Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.15.1 (ACE)
18,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Renin is the main determinant of angiotensin (Ang) II levels. It, therefore, always appeared desirable to reduce Ang II levels by direct inhibition of renin. So far, specific renin inhibitors lacked potency and/or oral availability. We tested the new orally active nonpeptidic renin inhibitor SPP100 (Aliskiren, an octanamide with a 50% inhibitory concentration [IC50] in the low nanomolar range) in 18 healthy volunteers on a constant 100 mmol/d sodium diet using a double-blind, 3-way crossover protocol. In 3 periods of 8 days, separated by wash-outs of 6 days, each volunteer received 2 dosage levels of Aliskiren (low before high; 40 and 80 or 160 and 640 mg/d) and randomized placebo or 20 mg enalapril. Aliskiren was well tolerated. Not surprisingly, blood pressure and heart rate remained unchanged in these normotensive subjects. There was a dose-dependent decrease in plasma renin activity, Ang I, and Ang II following single doses of Aliskiren starting with 40 mg. Inhibition was still marked and significant after repeated dosing with maximal decreases in Ang II levels by 89% and 75% on Days 1 and 8, respectively, when the highest dose of Aliskiren was compared with placebo. At the same time, mean plasma active renin was increased 16- and 34-fold at the highest dose of Aliskiren. Plasma drug levels of Aliskiren were dose-dependent with maximal concentrations reached between 3 to 6 hours after administration; steady state was reached between 5 and 8 days after multiple dosing. Less than 1% of dose was excreted in the urine. Plasma and urinary aldosterone levels were decreased after doses of Aliskiren > or =80 mg and after enalapril. Aliskiren at 160 and 640 mg enhanced natriuresis on Day 1 by +45% and +62%, respectively, compared with placebo (100%, ie, 87+/-11 mmol/24h) and enalapril (+54%); kaliuresis remained unchanged. In conclusion, the renin inhibitor Aliskiren dose-dependently decreases Ang II levels in humans following oral administration. The effect is long-lasting and, at a dose of 160 mg, is equivalent to that of 20 mg enalapril. Aliskiren has the potential to become the first orally active renin inhibitor that provides a true alternative to ACE-inhibitors and Ang II receptor antagonists in therapy for hypertension and other cardiovascular and renal diseases.
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PMID:Angiotensin II suppression in humans by the orally active renin inhibitor Aliskiren (SPP100): comparison with enalapril. 1179 2

This editorial considers the use of the first selective oral renin inhibitor, aliskiren, in reducing angiotensin (Ang) II reactivation or aldosterone (ALDO) escape during renin-angiotensin-aldosterone system (RAAS) inhibition. RAAS blockade with angiotensin converting enzyme inhibitors (ACEIs) and/or angiotensin receptor AT(1) blockers (ARBs) is very useful for the treatment of arterial hypertension, chronic heart failure (CHF), atherosclerosis and diabetes. 'Ang II reactivation' and 'ALDO escape' or 'breakthrough' have been observed during either ACEI or ARB treatment, and may attenuate the clinical benefit of RAAS blockade. Renin and Ang I accumulate during ACE inhibition, and might overcome the ability of an ACEI to effectively suppress ACE activity. There is also data suggesting that 30 - 40% of Ang II formation in the healthy human during RAAS activation is formed via renin-dependent, but ACE-independent, pathways. Moreover, ACE gene polymorphisms contribute to the modulation and adequacy of the neurohormonal response to long-term ACE inhibition, at least in patients with CHF (up to 45% of CHF patients have elevated Ang II levels despite the long-term use of an ACEI) or diabetes. The reactivated Ang II promotes ALDO secretion and sodium reabsorption. ALDO breakthrough also occurs during long-term ARB therapy, mainly by an AT(2)-dependent mechanism. This was related to target-organ damage in animal models. Oral renin inhibition with aliskiren has showed excellent efficacy and safety in the treatment of hypertension. Aliskiren can be co-administered with ACEIs, ARBs or hydrochlorothiazide. Furthermore, there is evidence suggesting that aliskiren reduces Ang II reactivation in ACE inhibition and ALDO escape during treatment with an ACEI or an ARB, at least to the degree that this is associated with the RAAS. For RAAS-independent ALDO production, the combination of aliskiren with eplerenone might prove useful.
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PMID:Angiotensin II reactivation and aldosterone escape phenomena in renin-angiotensin-aldosterone system blockade: is oral renin inhibition the solution? 1737 10

Patients with severe hypertension (>180/110 mm Hg) require large blood pressure (BP) reductions to reach recommended treatment goals (<140/90 mm Hg) and usually require combination therapy to do so. This 8-week, multicenter, randomized, double-blind, parallel-group study compared the tolerability and antihypertensive efficacy of the novel direct renin inhibitor aliskiren with the angiotensin converting enzyme inhibitor lisinopril in patients with severe hypertension (mean sitting diastolic blood pressure (msDBP)>or=105 mm Hg and <120 mm Hg). In all, 183 patients were randomized (2:1) to aliskiren 150 mg (n=125) or lisinopril 20 mg (n=58) with dose titration (to aliskiren 300 mg or lisinopril 40 mg) and subsequent addition of hydrochlorothiazide (HCTZ) if additional BP control was required. Aliskiren-based treatment (ALI) was similar to lisinopril-based treatment (LIS) with respect to the proportion of patients reporting an adverse event (AE; ALI 32.8%; LIS 29.3%) or discontinuing treatment due to AEs (ALI 3.2%; LIS 3.4%). The most frequently reported AEs in both groups were headache, nasopharyngitis and dizziness. At end point, ALI showed similar mean reductions from baseline to LIS in msDBP (ALI -18.5 mm Hg vs LIS -20.1 mm Hg; mean treatment difference 1.7 mm Hg (95% confidence interval (CI) -1.0, 4.4)) and mean sitting systolic blood pressure (ALI -20.0 mm Hg vs LIS -22.3 mm Hg; mean treatment difference 2.8 mm Hg (95% CI -1.7, 7.4)). Responder rates (msDBP<90 mm Hg and/or reduction from baseline>or=10 mm Hg) were 81.5% with ALI and 87.9% with LIS. Approximately half of patients required the addition of HCTZ to achieve BP control (ALI 53.6%; LIS 44.8%). In conclusion, ALI alone, or in combination with HCTZ, exhibits similar tolerability and antihypertensive efficacy to LIS alone, or in combination with HCTZ, in patients with severe hypertension.
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PMID:A comparison of the tolerability of the direct renin inhibitor aliskiren and lisinopril in patients with severe hypertension. 1754 89

The renin-angiotensin-aldosterone system (RAAS) plays an important part in the pathogenesis of arterial hypertension and the complications it causes in organs (the heart, the circulatory system, the brain, the kidneys), heart failure and kidney diseases. Materials that block the most upstream point of the RAAS cascade (ACE inhibitors - ACEI, AT1,-receptor (AT1R) blockers, aldosterone receptor blockers) have greatly expanded our options in the treatment and primary and secondary prevention of cardiovascular and renal diseases. ACEI and AT1R blockers interrupt the normal feedback provided by the release of renin into the circulatory system from the kidneys. After they are applied the reactive increase in active circulating renin leads to increased creation of angiotensin I and angiotensin II and the subsequent return of aldosterone secretions to pre-treatment values ("escape" phenomenon). The possible negative effect of these intermediary products of an incomplete blockade of RAAS on organ complications lead to an effort to develop a material that could block the renin-angiotensin cascade at its first stage--i.e. a renin blocker. The first efforts with renin antibodies or peptide analogues of renin prosegments failed to satisify the basic requirements for long-term medication--effectiveness when used orally. In recent years the first non-peptidic, oral renin ihibitor providing sustained effects has been developed, aliskiren fumarate. Aliskiren reduces BP depending on the dose (50-300 mg/day) in monotherapy or in combination with hydrochlorothiazide. Aliskiren lowers plasma renin activity (PRA) and neutralises the activation of the RAAS triggered by hydrochlorothiazide. Ambulatory BP monitoring has shown that taking the medicine once a day has a 24-hour effect and its continued residence in the kidneys suggests renoprotective effects. The compound is in the third stage of clinical tests as a monotherapy or in combination for the treatment of hypertension. It has also been shown to have an influence on the regression of cardiac hypertrophy (Aliskiren in Left-Ventricular Hypertrophy trial - ALLAY), the treatment of heart failure (Aliskiren Observation of Heart Failure Treatment trial - ALOFT) and diabetic (Aliskiren in the Evaluation of Proteinuria in Diabetes trial - AVOID). In April 206, the FDA permitted the use of aliskiren in the USA for the treatment of high BP and it is currently undergoing testing in Europe. The renin inhibitor has minimal undesirable side effects, like AT1-receptor blockers. The slightly lower effectiveness ofaliskiren than AT1-receptor blockers in reducing BP is caused by the fact that it does not block bradykinins. It is recommended as a monotherapy for clinical use or in combination with other antihypertensive medicines for conditions with high levels of PRA including its rise after diuretics, ACEI and AT1-receptor blockers. Aliskiren could therefore be used primarily with young patients, Caucasians, persons with ACEI intolerance, and also in diseases where angiotensin II is involved in the pathogenesis and the secondary prevention of cardiovascular disease. It is also safe for persons with concurrent renal problems, because it is mainly removed by the liver without great interference with other materials. Like ACEI, the renin inhibitor has a vasodilatory effect which could potentially improve the elasticity of arteries. The medicine has the same limitations and contraindications as ACEI and AT1R blockers, such as pregnancy and bilateral renal artery stenosis. A definitive assessment of the benefit of this new class of medicines and its broad application in the treatment of cardiovascular and other diseases will require demonstration of its long-term effect on morbidity and mortality, as well as comparison with other RAAS blockers in long clinical studies, which represent research programmes lasting another 7 to 8 years.
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PMID:[Does the rennin inhibitor aliskiren offer promising novel opportunities in the treatment of cardiovascular diseases?]. 1757 67

Aliskiren, the direct renin inhibitor, is the first new class of drug available in 13 years for the treatment of hypertension. Renin has long been recognized as a preferred site for blockade of the renin-angiotensin-aldosterone system because it prevents conversion of angiotensinogen to angiotensin I. Aliskiren binds to the active site of the renin molecule, blocking angiotensinogen cleavage, thus, preventing the formation of angiotensin I. Clinical studies have demonstrated at least equivalent or superior blood pressure lowering efficacy compared with existing drugs with a favorable side effect profile. Aliskiren possesses possible synergistic potential when combined with a thiazide diuretic, ACE inhibitor, angiotensin receptor blocker and calcium channel blocker both in terms of efficacy and tolerability. This review aims to define the role of aliskiren in the therapeutic management of hypertension.
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PMID:Aliskiren, the first in a new class of direct renin inhibitors for hypertension: present and future perspectives. 1795 3

1. Initial attempts to inhibit renin in humans have faced numerous difficulties. Molecular modelling and X-ray crystallography of the active site of renin have led to the development of new orally active renin inhibitors, such as aliskiren. 2. Aliskiren has a low bioavailability (between 2.6 and 5.0%) compensated by its high potency to inhibit renin (IC50: 0.6 nmol/L) and a long plasma half-life (23-36 h), which makes it suitable for once-daily dosing. 3. The once-daily administration of aliskiren to hypertensive patients lowers BP as strongly as standard doses of established angiotensin II type 1 (AT1) receptor blockers (losartan, valsartan, irbesartan), hydrochlorothiazide, angiotensin converting enzyme inhibitors (ramipril and lisinopril) or long acting calcium channel blockers (amlodipine). In combination therapy, aliskiren further decreases blood pressure when combined with either hydrochlorothiazide, amlodipine, irbesartan or ramipril. 4. The biochemical consequences of renin inhibition differ from those of angiotensin I-converting enzyme (ACE) inhibition and Ang II antagonism, particularly in terms of angiotensin profiles and interactions with the bradykinin-nitric oxide-cyclic guanosine monophosphate pathway and possibly the (pro)renin receptor. 5. Blockade of the renin angiotensin system (RAS) with ACE inhibitors, AT1 receptor blockers or a combination of these drugs has become one of the most successful therapeutic approaches in medicine. However, it remains unclear how to optimize RAS blockade to maximize cardiovascular and renal benefits. In this context, renin inhibition to render the RAS fully quiescent is a new possibility requiring further study.
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PMID:Renin inhibition with aliskiren. 1830 34

The development of aliskiren, the first orally effective renin inhibitor, utilized molecular modeling based upon X-ray crystallographic analysis of renin's active site to design a potent, low molecular weight renin inhibitor with improved bioavailability (approximately 2.6%). In patients with hypertension, dose-dependent BP reduction occurs with aliskiren 75-300 mg once daily; at these doses, the safety and tolerability profile is comparable to placebo. In direct comparison studies, BP reduction with aliskiren is equivalent to commonly used antihypertensive agents including diuretics, ACE inhibitors, and ARBs. Persistent BP reduction and prolonged suppression of plasma renin activity (PRA) is observed after aliskiren withdrawal. Aliskiren suppresses PRA when given either as monotherapy or in combination with other agents. When added to an ARB, aliskiren blocks compensatory RAS activation and produces significant additional BP reduction. In patients with diabetic nephropathy, addition of aliskiren to losartan, 100 mg resulted in a 20% greater reduction in proteinuria. Ongoing studies evaluating the long-term renal protective effects of aliskiren and its effects on ventricular remodeling are currently planned or underway.
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PMID:Current concepts: renin inhibition in the treatment of hypertension. 1830 34

Initial attempts to inhibit renin in humans have faced numerous difficulties. Molecular modeling and X-ray crystallography of the active site of renin have led to the development of new orally active renin inhibitors such as aliskiren. Aliskiren has a low bioavailability (2.6% to 5%) compensated by its high potency to inhibit renin and a long plasma half-life (24 to 40 h), which makes it suitable for once-daily dosing. The once-daily administration of aliskiren to hypertensive patients lowers blood pressure as strongly as standard doses of established AT1 receptor blockers (losartan, valsartan, and irbesartan), angiotensin-converting enzyme inhibitors (ramipril and lisnopril), hydrochlorothiazide, or long-acting calcium channel blockers (amlodipine). In combination therapy, aliskiren further decreases blood pressure when combined with either hydrochlorothiazide, amlodipine, valsartan, irbesartan, or ramipril. However, the biochemical consequences of renin inhibition differ from those of angiotensin I-converting enzyme inhibition and angiotensin II antagonism, particularly in terms of angiotensin profiles and interactions with the bradykinin-NO-cGMP pathway. Blockade of the renin-angiotensin system with angiotensin I-converting enzyme inhibitors, AT1 receptor blockers, or a combination of these drugs has become one of the most successful therapeutic approaches in medicine. However, it remains unclear how to optimize renin-angiotensin system blockade to maximize cardiovascular and renal benefits. In this context, renin inhibition to render the renin-angiotensin system fully quiescent is a new possibility requiring further study. Preliminary results show that short-term administration of aliskiren has beneficial anti-albuminuric effects in diabetic patients with chronic nephropathy and favorable neurohormonal effects in patients with chronic heart failure.
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PMID:Direct renin inhibition: clinical pharmacology. 2223 43

Hypertension is one of the major risk factors for cardiovascular morbidity and mortality. Lowering blood pressure (BP) may reduce the risk of stroke by 40% and the risk of ischemic heart disease by 20%. Despite the varied drugs available to lower BP, more than 50% of the hypertensive patients are not well-controlled. The major reason for the failure to control BP is noncompliance which is related to the side effects and inconvenience of drug administration. Aliskiren, a new oral direct renin inhibitor is very effective in BP reduction. It is given once daily and has very few side effects, almost like a placebo. It is well combined with diuretics, angiotensin converting enzyme (ACE) inhibitors and calcium channel blockers. Unlike ACE inhibitors and angiotensin receptor blockers that block the renin angiotensin axis in its last part and thereby raise the rein-levels, the direct renin inhibitor block the renin-angiotensin axis in its beginning and keep the renin levels suppressed. Aliskiren is a promising agent but further prospective studies with morbidity and mortality data as endpoints are required, before the drug can be recommended as a first choice agent.
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PMID:[Is there a need for direct renin inhibitors?]. 1848 62

Hypertension is the most common risk factor for cardiovascular disease, constituting the most common cause of death in industrialized countries. Therefore, the task of blood pressure reduction has significant importance in reducing vascular damage, myocardial infarctions, kidney damage and incidence of cerebrovascular accidents. The renin-angiotensin-aldosterone system (RAAS) plays a central role in control and function of the cardiovascular and renal systems, and is deeply involved in the pathophysiology of diseases of vasculature, heart, kidneys and others. Therefore, blockade of RAAS by angiotensin converting enzyme (ACE) inhibitors and blockers of angiotensin II type AT1 receptors (ARBs) is widely utilized by clinicians. Indeed, it has long been known that ACE inhibitors and ARBs protect different targets of angiotensin II, due to impedance of the negative effects of the hormone and the inhibition of aldosterone production, which contributes both directly and indirectly to the damages, independent of angiotensin II. Despite this, the morbidity and mortality resulting from the progression of cardiovascular diseases in patients treated with ACE inhibitors or ARBs remain high. As such, over the years, much effort has been dedicated to the development of direct inhibitors of renin. The earliest renin inhibitors, developed 30 years ago were not effective due to their protein nature, which prevents their oral administration and limited their clinical use. In the last decade, several non-protein renin inhibitors which could be given orally were developed, of which Aliskiren is the most well known representative. Due to the fact that neutralization of the RAAS by ACE inhibitors and ARBs has been reviewed at length many times, this review will focus on the renewed subject of renin inhibition. The earliest research, both in humans as well as in animal models, show that Aliskiren has therapeutic potential in treatment of patients with hypertension, cardiovascular disease and renal disease. However, the efficacy of Aliskiren in treating systolic and diastolic hypertension in patients was not better than that obtained using ACE inhibitors or ARBs. Even so, there is no need to lower levels of optimism for potential therapy using direct inhibitors of renin. Current research is still in its early stages and there is a need to remember that it took many years to prove the clinical usefulness of ACE inhibitors, which are now central to treatment of cardiovascular and renal diseases, including hypertension.
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PMID:[Oral inhibitors of renin and their potential use as therapeutic agents in treating hypertension]. 1869 32


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