enalapril and candesartan-cilexetil

Clinical trials of candesartan cilexetil conducted in Japan are reviewed. Candesartan cilexetil inhibited the pressor response to intravenous angiotensin II in healthy volunteers, with peak effects observed at 4 or 8 h after oral dosing; suppressing effects persisted up to 24 h. In 14 multicentre studies with 928 hypertensive patients treated for 8 to 12 weeks, candesartan cilexetil had an efficacy rate (reduction of systolic/diastolic blood pressure > or = 20/10 mm Hg and/or mean blood pressure > or = 13 mm Hg) of 72% and 63%, and an adverse effect rate of 9.9% and 7.3%, in patients with mild-to-moderate essential hypertension and those with impaired renal function, respectively. When data for elderly patients were analysed, there was no difference in efficacy and tolerability compared to non-elderly patients. In a double-blind comparative study, candesartan cilexetil was superior to enalapril in hypertensive patients: efficacy rate, 74% vs 66% (NS); adverse symptom rate, 10.4% vs 27.3% (P < 0.01); incidence of cough, 1.5% vs 14.8% (P < 0.01). Treatment with 2-8 mg of candesartan cilexetil once daily for 8 to 12 weeks reduced the left ventricular mass index without deterioration of cardiac function. In conclusion, 4-12 mg of candesartan cilexetil once daily is effective and well tolerated in patients with essential hypertension, including elderly patients, those with severe hypertension, and hypertensive patients with renal insufficiency. Its improved tolerability profile over angiotensin-converting enzyme inhibitors, as well as its end-organ protective effects, suggest that candesartan cilexetil is useful as a first-line antihypertensive drug.

Topics: Administration, Oral; Aged; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Circadian Rhythm; Enalapril; Follow-Up Studies; Humans; Hypertension; Japan; Randomized Controlled Trials as Topic; Retrospective Studies; Tetrazoles; Treatment Outcome

Topics: Age Factors; Aged; Angiotensin I; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Anti-Arrhythmia Agents; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Captopril; Clinical Trials as Topic; Death, Sudden, Cardiac; Enalapril; Heart Failure; Humans; Losartan; Prodrugs; Prognosis; Randomized Controlled Trials as Topic; Risk Factors; Tetrazoles; Time Factors

To compare the effects of candesartan cilexetil and enalapril maleate on right ventricular myocardial remodeling in dogs with experimentally induced pulmonary stenosis.. 24 Beagles.. 18 dogs underwent pulmonary arterial banding (PAB) to induce right ventricular pressure overload, and 6 healthy dogs underwent sham operations (thoracotomy only [sham-operated group]). Dogs that underwent PAB were allocated to receive 1 of 3 treatments (6 dogs/group): candesartan (1 mg/kg, PO, q 24 h [PABC group]), enalapril (0.5 mg/kg, PO, q 24 h [PABE group]), or no treatment (PABNT group). Administration of treatments was commenced the day prior to surgery; control dogs received no cardiac medications. Sixty days after surgery, right ventricular wall thickness was assessed echocardiographically and plasma renin activity, angiotensin-converting enzyme activity, and angiotensin I and II concentrations were assessed; all dogs were euthanatized, and collagenous fiber area, cardiomyocyte diameter, and tissue angiotensin-converting enzyme and chymase-like activities in the right ventricle were evaluated.. After 60 days of treatment, right ventricular wall thickness, cardiomyocyte diameter, and collagenous fiber area in the PABNT and PABE groups were significantly increased, compared with values in the PABC and sham-operated groups. Chymase-like activity was markedly greater in the PABE group than in other groups.. Results indicated that treatment with candesartan but not enalapril effectively prevented myocardial remodeling in dogs with experimentally induced subacute right ventricular pressure overload.

Topics: Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Constriction, Pathologic; Dog Diseases; Dogs; Enalapril; Heart Ventricles; Hypertrophy, Right Ventricular; Pulmonary Valve Stenosis; Tetrazoles; Ventricular Remodeling

To evaluate the effectiveness and safety of dual renin-angiotensin system (RAS) blockage together with total embryo cryopreservation for prevention of ovarian hyperstimulation syndrome (OHSS) in overstimulated patients undergoing IVF.. Retrospective case series.. A private tertiary care hospital assisted reproduction program.. Ten women at high risk for OHSS (mean E(2) level 9401 +/- 585 pg/mL on the day of hCG administration).. Cancellation of ET and dual RAS blockage with an angiotensin receptor blocker (candesartan cilexetil) and an angiotensin-converting enzyme inhibitor (enalapril) starting from day 1 after oocyte retrieval. Embryos were cryopreserved and transferred in subsequent cycles.. Development of OHSS and pregnancy and live birth rates after frozen-thawed ETs.. While eight women did not develop OHSS, two women (20%) developed severe OHSS requiring hospitalization. Subsequent frozen-thawed ETs resulted in an 80% clinical pregnancy rate and 40% live birth rate.. Dual RAS blockage with total embryo cryopreservation is a relatively new strategy that was proposed for use in patients at high risk for OHSS. It should be stressed that complete elimination of the syndrome is not possible with this treatment. Subsequent pregnancy rates with the transfer of frozen-thawed embryos are high.

Topics: Adult; Angiotensin Receptor Antagonists; Benzimidazoles; Biphenyl Compounds; Combined Modality Therapy; Cryopreservation; Embryo Transfer; Enalapril; Female; Fertilization in Vitro; Humans; Male; Ovarian Hyperstimulation Syndrome; Risk Assessment; Risk Factors; Tetrazoles; Treatment Outcome

Circulating adhesion molecules may have a prognostic significance as markers of endothelial damage. Drugs which inhibit the renin-angiotensin system may be effective in reducing circulating or tissue adhesion molecules, albeit data available are scarce. The aim of the study was to investigate the effects of an angiotensin-converting enzyme (ACE) inhibitor, enalapril and a highly selective angiotensin receptor blocker, candesartan cilexetil, on circulating adhesion molecules in a large sample of patients with non-insulin-dependent diabetes mellitus (NIDDM). The study was comparative, multicenter, randomized and double blind, with two parallel groups.. NIDDM patients with a diagnosis of mild (grade 1) essential hypertension were included in the study, at the end of a 2-week placebo run-in period. The primary end-point of the study was to evaluate changes of intercellular adhesion molecule-1 (ICAM-1) plasma levels during treatment. The secondary end-points were: changes in vascular cells adhesion molecule-1 (VCAM-1), von Willebrand factor (vWF), fibrinogen and plasminogen activator inhibitor-1 (PAI-1) circulating levels and of urinary albumin excretion rate (AER) as well; 129 patients were randomized: 66 in the candesartan group and 63 in the enalapril group, 118 of them completed the scheduled 24-week treatment period.. Candesartan and enalapril equally reduced circulating level of ICAM-1 and exerted comparable effects on changes of other adhesion molecules and coagulation factors. A similar blood pressure-lowering effect was observed with the two drugs (candesartan: from 148/90 +/- 11/8 to 132/82 +/- 12/7 mmHg, P < 0.01, enalapril: from 148/91 +/- 12/8 to 131/85 +/- 14/6 mmHg, P < 0.01). Candesartan was more effective than enalapril in the reduction of albuminuria (P < 0.05 between treatments), although urinary protein excretion can be considered normal in the majority of patients. The two drugs were comparable in terms of adverse events reported.. Candesartan and enalapril showed similar effects on blood pressure and on circulating adhesion molecules. In this study urinary protein excretion was reduced more by candesartan.

Topics: Adult; Aged; Albuminuria; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Arteriosclerosis; Benzimidazoles; Biomarkers; Biphenyl Compounds; Blood Pressure; Diabetes Mellitus, Type 2; Double-Blind Method; Enalapril; Female; Fibrinogen; Humans; Hypertension; Intercellular Adhesion Molecule-1; Male; Middle Aged; Plasminogen Activator Inhibitor 1; Tetrazoles; Vascular Cell Adhesion Molecule-1; von Willebrand Factor

Structural alterations of subcutaneous small resistance arteries are associated with a worse clinical prognosis in hypertension and noninsulin-dependent diabetes mellitus (NIDDM). However, no data are presently available about the effects of antihypertensive therapy on vascular structure in hypertensive patients with NIDDM. Therefore, we have investigated the effect of an angiotensin-converting enzyme inhibitor, enalapril, and a highly selective angiotensin receptor blocker, candesartan cilexetil, on indices of subcutaneous small resistance artery structure in 15 patients with mild hypertension and NIDDM. Eight patients were treated with candesartan (8 to 16 mg per day) and 7 with enalapril (10 to 20 mg per day) for 1 year. Each patient underwent a biopsy of the subcutaneous fat from the gluteal region at baseline and after 1 year of treatment. Small arteries were dissected and mounted on a micromyograph and the media-to-internal lumen ratio was evaluated; moreover, endothelium-dependent vasodilation to acetylcholine was assessed. A similar blood pressure-lowering effect and a similar reduction of the media-to-lumen ratio of small arteries was observed with the 2 drugs. Vascular collagen content was reduced and metalloproteinase-9 was increased by candesartan, but not by enalapril. Changes of circulating indices of collagen turnover and circulating matrix metalloproteinase paralleled those of vascular collagen. The 2 drugs equally improved endothelial function. In conclusion, antihypertensive treatment with drugs that inhibit the renin-angiotensin-aldosterone system activity is able to correct, at least in part, alterations in small resistance artery structure in hypertensive patients with NIDDM. Candesartan may be more effective than enalapril in reducing collagen content in the vasculature.

Topics: Adult; Aged; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Arteries; Benzimidazoles; Biphenyl Compounds; Diabetes Mellitus, Type 2; Echocardiography; Enalapril; Endothelium, Vascular; Female; Humans; Hypertension; Male; Matrix Metalloproteinase 9; Middle Aged; Subcutaneous Tissue; Tetrazoles

The objective of this study was to compare the antihypertensive efficacy and tolerability of candesartan cilexetil (CC) with that of enalapril (E) and placebo (P) in hypertensives by clinic and ambulatory blood pressure (BP).. The study was an Italian multicenter, randomized, double-blind, parallel group trial including 227 mild to moderate essential hypertensives (age range, 18 to 70 years). After 4 weeks of P, patients were randomized to 8 weeks of treatment with P or CC (4 mg) or E (10 mg) once daily, which was eventually increased to 8 mg and 20 mg once daily in nonresponders. At the end of each study phase, trough BP was measured by conventional sphygmomanometry and ambulatory BP was monitored over 24 h by a Spacelabs device. Analysis of 24-h BP profile included calculation of 24-h, daytime, nighttime, and hourly average values.. In the 178 patients evaluable per protocol, at the end of 8 weeks of treatment, trough systolic (S) and diastolic (D) BP were similarly reduced by both active treatments (13 +/- 12 and 10 +/- 7 mm Hg for CC and 14 +/- 12 and 10 +/- 7 mm Hg for E) and significantly more by both treatments than by P (6 +/- 11 and 7 +/- 8 mm Hg, P < .01 v CC and E). In the 85 patients with valid 24-h recordings reduction in 24-h BP was again similar for the two active groups. The antihypertensive effect was still evident during h 23 and 24 after the last dose for both active treatments (8 +/- 20 v 5 +/- 18 mm Hg for SBP and 4 +/- 12 v 6 +/- 13 mm Hg for DBP, CC v E, respectively) but not for P. Heart rate was not significantly modified by either active treatment. The incidence of adverse events was greater in the E than in the CC group.. Our study provides evidence that CC at a dose of 4 to 8 mg is as effective as E at a dose of 10 to 20 mg over 24 h, but is better tolerated than E.

Topics: Adult; Aged; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Double-Blind Method; Enalapril; Female; Heart Rate; Humans; Hypertension; Male; Middle Aged; Tetrazoles

To determine the antihypertensive efficacy, effect duration and safety of the angiotensin II type 1 receptor blocker candesartan cilexetil and the angiotensin converting enzyme inhibitor enalapril once daily in patients with mild to moderate hypertension.. A multicenter, randomised, double-blind parallel group study was performed in Finland, France, the Netherlands, Spain and Sweden. Three-hundred-and-ninety-five men and women in the age range 20-80 years with primary hypertension were randomised to an 8-week double-blind treatment period with either candesartan cilexetil 8-16 mg or enalapril 10-20 mg once daily, with forced dose titration after 4 weeks. Non-invasive ambulatory blood pressure was measured for 36 h at baseline and after 8 weeks. The primary efficacy variable was the change in mean diastolic and systolic ambulatory blood pressure 22-24 h post-dose.. There was a significant difference in the adjusted mean difference for the change from baseline to week 8 between candesartan cilexetil and enalapril 22-24 h post-dose by -3.5 mmHg (95% confidence interval, CI: -6.8 to -0.3 mmHg; p < 0.032) in ambulatory systolic blood pressure and -3.0 mmHg (95% CI: -5.1 to -0.8 mmHg; p < 0.008) in ambulatory diastolic blood pressure. There was a significant difference in adjusted mean daytime ambulatory blood pressure 24-36 h post-dose by -4.2 mmHg (95% CI: -6.8 to -1.6 mmHg; p < 0.002)/-3.5 mmHg (95% CI: -5.1 to -1.8 mmHg; p < 0.001). Both drugs were generally well tolerated.. The results of the present study suggest that advantages may be attributed to the use of candesartan cilexetil, as compared to enalapril in the treatment of patients with essential hypertension. In comparison with enalapril 20 mg, candesartan cilexetil 16 mg more effectively lowered blood pressure at trough and in particular on the day following the day after the last dose.

Topics: Adult; Aged; Aged, 80 and over; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Double-Blind Method; Enalapril; Female; Heart Rate; Humans; Hypertension; Male; Middle Aged; Prodrugs; Tetrazoles; Therapeutic Equivalency; Time Factors

Few studies have prospectively and systematically explored the factors that acutely precipitate exacerbation of congestive heart failure (CHF) in patients with left ventricular dysfunction. Knowledge of such factors is important in designing measures to prevent deterioration of clinical status. The objective of this study was to prospectively describe the precipitants associated with exacerbation of CHF status in patients enrolled in the Randomized Evaluation of Strategies for Left Ventricular Dysfunction Pilot Study.. We conducted a 2-stage, multicenter, randomized trial in 768 patients with CHF who had an ejection fraction of less than 40%. Patients were randomly assigned to receive enalapril maleate, candesartan cilexetil, or both for 17 weeks, followed by randomization to receive metoprolol succinate or placebo for 26 weeks. Investigators systematically documented information on clinical presentation, management, and factors associated with the exacerbation for any episode of acute CHF during follow-up.. A total of 323 episodes of worsening of CHF occurred in 180 patients during 43 weeks of follow-up; 143 patients required hospitalization, and 5 died. Factors implicated in worsening of CHF status included noncompliance with salt restriction (22%); other noncardiac causes (20%), notably pulmonary infectious processes; study medications (15%); use of antiarrhythmic agents in the past 48 hours (15%); arrhythmias (13%); calcium channel blockers (13%); and inappropriate reductions in CHF therapy (10%).. A variety of factors, many of which are avoidable, are associated with exacerbation of CHF. Attention to these factors and patient education are important in the prevention of CHF deterioration.

Topics: Adrenergic beta-Antagonists; Aged; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Disease Progression; Double-Blind Method; Drug Therapy, Combination; Enalapril; Female; Heart Failure; Hospitalization; Humans; Male; Metoprolol; Middle Aged; Patient Compliance; Precipitating Factors; Prospective Studies; Severity of Illness Index; Stroke Volume; Tetrazoles; Treatment Outcome; Ventricular Dysfunction, Left

The aim of this study was to evaluate the occurrence of dry cough during treatment with candesartan cilexetil, enalapril, or placebo in patients with hypertension and a history of angiotensin converting enzyme (ACE)-inhibitor-related cough. Patients with confirmed cough during an enalapril (10 mg) challenge period, followed by no cough during a placebo dechallenge period were randomized to 8 weeks of double-blind treatment with candesartan cilexetil (8 mg) (n = 62), enalapril (10 mg) (n = 66), or placebo (n = 26). Incidence and severity of dry cough was evaluated by the symptom assessment questionnaire, frequency of dry cough by a visual analog scale, and the possible impact on quality of life by the minor symptom evaluation (MSE) profile. The percentage of patients with cough was significantly lower with candesartan cilexetil (35.5%) than with enalapril (68.2%, P < .001), and did not differ between candesartan cilexetil and placebo (26.9%, P > .20). Patients coughed less frequently and with less severe cough with candesartan cilexetil than with enalapril, and similarly with candesartan cilexetil and placebo. Changes in the MSE profile were minor, although candesartan cilexetil had better scores for contentment than placebo (P = .03), and also tended to be associated with better sleep than enalapril (P = .08). In hypertensive patients with ACE-inhibitor-induced cough, the incidence, frequency, and severity of dry cough was significantly lower with candesartan cilexetil than with enalapril, and no different from that found with placebo.

Topics: Adult; Aged; Aged, 80 and over; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Cough; Double-Blind Method; Enalapril; Female; Humans; Hypertension; Incidence; Male; Middle Aged; Quality of Life; Safety; Surveys and Questionnaires; Tetrazoles; Treatment Outcome

The aim of this large, randomized, double-blind, parallel-group study in hypertensive women was to compare the antihypertensive efficacy and effects on subjective symptoms and quality of life of the new angiotensin II type 1 (AT1) receptor blocker candesartan cilexetil, the angiotensin-converting enzyme inhibitor enalapril, and the diuretic hydrochlorothiazide (HCTZ). Women, aged 40 to 69 years, with a seated diastolic blood pressure (DBP) of 95 to 115 mm Hg, were randomized to candesartan cilexetil, 8 to 16 mg (n = 140), enalapril, 10 to 20 mg (n = 146), or HCTZ, 12.5 to 25 mg (n = 143), for 12 weeks; the higher doses were used if DBP was greater than 90 mm Hg after 6 weeks. Candesartan cilexetil lowered seated blood pressure by 17/11 and 19/11 mm Hg after 6 and 12 weeks of treatment, respectively. This reduction was greater (P < .01) than with enalapril (12/8 and 13/9 mm Hg) or HCTZ (12/7 and 13/8 mm Hg). The proportions of patients with controlled DBP (< 90 mm Hg) after 12 weeks of treatment with candesartan cilexetil, enalapril, or HCTZ were 60%, 51%, and 43%, respectively. Patients experienced less dry cough (P < 0.001) with candesartan cilexetil or HCTZ than with enalapril. No treatment differences were found in the incidence of dizziness and quality of life was well maintained in all groups. Compared with candesartan cilexetil and enalapril, HCTZ increased uric acid and decreased serum potassium (P < .001). In conclusion, candesartan cilexetil reduced blood pressure more effectively and was better tolerated than enalapril or HCTZ in women with mild to moderate hypertension.

Topics: Adult; Aged; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Diuretics; Double-Blind Method; Enalapril; Female; Humans; Hydrochlorothiazide; Hypertension; Middle Aged; Quality of Life; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Sodium Chloride Symporter Inhibitors; Tetrazoles

Topics: Adolescent; Adult; Aged; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Enalapril; Female; Humans; Hypertension; Male; Middle Aged; Tetrazoles

Topics: Adolescent; Adult; Aged; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Double-Blind Method; Enalapril; Humans; Hypertension; Middle Aged; Tetrazoles

Although the activity of the renin-angiotensin system is known to decrease with age, the antihypertensive efficacy of angiotensin-converting enzyme (ACE) inhibitors has been demonstrated in the elderly. To examine the role of the renin-angiotensin system in hypertension in the elderly, we evaluated the antihypertensive response to enalapril and to TCV-116, an angiotensin II type-1 receptor antagonist, in elderly patients with essential hypertension. A single oral dose of enalapril (10 mg) increased plasma renin activity (PRA) and reduced the angiotensin II concentration, whereas a single oral dose of TCV-116 (4 mg) increased both PRA and the angiotensin II concentration. Blood pressure was significantly reduced by these drugs from 4 h after administration. Basal levels of PRA and angiotensin II declined with age. However, the changes in blood pressure produced by either TCV-116 or enalapril did not correlate with age. These results suggest that the activity of the renin-angiotensin system in plasma declines with age, and that the extrarenal renin-angiotensin system may play a role in hypertension in the elderly.

Topics: Adult; Aged; Aging; Angiotensin II; Angiotensin Receptor Antagonists; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Enalapril; Humans; Hypertension; Middle Aged; Prodrugs; Renin; Renin-Angiotensin System; Tetrazoles

The aim of this study was to determine the stability of three ester prodrugs, chloramphenicol succinate, enalapril and candesartan cilexetil, in human proximal small intestinal fluid (HIF), dog proximal small intestinal fluids (DIF) and simulated intestinal fluid (FaSSIF), with the addition of pancreatin. The total protein content in the proximal jejunal fluids was determined in HIF and DIF, respectively. Candesartan cilexetil was significantly degraded in HIF (initial t(1/2(0-5 min))=5.4 ± 0.5 min) and in DIF (initial t(1/2(0-5 min))=5.7 ± 0.1 min), while chloramphenicol succinate and enalapril were stable in both media. The degradation of candesartan cilexetil was shown to be mediated by enzymes following Michaelis-Menten enzyme kinetics and was inhibited by addition of esterase inhibitors. The enzymatic capacity reflected by V(max) was 4-fold higher in DIF than in HIF and correlated to its 2-fold higher protein concentration. The degradation of candesartan cilexetil in the FaSSIF-pancreatin solution was slower (t(1/2)=207 ± 34 min) than the degradation in both HIF and DIF. Changing the pH to the enzyme optima or increasing the amount of pancreatin, increased the degradation rate of candesartan cilexetil, but not in the magnitude as in HIF. As a result, two in vitro models, based on in vivo intestinal fluids, were developed using candesartan cilexetil as a model drug. The DIF seems to be a reasonably good model for HIF, although the degradation capacity seems to be somewhat higher, possibly due to the higher enzyme concentration in DIF. Future investigations will develop novel enzymatic based in vitro models for rapid assessment and biopharmaceutical screening tools for prodrugs.

Topics: Adolescent; Adult; Animals; Benzimidazoles; Biopharmaceutics; Biphenyl Compounds; Body Fluids; Chloramphenicol; Dogs; Drug Stability; Enalapril; Enzyme Inhibitors; Humans; Intestinal Secretions; Intestine, Small; Male; Pancreatin; Prodrugs; Tetrazoles; Young Adult

Controlling hypertension by angiotensin converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB), mechanisms that inhibit later pathway steps in the renin-angiotensin system (RAS), have clinically afforded protection against cardiac and renal disease.. In order to determine if blocking the RAS rate-limiting step of angiotensin II generation via renin inhibition could afford similar end organ protection in a human-relevant preclinical model, this study investigated the cardiac and renal effects of a nonpeptide, piperidine renin inhibitor (RI; 100 mg/kg/day PO) in double transgenic mice (dTGM) which express both human renin and angiotensinogen genes. RI was compared to the ARB, candesartan (3 mg/kg/day PO), and to the ACEI, enalapril (60 mg/kg/day PO) in a 4-week dosing paradigm. These doses of RI, ACEI and ARB were previously found to normalize mean blood pressure (MBP) to 110 + 3, 109 + 7 and 107 + 6 mmHg, respectively, after 1 day of treatment.. In the dTGM, PRA, plasma aldosterone, GFR, microalbuminuria and left ventricular free wall thickness (LVH) were higher than in the wild type C57BL/6 mice. Microalbuminuria and LVH were significantly reduced by 93% and 9% for the RI, 83% and 13% for enalapril and 73% and 6% for candesartan, respectively. PRA and aldosterone were reduced by the RI 56% and 23%, respectively. These results suggest that the RI provides protection against cardiac and renal disease, similar to ARB and ACEI.

Topics: Administration, Oral; Albuminuria; Aldosterone; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Angiotensinogen; Animals; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Cardiotonic Agents; Drug Administration Schedule; Enalapril; Female; Glomerular Filtration Rate; Humans; Hypertrophy, Left Ventricular; Kidney Diseases; Mice; Mice, Inbred C57BL; Mice, Transgenic; Molecular Structure; Piperidines; Quinolines; Renin; Renin-Angiotensin System; Tetrazoles; Time Factors; Ultrasonography

Although angiotensin-converting enzyme inhibitors (ACEIs) have been shown to reduce left ventricular remodeling after acute myocardial infarction (AMI), the effects of angiotensin receptor blockers have yet to be established. This study was conducted to examine the effects of candesartan on left ventricular remodeling after AMI. Consecutive AMI patients were assigned to a candesartan group or ACEI group after successful coronary intervention. The patients in the candesartan group (n = 77, mean age, 62.8 +/- 1.3) received candesartan and the patients in the ACEI group (n = 80, mean age, 63.3 +/- 1.2) received lisinopril, enalapril, or trandolapril. Four mg was the most frequent dose in the candesartan group at 6 months. Lisinopril, enalapril, and trandolapril were administered to 52%, 27%, and 21% of the patients in the ACEI group, respectively. No significant differences in the incidences of cardiac death, nonfatal MI, or hospitalization for heart failure (P = NS) were found between the groups. The candesartan group exhibited a somewhat higher percent increase in left ventricular ejection fraction and significantly lower percent increases in left ventricular end-diastolic volume index and left ventricular end-systolic volume index compared to the ACEI group (P < 0.05, P < 0.05, respectively). Candesartan is more effective than ACEI in preventing left ventricular remodeling after AMI.

Topics: Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Benzimidazoles; Biphenyl Compounds; Enalapril; Female; Humans; Indoles; Lisinopril; Male; Middle Aged; Myocardial Infarction; Tetrazoles; Ventricular Function, Left; Ventricular Remodeling

To retrospectively investigate the effect of carvedilol and spironolactone plus furosemide, administered concomitantly with an angiotensin II converting enzyme inhibitor (ACE-I) or an angiotensin II receptor blocker (ARB) to patients with chronic heart failure (CHF).. Patients with CHF, who visited Departments of Cardiovascular Internal Medicine at the National Hospital Organization Osaka Medical Center, were enrolled for this study. Serum potassium, blood urea nitrogen (BUN), serum creatinine (Scr) and serum sodium were measured in every patient at the time of start of treatment and after 3 and 12 months of treatment. Data from patients in groups A (20 mg/day carvedilol + 25 mg/day spironolactone + 40 mg/day furosemide + an ACE-I) and B (20 mg/day carvedilol + 25 mg/day spironolactone + 40 mg/day furosemide + ARB) were compared.. When 20 mg/day carvedilol plus 25 mg/day spironolactone plus 5 mg/day enalapril maleate (enalapril, group A) or 8 mg/day candesartan cilexetil (candesartan, group B) plus 40 mg/day furosemide were used concomitantly, the mean serum potassium increased significantly in both groups of patients. Seven of 59 (11.9%) patients had hyperkalemia (>5.5 mEq/L) during 12 months of treatment whereas 8.5% of patients (five of 59) had hypokalemia (< or =3.5 mEq/L).. When carvedilol is used concomitantly with spironolactone, furosemide and enalapril or candesartan, it is necessary to monitor serum potassium concentration, even if spironolactone is administered at a low dose of 25 mg/day.

Topics: Adult; Aged; Aged, 80 and over; Benzimidazoles; Biphenyl Compounds; Carbazoles; Carvedilol; Drug Therapy, Combination; Enalapril; Female; Furosemide; Heart Failure; Humans; Hyperkalemia; Male; Middle Aged; Potassium; Propanolamines; Retrospective Studies; Spironolactone; Tetrazoles

Two endothelium-derived factors, endothelin (ET), a vasoconstrictor, and vascular endothelial growth factor (VEGF), an angiogenic factor are thought to be involved in the pathogenesis of diabetic vascular complications. The aim of this study was to determine the effects of an angiotensin II type I (AT-1) receptor antagonist and an ACE inhibitor on the pathogenesis of VEGF and ET-1-mediated kidney disease in STZ-induced diabetic rats. Two days after STZ administration, diabetic rats were treated for 8 weeks with enalapril maleate, an ACE inhibitor, candesartan cilexetil, an AT-1 receptor antagonist, or saline. Urinary albumin and N-acetyl beta-D glucosaminidase (NAG) excretion as well as the VEGF protein content in the kidney were all found to be elevated in diabetic rats. Administration of enalapril maleate or candesartan cilexetil decreased the level of microalbuminuria and NAG excretion in diabetic rats. Administration of enalapril maleate also suppressed the elevated renal VEGF protein content in these animals while candesartan cilexetil treatment had no effect. Serum ET-1 and VEGF levels were unchanged by these treatments. These data support a role for AT-1 receptor antagonists and ACE inhibitors in the prevention of diabetic nephropathy, and suggest that the former may work by reducing renal VEGF levels.

Topics: Albuminuria; Analysis of Variance; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Glucose; Blotting, Western; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Diabetic Nephropathies; Disease Progression; Enalapril; Endothelin-1; Kidney; Male; Rats; Rats, Wistar; Streptozocin; Tetrazoles; Vascular Endothelial Growth Factor A

Angiotensin receptor blocker (ARB) and angiotensin-converting enzyme (ACE) inhibitor (ACEI) each act in a different manner to prevent myocardial fibrosis and left ventricular (LV) stiffness in animals with pathways in the heart for generating ANG II as well as ACE. A model of pacing-induced congestive heart failure (CHF) was used to test the central hypothesis that ARB + ACEI prevents myocardial fibrosis and decreases LV stiffness to a greater extent than ARB or ACEI alone. Thirty-five dogs were assigned to the following treatment protocols on the 8th day of a 4-wk pacing schedule: 1) rapid ventricular pacing, 2) ARB (candesartan cilexetil, 1.5 mg.kg(-1).day(-1)) with pacing, 3) ACEI (enalapril, 1.9 mg.kg(-1).day(-1)) with pacing, 4) ARB (candesartan cilexetil, 0.75 mg.kg(-1).day(-1)) + ACEI (enalapril, 0.95 mg.kg(-1).day(-1)) with pacing, and 5) sham operation. The LV stiffness coefficient was significantly increased after rapid pacing but was significantly lower with ARB + ACEI than with ARB or ACEI alone. The collagen volume fraction and mRNA levels of collagen I and III, which were increased by rapid pacing, were significantly lower with ARB + ACEI than with ARB or ACEI alone. Thus ARB + ACEI prevents myocardial fibrosis and decreases LV stiffness during the progression of CHF compared with ARB or ACEI alone.

Topics: Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Animals; Benzimidazoles; Biphenyl Compounds; Cardiac Volume; Collagen Type I; Collagen Type III; Dogs; Drug Therapy, Combination; Enalapril; Fibrosis; Gene Expression; Heart Failure; Male; Myocardium; Norepinephrine; Tetrazoles; Ventricular Function, Left; Ventricular Pressure

We previously demonstrated that the angiotensin converting enzyme (ACE) inhibitor, enalapril, prevents the age-related impairment of endothelium-dependent hyperpolarization and relaxation mediated by endothelium-derived hyperpolarizing factor (EDHF).. To test whether angiotensin II type 1 (AT1) receptor antagonists would also improve age-related endothelial dysfunction.. Normotensive Wistar-Kyoto (WKY) rats were treated for 3 months with either the AT1 receptor antagonist, candesartan cilexetil (3.5 mg/kg per day; candesartan group), or the ACE inhibitor, enalapril (20 mg/kg per day; enalapril group), from 9 to 12 months of age. Untreated 12-month-old WKY rats (old group) served as controls (n = 7-12).. The two treatments decreased systolic blood pressure comparably. EDHF-mediated hyperpolarization in response to acetylcholine (ACh; 10(-5) mol/l) in the presence of norepinephrine in mesenteric arteries was improved in both the candesartan and enalapril groups to a similar extent compared with the old group (candesartan group, -24 +/- 3 mV; enalapril group, -21 +/- 2 mV; old group, -13 +/- 2 mV). EDHF-mediated relaxation was similarly improved in the candesartan and enalapril groups (maximum relaxation: candesartan group, 70 +/- 7%; enalapril group, 63 +/- 8%; old group, 33 +/- 9%). Hyperpolarization and relaxation responses to levcromakalim, an ATP-sensitive K+-channel opener, were similar in all groups.. These findings suggest that the AT1 receptor antagonist is as effective as the ACE inhibitor in improving the age-related decline in EDHF-mediated hyperpolarization and relaxation in normotensive rats. Thus AT1 receptor antagonists might serve as novel tools with which to prevent endothelial dysfunction associated with aging.

Topics: Acetylcholine; Aging; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Benzimidazoles; Biological Factors; Biphenyl Compounds; Dose-Response Relationship, Drug; Electrophysiology; Enalapril; Endothelium, Vascular; In Vitro Techniques; Male; Mesenteric Arteries; Rats; Rats, Inbred WKY; Receptor, Angiotensin, Type 1; Tetrazoles; Vasodilator Agents

The present study was designed to clarify the role of angiotensin II (Ang II) in modulating renal tumor necrosis factor (TNF)-alpha and interleukin-6 (IL-6) production and to investigate the effect of one dose of Ang II inhibitor on cytokines production following lipopolysaccharide (LPS) to cause endotoxemia. Two studies were performed: 1) Ang II was infused intravenously at a rate of 0.2 microg/kg per minute for 4 h in rats and then kidneys were collected to assay TNF-alpha and IL-6 mRNA levels; 2) Four-week-old Wistar rats pre-treated with angiotensin-converting enzyme inhibitor, enalapril, or type I Ang II-receptor antagonist, TCV-116, were injected with LPS (0.1, 0.5, 1.0 mg, i.p.), and then 2 or 4 h later, kidneys were collected to assay TNF-alpha, IL-6, renin and angiotensinogen mRNA levels. After a 4-h intravenous infusion of Ang II, renal TNF-alpha or IL-6 mRNA level significantly increased 1.9-fold or 2.1-fold (each P<0.05) to the control level, respectively. LPS stimulated TNF-alpha, IL-6 and angiotensinogen mRNA levels in the kidney but in rats given enalapril or TCV-116, LPS-induced IL-6 and TNF-alpha mRNA levels were completely suppressed (each P<0.05). This suggests that a single dose of renin-angiotensin system inhibitor suppressed renal IL-6 and TNF-alpha production and may prevent cytokine-induced renal damage during endotoxemia.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Angiotensinogen; Animals; Benzimidazoles; Biphenyl Compounds; Blotting, Northern; Cytokines; Enalapril; Endotoxins; Gene Expression Regulation; Interleukin-6; Kidney; Lipopolysaccharides; Male; Rats; Rats, Wistar; Receptor, Angiotensin, Type 1; Renin; Renin-Angiotensin System; RNA, Messenger; Tetrazoles; Tumor Necrosis Factor-alpha

Spontaneously hypercholesterolemic (SHC) rats exhibit hypercholesterolemia, proteinuria and focal glomerulosclerosis with age, and they finally die as a result of renal failure. In this study, the renoprotective effects of candesartan cilexetil, an angiotensin II type 1 receptor antagonist, and enalapril, an angiotensin I converting enzyme inhibitor, were examined in SHC rats. Candesartan cilexetil (0.1 and 1 mg /kg) and enalapril (10 mg/kg) were administered orally to 10-week-old SHC rats for a 6-week period. Candesartan cilexetil (1 mg/kg) and enalapril (10 mg/kg) significantly inhibited proteinuria and hypercholesterolemia to a similar extent. In untreated 16-week-old SHC rats, glomerulosclerosis, basophilic change, cast formation and interstitial mononuclear cell infiltration were observed. Candesartan cilexetil (1 mg/kg) inhibited all of these histological changes. Enalapril inhibited glomerulosclerosis and cast formation. These results show that candesartan cilexetil and enalapril have renal protective effects in SHC rats. Thus, angiotensin II might play an important role in renal pathogenesis in a model of focal glomerulosclerosis with hypercholesterolemia.

Topics: Albuminuria; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Benzimidazoles; Biphenyl Compounds; Body Weight; Cholesterol; Enalapril; Glomerulosclerosis, Focal Segmental; Hypercholesterolemia; Indicators and Reagents; Kidney Diseases; Kidney Function Tests; Male; Rats; Rats, Sprague-Dawley; Receptor, Angiotensin, Type 1; Tetrazoles

Wistar fatty (WF) rats have a genetic predisposition to hyperglycemia, polyuria, hyperinsulinemia, hyperlipidemia, obesity and nephropathy. These phenotypic characteristics are similar to those observed in obese patients with non-insulin-dependent diabetes mellitus (NIDDM) nephropathy. In this study, the effects of two types of renin-angiotensin system inhibitors, an angiotensin II type 1-receptor antagonist (AT1A) and an angiotensin I-converting enzyme inhibitor (ACEI), on renal injury in WF rats were studied during the progressive phase of diabetic nephropathy. An AT1A, candesartan cilexetil (1 mg/kg), and an ACEI, enalapril (10 mg/kg), were administered orally once a day for 12 weeks, beginning when the rats were 27-week-old and already showed diabetic nephropathy and obesity. Both drugs prevented an increase in proteinuria during the experimental period. Furthermore, after 4-week intervention, the levels of proteinuria were markedly lower in drug-treated rats. At the end of the experiment, both drugs prevented the development of glomerular lesions without affecting glucose metabolism and obesity. In conclusion, the inhibition of angiotensin II activity ameliorated both existing proteinuria and the progression of proteinuria, resulting in preservation of glomerular structure. Thus angiotensin II plays important roles in the development and the progression of nephropathy in genetically obese diabetic WF rats.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Cholesterol; Creatinine; Diabetes Mellitus, Type 2; Disease Progression; Enalapril; Glomerular Mesangium; Male; Proteins; Proteinuria; Rats; Rats, Wistar; Rats, Zucker; Receptor, Angiotensin, Type 1; Renin-Angiotensin System; Tetrazoles; Triglycerides

Angiotensin-converting enzyme (ACE) inhibitor improves the impaired hyperpolarization and relaxation to acetylcholine (ACh) via endothelium-derived hyperpolarizing factor (EDHF) in arteries of spontaneously hypertensive rats (SHR). We tested whether the angiotensin type 1 (AT(1)) receptor antagonist also improves EDHF-mediated responses and whether the combined AT(1) receptor blockade and ACE inhibition exert any additional effects. SHR were treated with either AT(1) receptor antagonist TCV-116 (5 mg. kg(-1). d(-1)) (SHR-T), enalapril (40 mg. kg(-1). d(-1)) (SHR-E), or their combination (SHR-T&E) from 8 to 11 months of age. Age-matched, untreated SHR (SHR-C) and Wistar Kyoto (WKY) rats served as controls (n=8 to 12 in each group). Three treatments lowered blood pressure comparably. EDHF-mediated hyperpolarization to ACh in mesenteric arteries in the absence or presence of norepinephrine was significantly improved in all treated SHR. In addition, the hyperpolarization in the presence of norepinephrine was significantly greater in SHR-T&E than in SHR-E (ACh 10(-5) mol/L with norepinephrine: SHR-C -7; SHR-T -19; SHR-E -15; SHR-T&E -22; WKY -14 mV). EDHF-mediated relaxation, assessed in the presence of indomethacin and N:(G)-nitro-L-arginine, was markedly improved in all treated SHR. Hyperpolarization and relaxation to levcromakalim, a direct opener of ATP-sensitive K(+)-channel, were similar in all groups. These findings suggest that AT(1) receptor antagonists are as effective as ACE inhibitors in improving EDHF-mediated responses in SHR. The beneficial effects of the combined AT(1) receptor blockade and ACE inhibition appears to be for the most part similar to those of each intervention.

Topics: Acetylcholine; Administration, Oral; Angiotensin Receptor Antagonists; Animals; Anti-Inflammatory Agents, Non-Steroidal; Antihypertensive Agents; Benzimidazoles; Biological Factors; Biphenyl Compounds; Cromakalim; Disease Models, Animal; Drug Therapy, Combination; Enalapril; Endothelium, Vascular; Enzyme Inhibitors; Hypertension; In Vitro Techniques; Indomethacin; Male; Nitroarginine; Norepinephrine; Potassium Channels; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Renin-Angiotensin System; Tetrazoles

We have investigated the influence of a novel angiotensin II type 1 receptor antagonist, candesartan cilexetil, on the oxidative state of renal tissue and renal function in 5/6 nephrectomized rats, and compared its effects with those of an angiotensin-converting enzyme inhibitor, enalapril. Candesartan cilexetil (1 and 5 mg/kg per day), enalapril (5 mg/kg per day) and vehicle were orally administered once daily for 16 weeks after 5/6 nephrectomy. There was a marked degree of proteinuria evident prior to treatment, an average of 5.69 mg/mg creatinine in the nephrectomized rats, vs 1 to 2 mg/mg creatinine in the control group matched for species and body weight. Inhibition of development of proteinuria by candesartan cilexetil was dose dependent. Enalapril also significantly blunted the rise in urinary protein. Malondi-aldehyde content in the homogenate from the renal cortex increased significantly in the nephrectomized rats compared to control animals. This elevation of malondi-aldehyde content was unaffected by administration of either candesartan cilexetil or enalapril. Antioxidative enzyme (glutathione peroxidase, superoxide dismutase, and catalase) activities in the renal tissue were not affected by any active treatment. Elevation of lipid peroxide in remnant renal tissue suggests that oxidative stress may contribute to the progression of renal injury in the nephrectomized rats. Neither candesartan cilexetil nor enalapril affected antioxidant defenses in renal tissue in nephrectomized rats, indicating that mechanisms other than alteration in oxidative stress are involved in the renoprotective effects of candesartan cilexetil and enalapril.

Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Catalase; Disease Models, Animal; Disease Progression; Enalapril; Glutathione Peroxidase; Kidney; Kidney Function Tests; Male; Nephrectomy; Organ Size; Oxidation-Reduction; Prodrugs; Proteinuria; Rats; Rats, Wistar; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Superoxide Dismutase; Tetrazoles; Thiobarbituric Acid Reactive Substances; Treatment Outcome

Inhibition of the renin-angiotensin system by both angiotensin II type 1 receptor antagonists (AT1As) and angiotensin I-converting enzyme inhibitors (ACEIs) shows renoprotective effects in rats with chronic renal failure when treatment is started in the early phase of renal injury. In this study, we examined the renal protective effects of candesartan cilexetil (TCV-116), an AT1A, and enalapril, an ACEI, in the progressive phase of renal injury in 5/6 nephrectomized rats.. Candesartan cilexetil (1 mg/kg/day) and enalapril (10 mg/kg/day) were orally administered once a day for 4 weeks (the short-term experiment) or 16 weeks (the long-term experiment) to 5/6 nephrectomized rats beginning 15 weeks after the nephrectomy, that is, after they had already showed marked proteinuria.. In vehicle-treated rats, proteinuria, glomerulosclerosis, and interstitial fibrosis developed. Moreover, enhanced expression of transforming growth factor-beta1 (TGF-beta1) in the injured glomeruli was observed. These adverse changes progressed with time, and in the short-term experiment, both drugs inhibited them. In the long-term experiment, the progressive proteinuria and the elevation of blood pressure were similarly attenuated by both drugs. However, candesartan cilexetil significantly inhibited the progression of glomerulosclerosis, the expression of TGF-beta1, and interstitial fibrosis, whereas enalapril did not.. These results indicate that candesartan cilexetil shows potent and long-term preventive effects against the progression of previously developed renal injury.

Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Blood Urea Nitrogen; Creatinine; Dinoprostone; Disease Models, Animal; Enalapril; Kidney Failure, Chronic; Male; Nephrectomy; Proteinuria; Rats; Rats, Sprague-Dawley; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Renin; Tetrazoles; Transforming Growth Factor beta

It was previously observed that a significant regression of structural alterations and endothelial dysfunction in mesenteric small arteries of spontaneously hypertensive rats (SHRs) may be obtained after therapy with angiotensin-converting enzyme (ACE) inhibitors. It is not clear whether angiotensin II-type 1 receptor blockers may share this properties. We evaluated the effects of the ACE inhibitor enalapril and of the angiotensin II-receptor blocker candesartan cilexetil on structural alterations of mesenteric small resistance arteries, on cardiac mass, and on endothelial function in SHRs. Seventy-three rats were included in the study. Sixteen SHRs were treated with enalapril and 21 with candesartan cilexetil, whereas 18 Wistar-Kyoto (WKY) and 18 SHRs were untreated. Enalapril and candesartan cilexetil were administered in the drinking water from weeks 4 to 12 of age. Blood pressure was measured noninvasively every week. The rats were killed at the end of the treatment period, after 3 or 4 days of therapeutic washout. Heart weight/body weight ratio (HW/BW) was measured. Mesenteric arterioles were dissected and mounted on a micromyograph (Mulvany's technique). Then the media-to-lumen ratio (M/L) was evaluated. In addition, endothelium-dependent and endothelium-independent relaxation was evaluated by dose-response curves to acetylcholine (in the presence or absence of a bradykinin-receptor blocker and of indomethacin) and sodium nitroprusside. Systolic blood pressure was significantly reduced by both drugs, compared with untreated SHRs, although the hypotensive effect was greater with enalapril than with candesartan cilexetil. A significant reduction of M/L of mesenteric small arteries and of HW/BW was observed in SHRs treated with candesartan cilexetil or enalapril. A significant improvement of endothelial function, as evaluated by a dose-response to acetylcholine, was observed. The acetylcholine-induced vasodilatation was similar after addition to the organ bath of a selective blocker of bradykinin receptors, thus suggesting a minor role (if any) of the increased local availability of bradykinin, as a consequence of inhibition of ACE, in the improvement of endothelial function observed after enalapril treatment. In addition to a satisfactory antihypertensive effect observed with both drugs, candesartan cilexetil and enalapril were proven to be equally effective in reducing structural alterations in mesenteric small resistance arteries, in normalizing car

Topics: Acetylcholine; Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Dose-Response Relationship, Drug; Enalapril; Endothelium, Vascular; Heart; Hypertension; Mesenteric Arteries; Nitroprusside; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Tetrazoles

The regional hemodynamic effects of candesartan cilexetil (TCV-116), a selective angiotensin II AT1-receptor antagonist, and enalapril, an angiotensin-converting enzyme inhibitor, were compared in conscious spontaneously hypertensive rats (SHR). A 7-day repeated administration study was carried out. TCV-116 (1 mg/kg, p.o.) and enalapril (10 mg/kg, p.o.) reduced blood pressure to the same extent 5 hr after administration on the 1st and the 7th day. At these points, the cardiac index and organ or tissue blood flow were measured by the non-radioactive colored dye-extraction microsphere technique. Repeated administration of TCV-116, and single and repeated administration of enalapril significantly increased renal blood flow without any changes in the cardiac index. TCV-116 and enalapril also tended to increase splanchnic blood flow following the 1st dose but not the 7th dose. No significant changes in blood flow were observed in the brain, heart, adrenal, skin and skeletal muscle. These results suggest that the antihypertensive effects of TCV-116 and enalapril are attributable to the systemic reduction of vascular resistance caused by the dilatation of blood vessels. These hemodynamic effects of TCV-116, like those of enalapril, may be beneficial in the treatment of hypertension.

Topics: Administration, Oral; Adrenal Glands; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Brain; Coronary Circulation; Disease Models, Animal; Enalapril; Hemodynamics; Hypertension; Male; Microspheres; Muscle, Skeletal; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Regional Blood Flow; Renal Circulation; Skin; Splanchnic Nerves; Tetrazoles; Vascular Resistance

Most of the classic functions of the renin-angiotensin system are mediated by type 1 (AT1) angiotensin receptors, of which two subtypes, AT1A and AT1B, have been identified. However, distinct functions for these two AT1 receptors have been difficult to separate. We examined the pressor effects of angiotensin II in Agtr1A -/- mice, which lack AT1A receptors. In enalapril-pretreated Agtr1A -/- mice, angiotensin II caused significant and dose-proportional increases in mean arterial pressure. This pressor response was not blocked by pretreatment with sympatholytic agents but was completely inhibited by the AT1-receptor antagonists, losartan and candesartan, suggesting that it is directly mediated by AT1B receptors. Chronic treatment of Agtr1A -/- mice with losartan reduced systolic blood pressure from 80 +/- 5 to 72 +/- 4 mmHg (P < 0.04), suggesting a role for AT1B receptors in chronic blood pressure regulation. These studies provide the first demonstration of in vivo pressor effects mediated by AT1B receptors and demonstrate that, when AT1A receptors are absent, the AT1B receptor contributes to the regulation of resting blood pressure.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Enalapril; Hexamethonium; Imidazoles; Kidney; Losartan; Mice; Mice, Knockout; Phentolamine; Receptor, Angiotensin, Type 1; Receptors, Angiotensin; Renin; RNA, Messenger; Sympatholytics; Tetrazoles; Time Factors; Transcription, Genetic

The effects of chronic treatment with an angiotensin II receptor antagonist, candesartan cilexetil (TCV-116, 0.1, 1, 10 mg/kg), and an angiotensin converting enzyme inhibitor, enalapril maleate (enalapril, 10 mg/kg), on the development of end-organ damage were examined in stroke-prone spontaneously hypertensive rats (SHRSP). The control SHRSP developed severe hypertension with stroke signs and increased urinary protein excretion. TCV-116 (0.1 mg/kg) reduced the stroke incidence and urinary protein excretion without affecting the blood pressure. TCV-116 (1 and 10 mg/kg) and enalapril reduced blood pressure, the stroke incidence, the urinary indices and left ventricular weight. Circulating renin-angiotensin system (RAS) and renal renin mRNA expression were significantly accelerated or tended to be accelerated in the control SHRSP with end-organ damages. A low dose of TCV-116 tended to reduce the RAS indices in plasma by improving the damages, whereas a high dose (10 mg/kg) increased them by the reflexes with blocking RAS. The present results indicate that chronic All blockade reduces the increase in blood pressure, end-organ damages and RAS related to the damages in SHRSP.

Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Angiotensinogen; Angiotensins; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Cardiomegaly; Cerebrovascular Disorders; Enalapril; Hypertension; Kidney; Male; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Receptors, Angiotensin; Renin; RNA, Messenger; Tetrazoles

The renal protective properties of candesartan cilexetil (TCV-116), an angiotensin II type 1 receptor antagonist (AT1A), and enalapril, an angiotensin I converting enzyme inhibitor (ACEI), were investigated in 5/6 nephrectomized (NX) rats. Candesartan cilexetil (1 mg/kg/day) and enalapril (10 mg/kg/day) were administered orally to 5/6 NX rats for four weeks (during the early phase of disease development) or 16 weeks (through the late phase). In vehicle-treated rats, proteinuria, glomerulosclerosis, interstitial mononuclear cell (MNC) infiltration and interstitial fibrosis developed. Moreover, immunohistological studies showed enhanced expression of transforming growth factor-beta 1 (TGF-beta 1) in the injured glomeruli. Both drugs inhibited these adverse changes in the early phase. In the late phase, the progressive proteinuria, interstitial MNC infiltration were attenuated by both drugs. However, candesartan cilexetil significantly inhibited the progression of glomerulosclerosis, the expression of TGF-beta 1 and the interstitial fibrosis, while enalapril did not. Candesartan cilexetil and enalapril showed comparable hypotensive effects after the 16-week administration. These results indicate that candesartan cilexetil shows a more potent protective effect than enalapril against the progression of renal injury in the late phase. Thus, an AT1A might be more useful than an ACEI for the treatment of patients with chronic renal failure.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Disease Progression; Enalapril; Fibrosis; Glomerular Filtration Rate; Glomerulosclerosis, Focal Segmental; Kidney Failure, Chronic; Male; Nephrectomy; Proteinuria; Rats; Rats, Sprague-Dawley; Tetrazoles; Transforming Growth Factor beta

TCV-116 and enalapril were given in two stages: (early phase) for 6 to 10 weeks to 5/6 nephrectomized (NX) rats two weeks after nephrectomy, 12-week-old Wistar fatty (WF) rats and 7-week-old spontaneously hypercholesterolemic (SHC) rats; and (late phase) for 6 to 16 weeks to 5/6 NX rats 11 weeks after nephrectomy, 27-week-old WF rats and 10-week-old SHC rats. Urinary albumin, blood pressure (BP), glomerular filtration rate (GFR) and renal histology were examined. In the early phase, both agents inhibited proteinuria and tended to inhibit glomerulosclerosis. TCV-116 also inhibited interstitial inflammation. The antiproteinuric effects did not necessarily correlate with the BP-lowering effects. In the late phase, both agents showed equal antiproteinuric and antihypertensive effects. In 5/6NX and WF rats, TCV-116 inhibited tubulointerstitial inflammation/fibrosis, glomerulosclerosis and renal dysfunction, but enalapril had little effect on these parameters. In the SHC rats, TCV-116 inhibited renal tubulointerstitial inflammation and glomerulosclerosis, but enalapril inhibited only glomerulosclerosis. After drug administration, there was a positive correlation between proteinuria and BP, and a negative correlation between the severity of tissue damage and GFR, but not BP. These findings suggest that initial BP-independent tubulointerstitial inflammation may enhance glomerulosclerosis in the late phase, and TCV-116 might prevent the development of glomerulosclerosis through inhibition of angiotensin II-mediated tubulointerstitial damage in these models.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Diabetes Mellitus, Type 2; Enalapril; Glomerular Filtration Rate; Glomerulonephritis; Hypercholesterolemia; Kidney Glomerulus; Nephritis, Interstitial; Prodrugs; Proteinuria; Rats; Rats, Wistar; Tetrazoles

Blood pressure and heart rate were measured by telemetry in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) to investigate the contribution of angiotensin II to the reflex tachycardia resulting from exaggerated hypotension caused by a high dose of a calcium channel blocker. Pre-treatment with TCV-116, an angiotensin II AT1 receptor antagonist, or enalapril partially attenuated the reflex tachycardia induced by manidipine, but TCV-116 had almost no effect on the sinus tachycardia induced by isoproterenol. The suppressive effects of TCV-116 against the reflex tachycardia tended to be more obvious in WKY than in SHR, though the difference was not statistically significant. Concurrent administration of propranolol almost completely inhibited both the reflex tachycardia and the sinus tachycardia in SHR and WKY, indicating that the sympathetic nervous system contributes to both types of tachycardia. We demonstrated that angiotensin II may be involved in the reflex tachycardia induced by calcium channel blockers probably via activation of some component of the sympathetic nervous system other than postsynaptic factors at the sinus node.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Calcium Channel Blockers; Dihydropyridines; Enalapril; Hemodynamics; Hypotension; Nitrobenzenes; Piperazines; Propranolol; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Reflex; Tachycardia; Tachycardia, Sinus; Telemetry; Tetrazoles; Time Factors

Antihypertensive effects of an angiotensin (Ang) II receptor antagonist, candesartan cilexetil (TCV-116), were compared with those of an angiotensin converting enzyme (ACE) inhibitor, enalapril, in spontaneously hypertensive rats (SHR), 2-kidney, 1-clip hypertensive rats (2K, 1C-HR) and 1-kidney, 1-clip hypertensive rats (1K, 1C-HR). CV-11974, the active form of TCV-116, had no inhibitory activity for plasma ACE. In rats, TCV-116 inhibited the pressor responses to Ang I, Ang II, and Ang III without an effect on the bradykinin (BK)-induced depressor response. Enalapril inhibited only the Ang I-response and potentiated the BK-response. In SHR, the antihypertensive effect of TCV-116 (10 mg/kg) was larger than the maximum antihypertensive effect of enalapril and was not intensified by combination with enalapril. Administration of CV-11974 potentiated the maximum antihypertensive effect of enalapril. Although both agents reduced blood pressure in 2K, 1C-HR, only TCV-116 had a marked antihypertensive effect in 1K, 1C-HR. These findings indicate that TCV-116 is more effective than enalapril in reducing blood pressure in SHR and 1K, 1C-HR, and that the BK- and/or prostaglandin-potentiating effect of enalapril contributes little to its antihypertensive mechanism in SHR.

Topics: Administration, Oral; Angiotensin I; Angiotensin II; Angiotensin III; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Bradykinin; Enalapril; Enzyme Activation; Hypertension, Renal; Male; Peptidyl-Dipeptidase A; Rats; Rats, Inbred SHR; Rats, Sprague-Dawley; Rats, Wistar; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Renal Artery; Surgical Instruments; Tetrazoles; Vasoconstrictor Agents

The effects of TCV-116, a new non-peptide angiotensin II receptor antagonist, on systemic and renal hemodynamics were studied in conscious normotensive and renal hypertensive (2-kidney, 1-clip Gold-blatt type) dogs. When orally administered at 0.03 to 1.0 mg/kg, TCV-116 inhibited the pressor response to angiotensin II in conscious normotensive dogs in a dose-dependent fashion. The IC50 and IC100 values were 0.06 mg/kg and 0.86 mg/kg, respectively. TCV-116 at doses of 0.3 mg/kg and 1.0 mg/kg dose-dependently and persistently decreased systolic and diastolic blood pressure in both dogs with acute renal (hyperreninemic) and those with chronic renal (normoreninemic) hypertension. Even a high dose of TCV-116 (10 mg/kg, p.o.) increased effective renal plasma flow without affecting blood pressure or glomerular filtration rate in normotensive dogs. Furthermore, even at this high dose, TCV-116 did not reduce effective renal plasma flow or glomerular filtration rate in dogs with renal hypertension despite marked reduction in systemic blood pressure. The angiotensin converting enzyme inhibitor enalapril (10 mg/kg, p.o.) had renal hemodynamic effects similar to those of TCV-116. These findings indicate that TCV-116 has potent hypotensive effects not only in dogs with acute renal hypertension but also in those with chronic renal hypertension, but does not appear to adversely affect renal hemodynamics.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Dogs; Dose-Response Relationship, Drug; Enalapril; Heart Rate; Hemodynamics; Hypertension, Renal; Kidney Function Tests; Male; Renal Circulation; Renin; Tetrazoles

TCV-116 [(+/-)-(cyclohexyloxycarbony-loxy)ethyl2-ethoxy-1-[[2' -(1H- tetrazol-5-yl)biphenyl-4-yl]methyl]-1H-benzimidazole-7-carboxylate ], a nonpeptide selective angiotensin II type I receptor (AT1 receptor) antagonist, at the dose of 0.1, 1 or 10 mg kg-1 day-1, was orally given to 22-week-old stroke-prone spontaneously hypertensive rats (SHRSP) for 10 weeks (from the age of 22-32 weeks) to examine the effects on gene expression of transforming growth factor-beta 1 (TGF-beta 1) and extracellular matrix proteins in the heart and blood vessels. Tissue messenger RNA (mRNA) was measured by northern blot analysis, with a specific complementary DNA probe. In the heart, left ventricular mRNA levels for fibronectin; types I, III and IV collagen; and laminin were significantly higher in SHRSP than control Wistar-Kyoto rats. In the mesenteric artery and aorta of SHRSP, TGF-beta 1 mRNA and the mentioned extracellular matrix protein mRNAs were increased compared with Wistar-Kyoto rats. Thus, the expression of various genes was up-regulated in cardiovascular tissues of SHRSP. Treatment of SHRSP with TCV-116 suppressed the gene expression of the mentioned extracellular matrix proteins and TGF-beta 1 in both heart and blood vessels in a dose-dependent fashion. Furthermore, TCV-116 regressed cardiac hypertrophy and lessened the medial hypertrophy of the aorta in SHRSP. These results show that angiotensin AT1 receptor antagonist in vivo can inhibit the gene expression of TGF-beta 1 and extracellular matrix proteins in hypertensive cardiovascular tissues. These effects may contribute to the beneficial effects of AT1 receptor antagonist on hypertensive cardiac hypertrophy and vascular thickening.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Animals; Aorta; Benzimidazoles; Biphenyl Compounds; Cardiomegaly; Enalapril; Extracellular Matrix Proteins; Gene Expression Regulation; Hypertension; Male; Mesenteric Arteries; Myocardium; Rats; Rats, Inbred SHR; Rats, Inbred WKY; RNA, Messenger; Tetrazoles; Transforming Growth Factor beta

To study the effects of blockade of the renin-angiotensin system on the development of hypertension and end-organ damage in hyporeninaemic deoxycorticosterone acetate (DOCA)-salt hypertensive rats, using an angiotensin II (Ang II) receptor antagonist (TCV-116) or an angiotensin converting enzyme (ACE) inhibitor (enalapril).. DOCA-salt hypertensive rats were produced by uninephrectomy, implantation with DOCA pellets and 1% NaCl loading. TCV-116 (0.1 or 1 mg/kg) or enalapril (10 mg/kg) was given orally once a day from 3 to 6 weeks after the operation. Body weight, blood pressure, plasma renin and creatinine, urinary protein and blood urea nitrogen were measured. After 3 weeks' treatment, oedema and omega 3-subtype benzodiazepine receptor binding in the brain were measured.. Three weeks after the operation the blood pressure in the DOCA-salt hypertensive rats was approximately 200 mmHg, and the plasma renin concentration was lower than in sham-operated rats. However, after a further 3 weeks the renin concentration was slightly above the normal level, and this increase was accompanied by a decrease in body weight and increases in blood urea nitrogen, plasma creatinine, urinary protein and omega 3-subtype benzodiazepine receptor binding in the cerebral cortex, and by brain oedema. Treatment with TCV-116 or enalapril prevented renal damage and decrease in body weight with little effect on blood pressure. Enalapril prevented brain oedema and the increase in benzodiazepine binding in the brain cortex, and 1 mg/kg TCV-116 prevented them markedly.. Although the hypertension in DOCA-salt hypertensive rats is independent of the renin-angiotensin system, the degree of cerebral and renal damage is associated with the activity of the renin-angiotensin system and has little relationship with the blood pressure level.

Topics: Administration, Oral; Angiotensin II; Angiotensin Receptor Antagonists; Animals; Benzimidazoles; Biphenyl Compounds; Brain; Desoxycorticosterone; Disease Models, Animal; Enalapril; Hypertension; Kidney; Male; Rats; Rats, Wistar; Receptors, GABA-A; Renin-Angiotensin System; Sodium Chloride; Tetrazoles

To investigate the role of the renin-angiotensin system (RAS) on nephrosclerosis in salt-loaded, partially nephrectomized spontaneously hypertensive rats (SHR), we evaluated the effects of angiotensin II (ANGII) blockade on the progression of nephrosclerosis with an angiotensin type 1 receptor (AT1rec) antagonist [TCV-116 (TCV)] and an angiotensin-converting enzyme (ACE) inhibitor (enalapril) at the doses equivalent in reducing systemic blood pressure (BP). SHR were five/sixths nephrectomized and were fed a high-salt diet. In addition to being significantly preventive against an increase in systolic BP, both TCV and enalapril significantly attenuated the increases in proteinuria and the renal histopathological alterations. Transcription of AT1rec mRNA in the remnant kidney was enhanced with the progression of nephrosclerosis, but was inhibited by TCV as well as enalapril. In these aspects, there were no apparent differences between effects of TCV and enalapril. The RAS system plays an important role in nephrosclerosis in partially nephrectomized SHR despite a high-salt diet, and direct ANGII blockade certainly protected the kidney against hypertensive injury in this model.

Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Blotting, Northern; Body Weight; Enalapril; Hypertension; Kidney; Male; Nephrectomy; Nephrosclerosis; Proteinuria; Rats; Rats, Inbred SHR; Receptors, Angiotensin; Renin-Angiotensin System; RNA, Messenger; Sodium, Dietary; Tetrazoles; Transcription, Genetic

Recent evidence indicates that transforming growth factor-beta 1 (TGF-beta 1) plays an important role in renal fibrosis via stimulation of extracellular matrix synthesis. The present study was undertaken to investigate the role of angiotensin II type I receptor (AT1 receptor) in hypertension-induced renal injury. Twenty-two-week-old stroke-prone spontaneously hypertensive rats (SHRSP), which had established hypertension and moderate renal damage, were orally given TCV-116, a selective non-peptide AT1 receptor antagonist (0.1, 1 or 10 mg/kg/day), enalapril (10 mg/kg/day) or vehicle once a day for 10 weeks. At the end point of the treatment, we examined renal function, the gene expressions of TGF-beta 1 and extracellular matrix components in the interstitium [collagen types I (COI) and III (COIII), fibronectin (FN)] and the basement membrane (COIV and laminin), and renal microscopic morphology in rats aged 32 weeks. In vehicle-treated 32 week-old SHRSP with renal dysfunction and nephrosclerosis, renal mRNA levels for TGF-beta 1, COI, COIII, FN, COIV were all several-fold higher than in WKY. Thus, renal TGF-beta 1 gene expression was enhanced in SHRSP, which may contribute to the increased renal expressions of COI, COIII, FN, COIV in SHRSP. Treatment with TCV-116 (0.1 mg/kg/day) in SHRSP, in spite of no reduction of blood pressure, decreased renal mRNA levels for TGF-beta 1, COI, COIII, FN, COIV, being accompanied by the significant decrease in urinary protein and albumin excretion, blood urea nitrogen and plasma creatinine. Treatment with TCV-116 (10 mg/kg/day) in SHRSP decreased mRNAs for TGF-beta 1, COI, COIII, FN and COIV to almost the same levels as WKY, being associated with normalization of urinary protein and albumin excretion and the prevention of nephrosclerosis, as judged by microscopic histological observations. On the other hand, the effects of enalapril (10 mg/kg/day) on the above mentioned mRNA levels, renal function and renal morphology were weaker than those of TCV-116 (10 mg/kg/day) and were as much as TCV-116 (1 mg/kg/day). These results suggest that independently of hypotensive action, AT1 receptor antagonist has a potent renal protective effect by inhibiting the gene expression of renal TGF-beta 1 and extracellular matrix components.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Animals; Benzimidazoles; Biphenyl Compounds; Enalapril; Extracellular Matrix Proteins; Gene Expression; Hemodynamics; Hypertension; Kidney; Male; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Receptors, Angiotensin; RNA, Messenger; Tetrazoles; Transforming Growth Factor beta

To investigate the role of angiotensin II (Ang II) in hypertension-induced tissue injury, we gave TCV-116 (1 mg/kg per day PO), a nonpeptide Ang II type I receptor antagonist, or enalapril (10 mg/kg per day PO) to deoxycorticosterone acetate (DOCA)-salt hypertensive rats for 3 weeks and examined the effects on tissue mRNA levels for transforming growth factor-beta 1 (TGF-beta 1) and extracellular matrix components. Tissue mRNA levels were measured by Northern blot analysis. Renal mRNA levels for TGF-beta 1; types I, III, and IV collagen; and fibronectin in DOCA-salt hypertensive rats were increased by severalfold (P < .01) compared with sham-operated rats. In the aorta of DOCA-salt hypertensive rats, TGF-beta 1 and fibronectin mRNA levels were increased, but types I, III, and IV collagen mRNAs did not increase. In the heart, increased mRNA was found only for fibronectin. Thus, these gene expressions are regulated in a tissue-specific manner. TCV-116 or enalapril did not lower blood pressure in DOCA-salt hypertensive rats. However, the increase in renal mRNAs for TGF-beta 1 and extracellular matrix components in DOCA-salt hypertensive rats was significantly inhibited by treatment with TCV-116 or enalapril, which was associated with a significant decrease in urinary protein and albumin excretions and histological improvement of renal lesions. In contrast, in the aorta and heart these gene expressions were not affected by TCV-116 or enalapril. Thus, local Ang II may contribute to renal injury of DOCA-salt hypertension by stimulating the gene expression of TGF-beta 1 and extracellular matrix components.

Topics: Angiotensin II; Animals; Benzimidazoles; Biphenyl Compounds; Collagen; Desoxycorticosterone; Enalapril; Hypertension; Kidney; Kidney Diseases; Male; Organ Size; Rats; Rats, Wistar; Renin; RNA, Messenger; Sodium Chloride; Tetrazoles; Transforming Growth Factor beta