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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

TGR(mREN2)27 is a transgenic rat harboring the murine Ren-2 gene and exhibit fulminant hypertension and marked heart hypertrophy. In order to study the role of angiotensin II in the increase of cardiac mass, these animals were treated with antihypertensive and non-antihypertensive doses of the angiotensin II receptor AT1 antagonist Telmisartan for 9 weeks. All doses led to significant reductions of heart hypertrophy detected by the evaluation of the diameter of cardiac muscle bundles. We conclude from this study that cardiac hypertrophy in TGR(mREN2)27 is characterized by an increased volume of cardiomyocytes and an unchanged amount of fibrous tissue and that angiotensin II plays an important role in the mechanisms leading to this phenotype.
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PMID:Reduction of cardiac hypertrophy in TGR(mREN2)27 by angiotensin II receptor blockade. 897 60

1. A set-up for computerized acquisition and evaluation of haemodynamic data was constructed. Blood flow (BF) in the superior mesenteric and femoral artery of urethane-anaesthetized rats was measured with the ultrasonic transit time shift technique. The signals for arterial blood pressure and BF were fed into a personal computer via an analogue-digital converter. Mean arterial blood pressure, heart rate and vascular conductance (CV) were calculated on-line. For subsequent analysis of the data, algorithms were programmed to filter the data, and to determine average and peak values for each parameter. 2. Systemic hypertension induced by phenylephrine (3-300 nmol kg-1), angiotensin II (0.1-3.0 nmol kg-1) and arginine vasopressin (0.03-1.0 nmol kg-1) was accompanied by constriction of the mesenteric artery. In contrast, the femoral artery responded to phenylephrine with constriction, to angiotensin II with dilatation and to arginine vasopressin with dilation followed by constriction. The haemodynamic effects of endothelin-1 (0.03-3.0 nmol kg-1) were generally biphasic, the initial hypotension being associated with dilatation, and the delayed hypertension being accompanied by constriction of both the mesenteric and femoral arterial bed. 3. Terbutaline (3-1.0 nmol kg-1) and calcitonin gene-related peptide (0.03-1 nmol kg-1) caused systemic hypotension along with mesenteric and femoral vasodilatation. 4. Telmisartan (1 mg kg-1), an angiotensin AT1 receptor antagonist, dilated the mesenteric artery, but had no effect on femoral VC. In contrast, the alpha 1-adrenoceptor antagonist prazosin (0.1 mg kg-1), dilated the femoral artery without altering mesenteric VC. Similarly, the beta-adrenoceptor antagonist propranolol (1 mg kg-1) had no effect on mesenteric VC, but constricted the femoral arterial bed. 5. These data demonstrate that the haemodynamic effects of exogenously administered drugs can widely differ between the mesenteric and femoral arterial beds of urethane-anaesthetized rats. Furthermore, vascular tone of these two arterial beds in maintained by different vasoconstrictor systems. While the femoral artery is mainly under adrenergic control, the renin-angiotensin axis is predominant in the mesenteric arterial bed. In addition, this study also demonstrates that computerized analysis enables quick and accurate estimation of haemodynamic drug effects, and is superior to 'by hand' evaluation of peak changes in the functional diameter of the vascular bed under study.
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PMID:Differential regulation of mesenteric and femoral blood flow in the rat as revealed by computerized data acquisition and evaluation. 972 24

Telmisartan is a nonpeptide angiotensin II receptor antagonist which selectively and insurmountably inhibits the angiotensin II AT1 receptor subtype without affecting other receptor systems involved in cardiovascular regulation. Oral telmisartan dose-dependently reduced blood pressure (BP) in various animal models of hypertension. In transgenic rats, telmisartan reduced cardiac hypertrophy and glomerulosclerosis. When administered at dosages of 40 to 160 mg once daily to patients with mild to moderate hypertension, telmisartan significantly reduced systolic and diastolic BP compared with placebo and was at least as effective as atenolol 50 or 100 mg and lisinopril 10 to 40 mg. One study showed telmisartan 80 mg/day to be more effective than enalapril 20 mg/day. In 2 studies that used ambulatory BP monitoring, once daily telmisartan provided better control of diastolic BP for the full dosing interval than losartan potassium 50 mg or amlodipine 5 or 10 mg. In a single study in patients with severe hypertension, a telmisartan-based regimen had antihypertensive efficacy similar to that of an enalapril-based regimen. Telmisartan had a tolerability profile similar to that of placebo in clinical studies.
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PMID:Telmisartan. 987 91

OBJECTIVES: To compare the antihypertensive effects and duration of action of the angiotensin II receptor antagonist, telmisartan, amlodipine, and placebo in patients with mild-to-moderate hypertension using both conventional clinic blood pressures and ambulatory blood pressure monitoring (ABPM). METHODS: After a 4-week single-blind, placebo run-in period, qualifying patients were randomly allocated in double-blind manner to be administered 40 mg telmisartan (n = 73; increased to 80 and 120 mg as necessary for patients whose diastolic blood pressure (DBP) remained > 90 mmHg); 5 mg amlodipine (n = 78; titrated to 5 mg and titrated to 10 mg for patients whose DBP remained > 90 mmHg); or placebo (n = 81). ABPM was performed at the end of the baseline period and again at the end of 12 weeks of double-blind treatment. RESULTS: Telmisartan and amlodipine treatments significantly decreased trough supine systolic blood pressure and DBP (P < 0.001, measured conventionally) to a similar extent (by 13.1/7.1 and 14.0/7.1 mmHg, respectively, at the end of 12 weeks' treatment) compared with placebo. Both drugs also significantly reduced 24 h mean systolic blood pressures and DBP compared with placebo (P < 0.0001), measured using ABPM, maintaining control of blood pressure throughout the dosing period. Reductions in DBP with telmisartan were greater (P < 0.05) than those with amlodipine during the night-time interval and the last 4 h of the dosing period. Twenty-four-hour mean ABPM DBP < 85 mmHg were observed in 71% of telmisartan patients and in 55% of patients administered amlodipine. In addition, heart rates in patients treated with telmisartan were lower than heart rates in those treated with amlodipine during the final 4 h of the dosing period (P = 0.0003) and during the morning interval (P = 0.005). Generally, both telmisartan and amlodipine were well tolerated, however, drug-related edema occurred significantly more commonly (P < 0.05) among the patients administered amlodipine than it did among patients administered either telmisartan or placebo. CONCLUSIONS: Clinic blood pressure measurements detected no difference between the antihypertensive effects and durations of action of telmisartan and amlodipine, both agents producing statistically significant reductions compared with placebo. ABPM measurements, however, revealed differences between the efficacies at specific time points within the dosing periods. These findings highlight the potential importance of the use of ABPM for evaluating and comparing efficacies of antihypertensive agents.
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PMID:A comparison of the efficacies and duration of action of the angiotensin II receptor blockers telmisartan and amlodipine. 1021 69

Acceptance of the notion that physiologically specific interruption of the renin-angiotensin-aldosterone system (RAAS) is of considerable therapeutic benefit in the treatment of hypertension and congestive heart failure has generated great interest in the search for novel pharmacological inhibitors. The RAAS is expressed at the whole body, organ/tissue and cellular level through the action of the octapeptide angiotensin II (Ang II), the primary effector molecule of the RAAS. The availability of selective, potent, orally active and long-acting nonpeptide Ang II type 1 (AT1) receptor antagonists provided the opportunity to obtain the benefits of selectively blocking the RAAS at the level of the AT1 receptor that mediates most, if not all, of the important actions of Ang II, and avoid the nonspecificity of the Ang I converting enzyme (ACE) inhibitors. Losartan was the first, but by no means remained the only nonpeptide AT1 receptor antagonist. Numerous other "sartans" have emerged in the past several years and successfully completed clinical development. With the exception of Eprosartan, all others, i.e. Candesartan, Irbesartan, Saprisartan, Tasosartan, Telmisartan, Valsartan and Zolasartan, are based on modifications of Losartan's prototypic chemical structure. AT1 receptor antagonists represent the newest addition to the arsenal of cardiovascular therapeutics. The predominant role of the AT1 receptor in mediating the pathophysiological role of Ang II underlies the effectiveness of this novel class of agents to lower arterial blood pressure, reduce pre- and afterload, inhibit sympathetic nervous system activity and prevent cardiovascular hypertrophy and cardiac failure induced by inappropriate control of the RAAS.
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PMID:Angiotensin II receptor antagonists: an emerging new class of cardiovascular therapeutics. 1048 32

The antihypertensive efficacy and tolerability profiles of the selective AT1 receptor antagonists telmisartan and losartan were compared with placebo in a 6-week, multinational, multicentre, randomised, double-blind, double-dummy, parallel-group study of 223 patients with mild-to-moderate hypertension, defined as clinic diastolic blood pressure (DBP) >/=95 and </=114 mm Hg, clinic systolic blood pressure (SBP) >/=140 and </=200 mm Hg, and 24-h ambulatory DBP >/=85 mm Hg. After a 4-week single-blind placebo run-in, eligible patients were randomised to receive telmisartan 40 mg, telmisartan 80 mg, losartan 50 mg, or placebo. Ambulatory blood pressure monitoring (ABPM) after 6 weeks of double-blind therapy showed that all active treatments produced significant (P < 0.01) reductions from baseline in 24-h mean SBP and DBP compared with placebo. During the 18-to-24 h period after dosing, the reductions in SBP/DBP with telmisartan 40 mg (10.7/6.8 mm Hg) and 80 mg (12.2/7. 1 mm Hg) were each significantly (P <0.05) greater than those observed for losartan 50 mg (6.0/3.7 mm Hg), and losartan was no better than placebo. Also for the 24-h mean blood pressure, telmisartan 40 mg and 80 mg were significantly (P< 0.05) better than losartan 50 mg. Compared with losartan, telmisartan 80 mg produced significantly (P < 0.05) greater reductions in both SBP and DBP during all monitored periods of the 24-h period, while telmisartan 40 mg produced significantly greater reductions in SBP and DBP in the night-time period (10.01 pm to 5.59 am) (P < 0.05) and in DBP in the morning period (6.00 am to 11.59 am) (P < 0.05). All treatments were comparably well tolerated. Telmisartan 40 mg and 80 mg once daily were effective and well tolerated in the treatment of mild-to-moderate hypertension, producing sustained 24-h blood pressure control which compared favourably with losartan.
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PMID:ABPM comparison of the antihypertensive profiles of the selective angiotensin II receptor antagonists telmisartan and losartan in patients with mild-to-moderate hypertension. 1051 32

This 8-week, open-label study compared the efficacy and safety of once-daily telmisartan, either alone or in combination with hydrochlorothiazide (HCTZ) and amlodipine, with a similar enalapril regimen in patients with severe hypertension. Clinically relevant reductions in supine systolic blood pressure/DBP were observed with telmisartan (14.6/13.2 mmHg) and enalapril (13.0/12.9 mmHg) monotherapy. Incremental reductions were seen with up-titration of monotherapy (telmisartan 8.1/7.4 and enalapril 9.2/7.7 mmHg), and the addition of HCTZ (telmisartan 14.9/8.7 and enalapril 8.0/6.7 mmHg), and amlodipine (telmisartan 8.0/6.5 and enalapril 10.5/6.4). After 8 weeks of treatment, supine DBP control was achieved in 55% and 35% of the patients on the telmisartan and enalapril regimens, respectively. Both treatment regimens were well tolerated. Telmisartan, a new angiotensin receptor blocker, is a safe and effective drug to use in combination for the treatment of patients with severe hypertension and proved at least as effective as the enalapril combination.
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PMID:The efficacy and safety of telmisartan compared to enalapril in patients with severe hypertension. 1066 27

Telmisartan (Micardis (R)) is a new, orally active, long-acting angio-tensin (Ang) II receptor antagonist that is effective in the treatment of hypertension. Ambulatory blood pressure monitoring (ABPM) has emerged as an important method for evaluating the consistency of the antihypertensive effects of a drug throughout the dosing interval. ABPM was used to evaluate the antihypertensive efficacy of telmisartan in several placebo-controlled, double-blind, multicenter studies. Patients with mild-to-moderate hypertension were allocated randomly to groups to receive telmisartan 40 or 80 mg, losartan 50 mg, or placebo, once daily in a 6-week, fixed-dose study, or telmisartan 40-120 mg, amlodipine 5-10 mg, or placebo, once daily in a 12-week, dose-titration study. Patients treated with telmisartan 40 and 80 mg or placebo in a separate 4-week, fixed-dose study were included in an additional analysis. Telmisartan 40 and 80 mg significantly decreased mean ambulatory systolic blood pressure (SBP) and diastolic blood pressure (DBP) relative to placebo for the entire 24 h period and in the following intervals: day (6 a.m. to 10 p.m.), morning (6 a.m. to noon), night (10 p.m. to 6 a.m), and the last 4 h of the dosing interval (P<0.01). Notably, telmisartan 40 or 80 mg was more effective than losartan, especially during the last 4-6 h of the dosing interval (P<0.05). Telmisartan 40- 120 mg tended to be more effective than amlodipine 5-10 mg in reducing SBP and DBP in each time interval, with significant differences between treatments noted for DBP in the last 4 h of the dosing interval and in the morning (P < 0.05). ABPM also revealed that the magnitude of the blood pressure decreasing effect with telmisartan was consistent throughout the dosing interval. These results demonstrate that telmisartan maintains a normal circadian blood pressure pattern and provides full 24 h blood pressure control with once-daily dosing.
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PMID:Use of ambulatory blood pressure monitoring to evaluate the selective angiotensin II receptor antagonist, telmisartan, and other antihypertensive drugs. 1090 41

Diabetic nephropathy, which develops in about 30% of patients with diabetes, is a progressive condition. It is characterized by increased blood pressure, declining glomerular filtration rate and albuminuria. Lowering of blood pressure in diabetic patients is associated with reduced cardiovascular risk and renal protection. Inhibitors of angiotensin-converting enzyme (ACE) are the current gold standard treatment for hypertension in patients with type I diabetes because, in addition to their blood pressure lowering ability, they are thought to oppose the increased intraglomerular pressure that is mediated in part by angiotensin II. The angiotensin II receptor antagonists, a more recently developed class of antihypertensive agents, appear to be as effective as ACE inhibitors in delaying the progression of renal injury in animal models of diabetes. They act by selectively blocking the binding of angiotensin II to the AT1 receptor and may, therefore, offer a more complete blockade of the renin-angiotensin system than ACE inhibitors. The renal and antihypertensive effects of this class of drug in patients with diabetes are now being investigated in long-term clinical trials. The multicentre Diabetics Exposed to Telmisartan And EnalaprIL (DETAIL) study is a randomized, double-blind, parallel-group comparison of the renal and antihypertensive effects of the angiotensin II receptor antagonist telmisartan and the ACE inhibitor enalapril in 272 patients with type II diabetes. The primary outcome is change in glomerular filtration rate over the 5 years of the study.
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PMID:The role of angiotensin II receptor antagonists in the management of diabetes. 1133 10

Several orally active non-peptide angiotensin II subtype 1 (AT1) receptor antagonists are now available for the treatment of hypertension. These agents have a common mechanism of action--blockade of the binding of angiotensin II to the subtype 1 receptor--and their binding to this receptor is generally insurmountable. There are some pharmacokinetic and pharmacodynamic differences between these antagonists, which may reflect in their clinical efficacy, especially at the end of the dosing interval. Losartan has an active metabolite that prolongs its duration of action, and candesartan cilexetil requires conversion to an active form after administration. Telmisartan has the longest duration of action, with a terminal elimination half-life of around 24 h in comparison with 11-15 h for irbesartan, the agent with the next longest half-life. The long duration of action and insurmountable binding to the receptor may be related to the slow dissociation kinetics of the antagonists from the AT1 receptor. Comparative clinical studies suggest that at the recommended dose losartan, the original drug in this class, has a lower antihypertensive efficacy than the newer agents, such as telmisartan. It is possible that these differences between angiotensin II receptor antagonists are due to variations in the degree and duration of receptor blockade, and may be of clinical significance with regard to the cardioprotective and renoprotective effects of this class of antihypertensive agents.
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PMID:The comparative pharmacology of angiotensin II receptor antagonists. 1133 13


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