OBJECTIVETo explore the effects of valsartan and MEK1/2 inhibitor U0126 on atrial fibrosis and connexin40 (Cx40) remodeling in rats treated with isoproterenol (ISO).

METHODS32 male SD rats were randomly divided into control group (A), ISO (5 mg · kg(-1) · d(-1) for 7 days) + DMSO group (B), ISO + U0126 (0.5 mg · kg(-1) · d(-1) for 28 days) group (C, U0126 was dissolved in DMSO), ISO + valsartan (30 mg · kg(-1) · d(-1) for 28 days) + DMSO group (D). Rats were sacrificed after 28 days. The AngIIcontent in myocardial tissue was measured by radioimmunoassay, P-MEK1/2, P-ERK1/2 and Cx40 was detected by immunohistochemistry, atrial fibrosis was determined on HE and Masson stained heart sections.

RESULTSThe content of AngII was significantly higher in group B, C and D compared with group A [(368.243 ± 6.283) ng/L, (357.175 ± 5.944) ng/L, (359.908 ± 2.496) ng/L vs (250.380 ± 4.261) ng/L, P < 0.01]; the degree of atrial fibrosis was significantly lower in group C and D compared with group B [CVF(10.260 ± 0.525)%, (10.238 ± 0.524)% vs (78.710 ± 1.587)%, P < 0.01] while there was no atrial fibrosis in group A [CVF(9.025 ± 0.456)%]; the expression of P-MEK1/2 and P-ERK1/2 was significantly upregulated in group B compared with group A (P-MEK1/2: 0.311 ± 0.007 vs 0.203 ± 0.009, P < 0.01; P-ERK1/2: 0.259 ± 0.003 vs 0.173 ± 0.006, P < 0.01) and significantly lower in group C and D compared with group B (P-MEK1/2: 0.212 ± 0.004, 0.213 ± 0.005 vs 0.311 ± 0.007, P < 0.01, P-ERK1/2: 0.178 ± 0.004, 0.175 ± 0.007 vs 0.259 ± 0.003, P < 0.01). The content of Cx40 was obviously reduced and the distribution of Cx40 was disordered in group B compared with A (0.199 ± 0.007 vs 0.241 ± 0.004, P < 0.01) which could be partly reversed in group C and D (0.239 ± 0.037, 0.235 ± 0.006 vs 0.199 ± 0.007, P < 0.01). All parameters in group C and D were similar (P > 0.05).

CONCLUSIONThe chronically elevated AngII content in myocardium may be related to atrial fibrosis and Cx40 remodeling in this model, valsartan and U0126 were equivalent on attenuating atrial fibrosis and Cx40 remodeling by inhibiting ERK pathways at different levels.

Animals ; Butadienes ; pharmacology ; Connexins ; metabolism ; Fibrosis ; Heart Atria ; metabolism ; pathology ; Male ; Myocardium ; metabolism ; pathology ; Nitriles ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Tetrazoles ; pharmacology ; Valine ; analogs & derivatives ; pharmacology ; Valsartan

Angiotensin II Type 1 Receptor Blockers ; pharmacology ; Animals ; Cell Proliferation ; drug effects ; Cells, Cultured ; Collagen Type I ; biosynthesis ; Hepatocytes ; cytology ; metabolism ; Tetrazoles ; pharmacology ; Valine ; analogs & derivatives ; pharmacology ; Valsartan

OBJECTIVETo explore the pathogenic changes of myocardial apoptosis in heart hypertrophy during hypertension and evaluate the anti-apoptosis effect of Valsartan.

METHODSThirty spontaneously hypertensive rats (SHRs) were divided into two groups: 15 treated with Valsartan (20 mg x kg(-1) x d(-1)) (SHR + Valsartan group), the others with placebo (SHR + placebo group), with 15 normal Wistar rats as control. Systolic blood pressure was measured by the tail-cuff method. The observation period was from 8 to 16 weeks of age. Cardiac apoptosis was evaluated by a Terminal Deoxynucleotidyl Transferase-Mediated dUTP-biotin Nick End Labeling (TUNEL) assay.

RESULTSMean blood pressure values were 127 +/- 2 mm Hg in controls, 163 +/- 6 mm Hg in the SHR + Valsartan group and 193 +/- 7 mm Hg in the SHR + placebo group at 16 weeks of age, whereas the blood pressure in 8-week-old SHR and Wistar rats were 175 +/- 3 mm Hg and 125 +/- 5 mm Hg, respectively. The ratio of the heart weight over body weight declined in Wistar (3.07 +/- 0.03 mg/g) and SHR + Valsartan groups (3.22 +/- 0.19 mg/g) compared with the SHR + placebo group (4.02 +/- 0.31 mg/g) (P < 0.05). The density of TUNEL-positive cells in Wistar and SHR +/- Valsartan groups was 23.3 +/- 3.3 nuclei/HPF and 35.0 +/- 1.3 nuclei/HPF, both of which were significantly less than that of the SHR + placebo group (116.7 +/- 11.3 nuclei/HPF).

CONCLUSIONSIn response to chronic pressure overload, cardiomyocyte-specific apoptosis contributes to the transition from compensatory hypertrophy to decompensation. Apoptosis may be effectively inhibited by Valsartan in the early stage of hypertension.

Animals ; Antihypertensive Agents ; pharmacology ; Apoptosis ; drug effects ; Cardiomegaly ; pathology ; Hypertension ; pathology ; Myocardium ; cytology ; Rats ; Rats, Inbred SHR ; Rats, Wistar ; Tetrazoles ; pharmacology ; Valine ; analogs & derivatives ; pharmacology ; Valsartan

OBJECTIVETo investigate the effects of valsartan on cyclooxygenase-2 (COX-2) in cultured human umbilical vein endothelial cells (HUVECs) stimulated by ox-LDL.

METHODSHUVECs were cultured in endothelial basal medium and divided into four groups (n = 5 each): group I, control group without any treatment; group II: HUVECs stimulated with ox-LDL (100 mg/L) in endothelial basal medium for 24 hours; group III: HUVECs treated with ox-LDL (100 mg/L) and valsartan (10 µmol/L) in endothelial basal medium for 24 hours; group IV: HUVECs treated with ox-LDL (100 mg/L) and valsartan (30 µmol/L) in endothelial basal medium for 24 hours. Expression of COX-1 and COX-2 mRNA were determined by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTSExpression of and COX-2 mRNA was significantly higher in ox-LDL-treated HUVECs than in control group (1.478 ± 0.104 vs. 0.366 ± 0.104, P < 0.05), while expression of COX-1 mRNA was similar between the 2 groups (P > 0.05). Valsartan dose-dependently decreased the COX-2 mRNA expression (group III vs. group II: 1.074 ± 0.112 vs. 1.478 ± 0.104, P < 0.05; group IV vs. group II: 0.664 ± 0.104 vs. 1.478 ± 0.104, P < 0.05). Expression of COX-1 mRNA in ox-LDL-treated HUVECs was not affected by valsartan.

CONCLUSIONSCOX-2 mRNA expression in ox-LDL-treated HUVECs could be reduced by valsartan suggesting valsartan might attenuate atherosclerosis by reducing ox-LDL-induced inflammatory responses.

Cells, Cultured ; Cyclooxygenase 2 ; metabolism ; Human Umbilical Vein Endothelial Cells ; drug effects ; metabolism ; Humans ; Lipoproteins, LDL ; adverse effects ; Tetrazoles ; pharmacology ; Valine ; analogs & derivatives ; pharmacology ; Valsartan

High performance liquid chromatography-time-off-flight mass spectrometer (HPLC-TOFMS) technology coupled with partial least squares discriminant analysis (PLS-DA) processed by SIMCA-P software was applied to investigate serum endogenous metabolites alternations of valsartan in spontaneous hypertension rats (SHR). And MetPA platform was used to connect identified potential biomarkers in corresponding metabolic pathways to find possible therapeutic mechanism of valsartan. Valsartan significantly declined the blood pressure of SHRs (P < 0.05) at fourth week. The metabolic profiling significantly changed and four metabolites involved in G protein-coupled pathway were identified. Metabolomics is able to detect holistic and microcosmic alternations in organism, so as to elucidate therapeutic mechanism of drugs.
Animals ; Biomarkers ; blood ; Blood Pressure ; Chromatography, High Pressure Liquid ; Discriminant Analysis ; Least-Squares Analysis ; Mass Spectrometry ; Metabolome ; Metabolomics ; Rats ; Rats, Inbred SHR ; Valsartan ; pharmacology

BACKGROUNDVascular smooth muscle cell proliferation is an important process in the development of atherosclerosis and is associated with other cellular processes in atherogenesis. Telmisartan is reported to have partial peroxisome proliferator-activated receptor (PPAR)-γ activating properties and has been referred to as selective PPAR modulators, but valsartan just blocks angiotensin II (AngII) type 1 (AT1) receptors. This study aimed to compare the different effects of telmisartan and valsartan on human aortic smooth muscle cells (HASMCs) proliferation.

METHODSAbility of telmisartan and valsartan to inhibit proliferation of HASMCs was evaluated by the Cell Counting Kit-8 (CCK-8) in continuous cell culture. Whether the antiproliferative effects of telmisartan and valsartan depend on their effects on AngII receptors or activating the peroxisome PPAR-γ was also investigated in this study.

RESULTSTelmisartan inhibited proliferation of HASMCs by 52.4% (P < 0.01) at the concentration of 25 µmol/L and the effect depended on the dose of telmisartan, but valsartan had little effect on HASMCs proliferation (P > 0.05) and no dose response. When tested in cells stimulated with AngII, telmisartan had the same inhibition of HASMCs by 59.2% (P < 0.05) and valsartan also inhibited it by 41.6% (P < 0.05). Telmisartan and valsartan had the same effect on down-regulating AT1 receptor expression and telmisartan was superior to valsartan up-regulating AngII type 2 (AT2) receptor expression. Antiproliferative effects of telmisartan were observed when HASMCs were treated with the PPAR-γ antagonist GW9662 but antiproliferative effects of the PPAR-γ activator pioglitazone were not observed.

CONCLUSIONSTelmisartan, but not valsartan, inhibits HASMCs proliferation and has dose-dependent response without stimulation of AngII. AT2 receptor up-regulation of telmisartan contributes to its greater antiproliferative effects than valsartan. Its PPAR-γ activation does not play a critical role in inhibiting HASMCs proliferation.

Benzimidazoles ; pharmacology ; Benzoates ; pharmacology ; Cell Proliferation ; drug effects ; Humans ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Myocytes, Smooth Muscle ; cytology ; drug effects ; PPAR gamma ; metabolism ; Receptor, Angiotensin, Type 1 ; metabolism ; Receptor, Angiotensin, Type 2 ; metabolism ; Tetrazoles ; pharmacology ; Valine ; analogs & derivatives ; pharmacology ; Valsartan

OBJECTIVETo investigate the effects of ox-LDL, ACEI and ARB on expressions and activities of TF and TFPI in VSMC.

METHODS(1) Rabbit VSMC was cultured by explant-attached method in vitro. (2) The effects of ox-LDL and valsartan on TF and TFPI expressions were analyzed by immunohistochemistry and immunofluorescence. Laser scanning confocal microscopy were applied to analyze the effects of ox-LDL and valsartan on TF expression. The effects of ox-LDL, valsartan and captopril on TF and TFPI antigen expressions were analyzed by ELISA. Chromogenic substrate method was used to determine the effects of ox-LDL, valsartan and captopril on TF activity. The effects of ox-LDL and valsartan on TF mRNA expression were analyzed by RT-PCR.

RESULTS(1) ox-LDL could upregulate TF antigen, activity and TF expression at mRNA level and downregulate TFPI antigen. (2) Valsartan and captopril could reduce TF antigen and activity in VSMC treated by ox-LDL, and valsartan reduce it in a dose-dependent manner. Valsartan could also attenuate TF expression at mRNA level in VSMC treated by ox-LDL. (3) Using ELISA, valsartan and captopril could also enhance TFPI antigen in VSMC treated by ox-LDL.

CONCLUSIONOur study showed upregulated TF and downregulated TFPI expression and activity by ox-LDL and these effects could be reversed by ACEI and ARB indicating a new insight on the antiatherosclerotic effects of ACEI and ARB.

Animals ; Captopril ; pharmacology ; Cells, Cultured ; Endothelium, Vascular ; cytology ; metabolism ; Male ; Proton-Translocating ATPases ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; Rabbits ; Tetrazoles ; pharmacology ; Thromboplastin ; biosynthesis ; genetics ; Valine ; analogs & derivatives ; pharmacology ; Valsartan

The transmural heterogeneous changes of transient outward potassium currents (Ito) in rabbit hypertrophic cardiaomyocytes and the effects of long-term prophylactic treatment with volsartan were investigated. Rabbits were divided into hypertrophy group (left ventricular hypertrophy induced by partial ligation of abdominal aorta), vol-treated group (volsartan was administrated after the ligation), and control group (sham operated). Myocytes were isolated by a two-step enzymatical method. The sub-endocardial (Endo) and sub-epicardium (Epi) tissues were separated from midmyocardium (Mid) with a razor. Whole-cell patch-clamp technique was used to record potassium currents. The results showed that membrane capacitance was larger in hypertrophic cells than those in control and vol-treated cells (P<0.01 vs control cells, n=30). The densities of Ito in hypertrophic cells were reduced by sub-epicardium (Epi) (27.8 +/- 2.9) %, midmyocardium (Mid) (41.0+/-4.7) %, and sub-endocardium (Endo) (20.3 +/- 3.4) % compared with those in control cells. The decrease of Ito density was more pronounced in Mid than in Epi and Endo (P<0.01 vs Epi or Endo). There were no significant differences in Ito densities between vol-treated group and control group in three layers separately. In conclusion, volsartan can inhibit the transmural heterogeneous changes of Ito in left ventricular hypertrophic cardiomyocytes in rabbit.
Animals ; Antihypertensive Agents ; pharmacology ; Biological Transport, Active ; drug effects ; Female ; Hypertrophy, Left Ventricular ; drug therapy ; pathology ; Male ; Myocytes, Cardiac ; pathology ; Patch-Clamp Techniques ; Potassium Channels ; drug effects ; Rabbits ; Tetrazoles ; pharmacology ; Valine ; analogs & derivatives ; pharmacology ; Valsartan

OBJECTIVETo observe the effects of angiotensin II type 1 receptor blocker valsartan in preventing hepatic fibrosis induced by dimethylnitrosamine in rats.

METHODSExcept rats in the control group, all were given intraperitoneal injections of 1% dimethylnitrosamine (DMN 1 ml/kg, two or three consecutive days/a week for 6 weeks). From the first day of the intraperitoneal injection, rats in treatment groups were given valsartan for 8 weeks by gastric gavage. Liver tissue and blood samples of all rats were examined at 56 days (8 weeks). AngII levels were determined by radioimmunoassay. Hepatic mRNA levels of Collagen type I (Col I) and tissue inhibitor of metalloproteinase1 (TIMP1) were evaluated by reverse-transcription polymerase chain reaction (RT-PCR).

RESULTSValsartan significantly attenuated the degree of liver fibrosis and decreased the hepatic AngII content compared with DMN treated rats (P<0.01). mRNA levels of Col I and TIMP1 were upregulated in DMN treated rats compared with normal rats. Valsartan downregulated the elevation of Col I and TIMP1 mRNA levels (P<0.01).

CONCLUSIONHepatic AngII content of the model group was increased, the local tissue RAS was activated in DMN induced liver fibrosis. Valsartan can retard the progression of hepatic fibrosis and may provide an effective new strategy for anti-liver fibrosis therapy.

Angiotensin II Type 1 Receptor Blockers ; pharmacology ; therapeutic use ; Animals ; Dimethylnitrosamine ; Female ; Liver Cirrhosis, Experimental ; chemically induced ; prevention & control ; Male ; Random Allocation ; Rats ; Rats, Wistar ; Tetrazoles ; pharmacology ; therapeutic use ; Valine ; analogs & derivatives ; pharmacology ; therapeutic use ; Valsartan

OBJECTIVETo evaluate the effects of valsartan and carnitine on cardiomyocyte Calpain-1 and Bcl-xl expressions of dogs with chronic alcohol intake-induced cardiomyopathy.

METHODSDogs were randomly assigned into 4 groups (n = 7 each): (1) alcohol fed (free access to 5%, 1(st) week; 10% 2(nd) week; 500 ml 25% bolus plus free access to 5% from 3 to 24 weeks, A); (2) alcohol + valsartan (5 mg×kg(-1)×d(-1), B); (3) alcohol + carnitine (300 mg×kg(-1)×d(-1), C); (4) Control (D). After six months, all animals were assessed for left ventricular (LV) function by echocardiography. The Bad and Bcl-xl protein expressions were evaluated by immunohistochemistry. The expression of Calpain-1 protein was determined with Western blot. Myocardial morphology was quantified on HE stained slices and under electron microscopy. The terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) was performed for apoptosis analysis.

RESULTSCompared with group D, LVEDD and LVESD were significantly increased while EF and FS significantly decreased in group A. In alcohol fed group, expressions of Bad and Calpain-1 protein were significantly increased while Bcl-xl protein expression was downregulated, all changes could be significantly attenuated by intervention with valsartan and carnitine (all P < 0.05).

CONCLUSIONThese data suggest that alcohol could promote cardiac myocyte apoptosis, reduce cardiac function and aggravate myocardial remodeling which valsartan and carnitine could reduce alcoholic cardiomyopathy by downregulating Calpain-1 and Bad protein expression and upregulating expression of Bcl-xl protein.

Animals ; Apoptosis ; drug effects ; Calpain ; metabolism ; Cardiomyopathy, Alcoholic ; metabolism ; pathology ; Carnitine ; pharmacology ; Disease Models, Animal ; Dogs ; Myocytes, Cardiac ; drug effects ; metabolism ; Tetrazoles ; pharmacology ; Valine ; analogs & derivatives ; pharmacology ; Valsartan ; bcl-Associated Death Protein ; metabolism ; bcl-X Protein ; metabolism