiation ; drug effects ; Cell Line ; Dose-Response Relationship, Drug ; Imidazoles ; pharmacology ; Janus Kinase 2 ; antagonists & inhibitors ; Kidney Tubules ; cytology ; metabolism ; Male ; Pyridines ; pharmacology ; RNA, Messenger ; metabolism ; Rats ; Rats, Wistar ; Renin-Angiotensin System ; Reperfusion Injury ; metabolism ; pathology ; Signal Transduction ; drug effects ; Tyrphostins ; pharmacology

BACKGROUNDThe results from the ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET) indicated that the angiotensin-receptor blocker telmisartan was not inferior to the angiotensin-converting-enzyme inhibitor ramipril in reducing the composite endpoint of cardiovascular death, myocardial infarction, stroke or hospitalization for congestive heart failure in high-risk patients, and telmisartan was associated with slightly superior tolerability. The combination of the two drugs was associated with more adverse events without an increase in benefit. This study aimed to analyze the data from ONTARGET obtained from a subgroup of patients enrolled in China and to evaluate the demographic and baseline characteristics, the compliance, efficacy, and safety of the different treatment strategies in randomized patients in China.

METHODSA total of 1159 high-risk patients were randomized into three treatment groups: with 390 assigned to receive 80 mg of telmisartan, 385 assigned to receive 10 mg of ramipril and 384 assigned to receive both study medications. The median follow-up period was 4.3 years.

RESULTSThe mean age of Chinese patients was 65.6 years, 73.6% of patients were male. The proportion of patients with stroke/transient ischemic attacks at baseline in China was two times more than the entire study population (47.7% vs. 20.9%). In Chinese patients the proportion of permanent discontinuation of study medication due to cough was 0.5% in the telmisartan group, which was much less than that in the combination or the ramipril group. There were no significant differences in the incidence of primary outcome among three treatment groups of Chinese patients. More strokes occurred in Chinese patients than in the entire study population (8.5% vs. 4.5%). Greater systolic blood pressure reduction (-9.8 mmHg), and more renal function failure were noted in the combination treatment group than in the ramipril or telmisartan group (2.6% vs. 1.6% and 1.0%).

CONCLUSIONSThere was no evidence that the results of ONTARGET differed between Chinese patients and the entire study population with respect to the incidence of primary outcome, particularly safety. Compliance with study medications was good. The evidence from ONTARGET indicated that the treatment strategies in ONTARGET were applicable to patients in China.

Aged ; Angiotensin II Type 1 Receptor Blockers ; therapeutic use ; Angiotensin-Converting Enzyme Inhibitors ; therapeutic use ; Benzimidazoles ; administration & dosage ; adverse effects ; therapeutic use ; Benzoates ; administration & dosage ; adverse effects ; therapeutic use ; China ; Drug Therapy, Combination ; Female ; Heart Failure ; drug therapy ; Humans ; Male ; Middle Aged ; Ramipril ; administration & dosage ; adverse effects ; therapeutic use

OBJECTIVETo investigate the origin of oxidative stress induced by angiotensin II (AngII) in human mesangial cells and the role of reactive oxygen species (ROS) in AngII-induced monocyte chemoattractant protein-1 (MCP-1) expression.

METHODSMCP-1 expression was determined by real time RT-PCR. ROS production was measured by DCFDA fluorescence. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity was examined by lucigenin chemiluminescence. p47phox and p67phox translocation was assayed by Western blot. Twenty-four male mice were randomly divided into three groups: the control, the AngIIinfusion [AngII 400 ng/(kg.min)], and the apocynin treatment. AngII was infused by subcutaneously osmotic minipump for 14 days. Urinary albumin and 8-isoprostane excretion were measured by ELISA.

RESULTSIn cultured human mesangial cells, AngII induced the MCP-1 expression in a dose-dependent manner with 3.56 fold increase as compared with the control. AngII increased intracellular ROS production as early as 3 min with the peak at 60 min and was in a time and dose-dependent. Incubation with different dosages of AngII (1 nmol/L, 10 nmol/L, and 100 nmol/L AngII) for 60 min, ROS production increased at 1.82, 2.92, and 4.08 folds respectively. AngII-induced ROS generation was sensitive to diphenyleneiodonium sulfate (DPI, 10 micromol/L) and apocynin (500 micromol/L), two structurally distinct NADPH oxidase inhibitors. In contrast, inhibitors of other oxidant-producing enzymes, including the mitochondrial complex Iinhibitor rotenone, the xanthine oxidase inhibitor allopurinol, the cyclooxygenase inhibitor indomethacin, the lipoxygenase inhibitor nordihydroguiaretic acid, the cytochrome P450 oxygenase inhibitor ketoconazole and the nitric oxide synthase inhibitor G-nitro-L-arginine methyl ester were without an effect. AngII-induced ROS generation was inhibited by the AT1 antagonist losartan (10 micromol/L) but not the AT2 antagonist PD123319 (10 micromol/L). AngII treatment induced translocation of cytosolic of p47phox and p67phox to the membrane. The antioxidants almost abolished AngII-induced MCP-1 expression. AngII infusion increased urinary and p67 translocation by 2.69-, 2.97-, and 2.67-fold, respectively.

CONCLUSIONSNADPH oxidase-derived ROS is involved in AngII-induced MCP-1 expression. Inhibition of NADPH oxidase alleviates AngII-induced renal injury.

Acetophenones ; pharmacology ; Angiotensin II ; administration & dosage ; pharmacology ; Angiotensin II Type 1 Receptor Blockers ; pharmacology ; Animals ; Cells, Cultured ; Chemokine CCL2 ; metabolism ; Dose-Response Relationship, Drug ; Humans ; Losartan ; pharmacology ; Male ; Mesangial Cells ; metabolism ; Mice ; Mice, Inbred C57BL ; NADPH Oxidases ; antagonists & inhibitors ; metabolism ; Onium Compounds ; pharmacology ; Oxidative Stress ; Phosphoproteins ; metabolism ; Protein Transport ; Random Allocation ; Reactive Oxygen Species ; metabolism

The study aims to evaluate the bioequivalence of valsartan hydrochlorothiazide tablets, and to investigate the potential cause of bioinequivalence. This was a single-center study with an open, randomized double-way crossover design. Test and reference preparations containing 160 mg of valsartan and 25 mg of hydrochlorothiazide were given to 36 healthy male volunteers. Plasma concentrations of valsartan and hydrochlorothiazide were determined simultaneously by LC-MS/MS. The pharmacokinetic parameters and relative bioavailability were calculated, while the bioequivalence between test and reference preparations were evaluated. The dissolution profiles of test and reference preparations in four different mediums were determined via dissolution test and HPLC. The similarity was investigated according to the similarity factors (f2). The F(o-t) and F(0-infinity) were (139.4 +/- 65.2)% and (137.5 +/- 61.2)% for valsartan of test preparations. It led to get the conclusion that test and reference preparations were not bioequivalent for valsartan. A significant difference was observed between test and reference tablets in the valsartan dissolution test of pH 1.2 hydrochloric acid solution. The key factor of the bioinequivalence might be that dissolution of valsartan in acid medium has marked difference between two preparations.
Administration, Oral ; Adolescent ; Adult ; Angiotensin II Type 1 Receptor Blockers ; administration & dosage ; adverse effects ; blood ; pharmacokinetics ; Antihypertensive Agents ; administration & dosage ; adverse effects ; blood ; pharmacokinetics ; Area Under Curve ; Chromatography, Liquid ; Cross-Over Studies ; Drug Liberation ; Humans ; Hydrochlorothiazide ; administration & dosage ; adverse effects ; blood ; pharmacokinetics ; Male ; Tablets ; Tandem Mass Spectrometry ; Therapeutic Equivalency ; Valsartan ; administration & dosage ; adverse effects ; blood ; pharmacokinetics ; Young Adult

BACKGROUNDTransforming growth factor (TGF) beta(1)-Smads signal plays an important role in cardiac remodeling following myocardial infarction (MI). In addition, both angiotensin converting enzyme inhibitor (ACEI) and angiotensin II type I receptor blocker (ARB) can effectively prevent left ventricular remodeling. The current study focused on whether the combination of ACEI and ARB is more beneficial for preventing ventricular remodeling and whether Smad proteins mediate this beneficial effect.

METHODSMI was induced by ligating the left anterior descending coronary artery in rats. Twenty-four hours after ligation, the survived rats were randomly divided into five groups and treated for 8 weeks: placebo group, ACEI group (benazepril 10 mg.kg(-1).d(-1)), ARB group (irbesartan 50 mg.kg(-1).d(-1)), ACEI + ARB group (benazepril 10 mg.kg(-1).d(-1) + irbesartan 50 mg.kg(-1).d(-1)) and control group (sham-operated rats). After 8 weeks, we examined the following indexes: the ratio of ventricular weight to body weight (VW/BW), left ventricular end diastolic dimension (LVDd), ejection fraction (EF), fractional shortening (FS), ratio of E-wave to A-wave velocity, collagen of noninfarcted zone, the mRNA expression of TGFbeta(1), Smad 2, and Smad 3 by RT-PCR in noninfarcted zone, the protein expression of Smad 2 and Smad 3 in noninfarcted zone by Western blot.

RESULTSVW/BW significantly increased in the placebo groups compared with that in the control group (P < 0.01). This increase was limited in ACEI, ARB, and combined groups (P < 0.01 compared with placebo group). There was no significant difference among the three actively treated groups. Collagen was increased in placebo group (5.68 +/- 0.5)% compared with that in control group (P < 0.01). ACEI, ARB and combined treatment attenuated this increase of collagen [(4.3 +/- 0.5)%, (3.5 +/- 0.5)%, (3.2 +/- 0.4)%] in comparison with that in placebo group (P < 0.01 respectively). Combined treatment showed more significant effect on collagen deposition. EF and FS significantly decreased, LVDd and E/A significantly increased in placebo group compared with that in control group (P < 0.01 respectively). ACEI, ARB and combined treatment ameliorated these indexes (P < 0.01 compared with placebo group). The mRNA expression of TGFbeta(1), Smad 2, and Smad 3 (0.700 +/- 0.045, 0.959 +/- 0.037 and 0.850 +/- 0.051) increased in placebo group compared with that in control group (P < 0.01). ACEI, ARB and combined treatment normalized the increase (P < 0.01). Furthermore, ARB and combined treatment proved to be more effective in decreasing TGF beta(1) and Smad mRNA expression than ACEI treatment (P < 0.01). The expression of Smad 2 and Smad 3 protein increased in placebo group compared with that in control group (P < 0.01). ACEI, ARB and combined treatment normalized the increase (P < 0.01). Furthermore, ARB and combined treatment proved to be more effective than ACEI alone (P < 0.01).

CONCLUSIONSTGFbeta(1)-Smads signal activation is correlated with ventricular remodeling following MI. ACEI and ARB treatment prevents ventricular remodeling by inhibiting expression of Smad 2 and Smad 3. ARB and combined treatment are more effective than ACEI alone.

Angiotensin II Type 1 Receptor Blockers ; administration & dosage ; therapeutic use ; Angiotensin-Converting Enzyme Inhibitors ; administration & dosage ; therapeutic use ; Animals ; Drug Therapy, Combination ; Echocardiography ; Male ; Myocardial Infarction ; drug therapy ; Rats ; Rats, Wistar ; Smad2 Protein ; analysis ; genetics ; Smad3 Protein ; analysis ; genetics ; Transforming Growth Factor beta ; genetics ; Transforming Growth Factor beta1 ; Ventricular Remodeling ; drug effects

The effects of the combined use of angiotensin converting enzyme inhibitor (ACEI) benazepril and angiotensin II type 1 receptor antagonist (AT1RA) valsartan on apoptosis and the expression of apoptosis-related proteins Fas and FasL in the kidney of rats with adriamycin-induced nephritic glomerulosclerosis was investigated. Uninephrectomy and the injection of adriamycin induced the rat model of glomerulosclerosis. Benazepril (6 mg/kg), valsantan (20 mg/kg), or benazepril (3 mg/kg) plus valsantan (20 mg/kg) was respectively delivered daily by gavage to the rats in three treatment groups for 12 weeks. Apoptosis was examined by means of terminal-deoxynucleotidyl transferase mediated d-UTP nick end labeling (TUNEL). Immunohistochemistry was adopted to detect the expression of Fas and FasL. Software of pathological analysis quantitated the levels of Fas and FasL. The results showed that as compared with those in the control group, the kidneys in the model group had more severe glomerulosclerosis, much more apoptotic cells and higher levels of expression of Fas and FasL. The degree of glomerulosclerosis, the number of apoptotic cells and the levels of expression of Fas and FasL were reduced by benazepril and valsartan. The combined use of benazepril and valsartan had the best therapeutic effect. It was concluded that benazepril and valsartan could suppress the excessive apoptosis of kidney cells by lowering the expression of the apoptosis-related proteins Fas and FasL, so as to postpone the process of glomerulosclerosis. The combined use of benazepril and valsartan has better therapeutic effect.
Angiotensin II Type 1 Receptor Blockers ; administration & dosage ; Angiotensin-Converting Enzyme Inhibitors ; administration & dosage ; Animals ; Apoptosis ; drug effects ; Benzazepines ; administration & dosage ; Doxorubicin ; Drug Therapy, Combination ; Fas Ligand Protein ; Glomerulosclerosis, Focal Segmental ; chemically induced ; drug therapy ; pathology ; Kidney ; pathology ; Male ; Membrane Glycoproteins ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Tetrazoles ; administration & dosage ; Tumor Necrosis Factors ; biosynthesis ; genetics ; Valine ; administration & dosage ; analogs & derivatives ; Valsartan ; fas Receptor ; biosynthesis ; genetics

BACKGROUNDS AND AIMS: Angiotensin receptors are found on hepatic stellate cells, which participate in hepatic fibrosis. Therefore, it is presumed that angiotensin has a role in hepatic fibrosis. The aim of this study was to evaluate the effects of angiotensin blockade on inhibition of hepatic fibrosis in cirrhotic rat model. Material and METHODS: Cirrhosis with portal hypertension was produced by common bile duct ligation (BDL) in the adult Sprague-Dawley rats. They were classified into 4 groups (each group n=6) as follows; G1: BDL without drug, G2: BDL+captopril 100 mg/kg/day beginning 2 weeks after BDL, G3: BDL+captopril 100 mg/kg/day, starting just after BDL, G4: BDL+losartan 10 mg/kg/day, starting just after BDL. After 4 weeks following BDL, hepatic fibrosis was histomorphologically analyzed by Batts & Ludwig score. Alpha smooth muscle actin by immunohistochemical stain, hydroxyproline contents of liver tissue by spectrophotometry and expression of collagen, procollagen, and TGF-beta by real-time PCR were measured. RESULTS: Batts & Ludwig score were 3.8, 3.0, 2.6,and 2.6 in G1, G2, G3, and G4, respectively. The expression of alpha-SMA was significantly lower in G3 and G4 than in G1; 11.9%, 10.9%, 2.6%, and 1.1% in G1, G2, G3, and G4, respectively (p<0.05). The concentration of hydroxyproline (microgram/g liver tissue) was lower in G3 and G4 compared with G1 (p<0.05). Also, the administration of angiotensin blockade just after BDL significantly reduced the expression of collagen, procollagen, and TGF-beta mRNA. CONCLUSIONS: Angiotensin blockades are effective in the prevention of hepatic fibrosis in BDL rats.
Actins/metabolism ; Angiotensin II Type 1 Receptor Blockers/administration & dosage/*therapeutic use ; Animals ; Bile Ducts/pathology/surgery ; Captopril/administration & dosage/*therapeutic use ; Fibrosis ; Hydroxyproline/metabolism ; Ligation ; Liver/drug effects/metabolism/pathology ; Liver Cirrhosis, Experimental/*drug therapy/etiology/metabolism ; Losartan/administration & dosage/*therapeutic use ; Male ; Rats ; Rats, Sprague-Dawley ; Transforming Growth Factor beta/metabolism