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)

The current revolution in the treatment of acute myocardial infarction by means of thrombolytic therapy has as its underlying strategy three aims: early restoration of the blood flow in order to salvage jeopardized but still viable tissues; limitation of acute consequences of ischemic heart disease, such as infarct size, ventricular fibrillation, and pericardial effusion; and preservation, as far as possible, of ventricular function. It is also hoped that these three achievements will result in reduced short- as well as long-term mortality rates. The techniques employed in this overall strategy are still under investigation, and several leading pharmacological compounds vie for supremacy: streptokinase (SK) and its anisoylated form (APSAC), recombinant technique tissue type plasminogen activator (rt-PA), and urokinase (UK) with or without prourokinase (PUK). Other pharmacological agents, such as angiotensin converting enzyme (ACE) inhibitors, beta-blockers, Ca2+ antagonists, and O2 radical scavengers, might find here their "finest hour" yet. In addition, the underlying anatomy may require early or, where needed, delayed PTCA, backed up by coronary artery bypass grafting. Thus, the tactics of the intervention may vary from case to case and indeed from center to center depending on experience and facilities, but the strategic conclusion is clearly the same: early reperfusion is a must if one wishes to save ischemic but still viable tissue.
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PMID:Acute consequences of ischemic myocardial damage. 248 24

Bradykinin (BK) is widely believed to play a role in the pathogenesis of anaphylaxis. To help clarify any such roles, we examined for effects of inhibitors of kininase II (angiotensin converting enzyme, ACE) and "kininase I" (carboxypeptidase N, CPN), on the early course of egg albumin-induced aggregate anaphylaxis in anesthetized guinea pigs. In this model, pulmonary and systemic arterial blood pressure (BP) rise (unless pulmonary fibrillation occurs), lung wgt increases by approximately 60% and pulmonary microvessels are occluded by cell-rich thrombi, all within 5 min of i.v. antigen. The 30 min mortality rate is approximately 2%. ACE inhibitors (BPP9a, Captopril and MK 422; doses up to 140 mumol/kg) do not make anaphylaxis more nor less severe in terms discernible by changes in BP, lung wgt, EKG or intravascular coagulation. In marked contrast, an inhibitor of CPN (2-mercaptomethyl-3-guanidinoethylthiopropionic acid, 2-MGP; 8-16 mumol/kg) increases the 30 min mortality rate to 94% and lung wgt to 180% of control. The animals die in ventricular fibrillation. Given the enormous BK potentiating effects of BPP9a, Captopril and MK 422, it seems likely that little if any BK is formed in the early min of anaphylaxis. 2-MGP does not potentiate BP effects of BK but markedly potentiates effects of C3a anaphylatoxin. Thus, our data support the views that BK is neither a primary nor secondary mediator of aggregate anaphylaxis, and the adverse effects of 2-MGP are best explained in terms of preservation of anaphylatoxins and not in terms of preservation of kinins.
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PMID:Aggregate anaphylaxis and carboxypeptidase N. 302 62

Theoretically, it should be possible to match the requirements of individual patients with the pharmacological and clinical properties of the large number of antihypertensive drugs now available. The concept of automatic sequential stepped-care therapy is now largely outdated, but therapy of clinically important hypertension must be initiated with one agent. Diuretics remain a first-line option in the elderly and in Black patients, as do calcium antagonists. Outcome trials are available only for the elderly, and in these the benefits of initial diuretic therapy are well documented. Nonetheless, diuretics may often need to be co-prescribed with a beta-blocker or an adrenergic modifier such as methyldopa. beta-Blockers are preferred in patients with ischaemic heart disease or enhanced adrenergic drive, while alpha-blockers are preferred in patients with blood lipid abnormalities or prostatic problems. Calcium antagonists or angiotensin converting enzyme (ACE) inhibitors are being increasingly used as initial therapy when quality of life is important and metabolic neutrality is required. Calcium antagonists are more likely to be effective first-line therapy than ACE inhibitors in patients with a high salt intake, in patients with Raynaud's disease, when angina pectoris is present, and in Black patients. ACE inhibitors are preferred for combination with diuretic agents, and in the presence of congestive heart failure or low salt intake. Experimentally, both calcium antagonists and ACE inhibitors can prevent ischaemic ventricular fibrillation and atheroma. Combination therapy between these 2 drug classes is gaining increasing acceptance because of these theoretical advantages.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Individualised selection of antihypertensive therapy. 751 67

Inhibition of the angiotensin converting enzyme (ACE) with ramipril was studied in male Wistar rats during long-term inhibition of nitric oxide (NO) synthase by NG-nitro-L-arginine methyl ester (L-NAME). Chronic treatment with L-NAME in a dose of 25 mg/kg per day over 6 weeks caused myocardial hypertrophy and a significant increase in systolic blood pressure (245 +/- 16 mmHg) as compared to controls (155 +/- 4 mmHg). Animals receiving simultaneously L-NAME and ramipril were protected against blood pressure increase and partially against myocardial hypertrophy. L-NAME caused a significant reduction in glomerular filtration rate (GFR: 2.56 +/- 0.73 ml.kg-1.min-1) and renal plasma flow (RPF: 6.93 +/- 1.70 ml.kg-1.min-1) as compared to control (GFR: 7.29 +/- 0.69, RPF: 21.36 +/- 2.33 ml.kg-1.min-1). Addition of ramipril prevented L-NAME-induced reduction in GFR and renal plasma flow. L-NAME produced an elevation in urinary protein excretion and serum creatinine and a decrease in potassium excretion which was antagonised by ramipril. L-NAME-induced increase in plasma renin activity (PRA) was further elevated with ramipril treatment. Isolated hearts from rats treated with L-NAME showed increased post-ischaemic reperfusion injuries. Compared to controls duration of ventricular fibrillation was increased and coronary flow reduced. During ischemia the cytosolic enzymes lactate dehydrogenase and creatine kinase, as well as lactate in the venous effluent were increased. Myocardial tissue values of glycogen, ATP, and creatine phosphate were decreased, whereas lactate was increased.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Ramipril prevents the detrimental sequels of chronic NO synthase inhibition in rats: hypertension, cardiac hypertrophy and renal insufficiency. 753 99

To delineate the cardioprotective actions of bradykinin (BK) and the contribution of endogenous kinins to the cardiac effects of the ACE inhibitor ramipril, we used the specific B2 kinin receptor antagonist icatibant (HOE 140) during myocardial ischemia and left ventricular hypertrophy (LVH). In isolated working rat hearts, perfusion with ramiprilat (10 nM to 10 microM) reduced the incidence and duration of ventricular fibrillation, and improved cardiodynamics and myocardial metabolism. BK perfusion (0.1 nM to 10 nM) induced comparable cardioprotective effects. In addition, perfusion with ramiprilat (0.1 microM) markedly increased kinin outflow measured by RIA. The beneficial effects of ramiprilat and BK were abolished by the addition of the specific NO synthase inhibitor NG-nitro-L-arginine (L-NNA 1 microM) or icatibant (1 nM). Similar results were obtained in dogs, rabbits and rats with myocardial infarction induced by ligation of the left descending coronary artery. The influence of the icatibant on the antihypertrophic effect of ramipril and BK in the LVH was investigated in rats made hypertensive by aortic banding. Ramipril at the antihypertensive dose of 1 mg kg-1 day-1 for 6 weeks prevented the increase in blood pressure and the development of LVH. The lower non-antihypertensive dose of ramipril (10 micrograms kg-1 day-1 for 6 weeks) had no effect on the increase in blood pressure or on plasma ACE activity but also prevented LVH after aortic banding. The antihypertrophic effect of the higher and the lower dose of ramipril as well as the antihypertensive action of the higher dose of ramipril were abolished by coadministration of the icatibant.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cardioprotective actions of bradykinin in myocardial ischemia and left ventricular hypertrophy. 774 86

From pharmacological investigations and clinical studies, it is known that ACE inhibitors exhibit additional local actions that are not related to hemodynamic changes and that cannot be explained only by interference with the renin-angiotensin system by means of an inhibition of ANG II formation. Because ACE is identical to kininase II, which inactivates the nonapeptide BK and related kinins, potentiation of kinins might be responsible for these additional effects of ACE inhibitors. ACE inhibition, concentration, and time dependently increased the formation of NO and PGI2 in cultured endothelial cells of different origin and from different species, including humans. The specific B2 kinin receptor antagonist, icatibant, suppressed the ACE inhibitor-induced increase in endothelial cyclic GMP accumulation index for NO-formation and, in parallel, attenuated the increase in PGI2 release. In renovascular models of hypertension associated with a stimulated renin-angiotensin system (two-kidney, one-clip), blood pressure reduction by ACE inhibitors was attenuated by icatibant, whereas in rats with genetic hypertension with normal to low plasma renin, blood pressure reduction through ACE inhibitors was not affected. In experimental atherosclerosis in rabbits, ACE inhibitors were able to preserve endothelial function and vascular reactivity and to reduce surface involvement. In the balloon denudation model of carotid arteries in rats, it was found that ACE inhibition markedly reduced neointima formation. However, when the ACE inhibitor was given together with icatibant, its effect was significantly blunted. Perfusion with ACE inhibitors induced a reduction of the incidence, as well as of the duration, of ventricular fibrillation and improved cardiodynamics and myocardial metabolism. BK perfusion induced comparable cardioprotective effects. In addition, perfusion with ACE inhibitors markedly increased the outflow of BK and related kinins from isolated rat hearts. The antiischemic effect of ACE inhibitors and BK were abolished by the addition of L-NNA (1 x 10(-6) mol/l) or icatibant (1 x 10(-9) mol/l). Similar results were found in dogs and rabbits with myocardial infarction. BK and related kinins also seem to be involved in preconditioning and remodeling. The effect of ACE inhibition in LVH was investigated in rats made hypertensive by aortic banding. ACE inhibition with ramipril, in the antihypertensive dose of 1 mg/kg/day for 6 weeks, prevented the increase in blood pressure and the development of LVH. A lower, nonantihypertensive dose of the ACE inhibitor (10 micrograms/kg/day for 6 weeks) had no effect on the increase in blood pressure or on plasma ACE activity, but also prevented LVH after aortic banding.4+ off
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PMID:Contribution of kinins to the cardiovascular actions of angiotensin-converting enzyme inhibitors. 778 79

The effect of chronic angiotensin converting enzyme (ACE) inhibition on the incidence of fatal ventricular fibrillation during regional myocardial ischaemia and reperfusion is not known. A reduction in cardiac angiotensin II and/or a vagomimetic response may result in antiarrhythmic activity. Pigs pre-treated with the ACE inhibitor trandolapril 0.3 mg.kg-1 or placebo orally for 10 days were subjected to thoracotomy. The left anterior descending coronary artery was ligated (CAL) for 20 min and reperfused for 45 min. Trandolapril decreased cardiac ACE activity and prevented the fall in the ventricular fibrillation threshold (VFT) during ischaemia: after 5 min of ischaemia the VFT in the trandolapril group was 25.5 +/- 4.6 mA (mean +/- SEM) vs 13.1 +/- 2.2 mA in the placebo group (P < 0.05). Trandolapril also decreased the incidence of spontaneous ventricular fibrillation during reperfusion to 1/6 vs 6/7 in the placebo group (P < 0.05). Heart rate in the trandolapril group fell. During ischaemia, trandolapril increased blood flow in the non-ischaemic zone, but decreased blood flow in the central ischaemic zone of the left ventricle. Similarly it decreased tissue levels of phosphocreatine in this zone. During reperfusion trandolapril increased blood flow both in non-ischaemic and central ischaemic zones. Chronic oral pre-treatment with trandolapril resulted in marked antifibrillatory effects which were associated with inhibition of cardiac ACE activity and a decreased heart rate.
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PMID:Chronic oral pretreatment with the angiotensin converting enzyme inhibitor, trandolapril decreases ventricular fibrillation in acute ischaemia and reperfusion. 792 22

The analysis of the outcome of patients after myocardial infarction in general, as well as of studies to predict the outcome of asymptomatic post-myocardial infarction patients by non-invasive methods, leads to the following conclusions: 1) The incidence of ventricular fibrillation and mortality after acute myocardial infarction has been declining since the 1970s (2); the causes for this reduction are presumably multifactorial (thrombolysis of acute infarction, administration of ACE-inhibitors and increasing prescription of beta-blockers, improvement of intensive care medicine, rigorous correction of risk factors). 2) Development of ventricular tachycardia, electrocardiographically documented ventricular fibrillation or successful reanimation due to sudden circulatory arrest in clinical studies of post-myocardial infarction patients are endpoints which in future studies must be differentiated from each other. 3) In contrast to previous assumptions, the outcome of patients with primary ventricular fibrillation after acute myocardial infarction, that is, without preceding symptoms is guarded, so that such an event should prompt invasive diagnostic evaluation (coronary arteriography, programmed stimulation (?)). 4) Newer methods for risk stratification after myocardial infarction during the chronic phase, such as programmed stimulation, late potential analysis from the body surface as well as programmed ventricular stimulation appear to be superior to more conventional methods such as long-term ECG monitoring as well as exercise testing. It is recommended that all methods which determine the arrhythmogenic substrate are combined with a parameter of left ventricular ejection fraction because of the paramount importance of left ventricular pump function.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Ventricular tachyarrhythmia in acute and chronic myocardial ischemia: value of diagnostic procedures]. 815 56

The susceptibility to ventricular arrhythmias under the conditions of cardiac ischemia and reperfusion was investigated in the Langendorff heart preparation of rats fed for eight weeks a standard chow enriched with 2% of pulverized wild garlic leaves. The isolated hearts were perfused with a modified Krebs-Henseleit solution. The incidence of ventricular fibrillation (VF) during 20 min occlusion of the descending branch of the left coronary artery (LAD) was significantly reduced in the wild garlic group as compared to untreated controls (20% vs 88%). The same holds for the size of the ischemic zone (33.6% vs 40.9% of heart weight). In the reperfusion experiments (5 min after 10 min ischemia), ventricular tachycardia (VT) occurred in 70% of the wild garlic group vs 100% in untreated controls and VF in 50% vs 90%. The time until occurrence of extrasystoles, VT or VR was prolonged. No significant alterations in cardiac fatty acid composition could be observed. Although the prostacyclin production was slightly increased in hearts of the wild garlic group, inhibition of cyclooxygenase by acetylsalicylic acid (ASA; aspirin) could not completely prevent the cardioprotective effects suggesting that the prostaglandin system does not play a decisive role in the cardioprotective action of wild garlic. Furthermore, a moderate angiotensin converting enzyme (ACE) inhibiting action of wild garlic was found in vitro as well as in vivo that could contribute to the cardioprotective and blood pressure lowering action of wild garlic. Whether a free radical scavenging activity of wild garlic is involved in its cardioprotective effects remains to be established.
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PMID:Cardioprotective actions of wild garlic (allium ursinum) in ischemia and reperfusion. 845 76

In ischemia, the heart generates and releases kinins as mediators that seem to have cardioprotective actions. Kinin-generating pathways are present in the heart. Kininogen, kininogenases, kinins, and B2 kinin receptors can be measured in cardiac tissue. Kinins are released under conditions of ischemia. In anesthetized rats and dogs with coronary artery ligation and in human patients with myocardial infarction, kinin plasma levels are increased. In isolated rat hearts, the outflow of kinins is enhanced during ischemia but markedly attenuated after deendothelialization, pointing to the coronary vascular endothelium as the main possible source. Kinins administered locally exert beneficial cardiac effects. In isolated rat hearts with ischemia-reperfusion injuries, perfusion with bradykinin (BK) reduces the duration and incidence of ventricular fibrillation, improves cardiodynamics, reduces release of cytosolic enzymes, and preserves energy-rich phosphates and glycogen stores. In anesthetized animals, intracoronary BK is followed by comparable beneficial changes and limits infarct size. Inhibition of breakdown of BK and related peptides induces beneficial cardiac effects. Treatment with ACE inhibitors such as ramipril increases cardiac kinin levels and reduces post-ischemic reperfusion injuries in isolated rat hearts and infarct size in anesthetized animals. The importance of an intact endothelium that continuously generates kinins is supported by observations that basal and ramipril-induced release of kinins and PGI2 is markedly reduced after deendothelialization of isolated hearts. Blockade of B2 kinin receptors increases ischemia-induced effects. Endothelial formation of NO and PGI2 by ACE inhibition is prevented by the specific B2 kinin receptor antagonist icatibant. In isolated hearts, ischemia-reperfusion injuries deteriorate with icatibant, which also abolishes the cardioprotective effects of ACE inhibitors and of exogenous BK. Infarct size reduction by ACE inhibitors and by BK in anesthetized animals is reversed by icatibant. Kinins contribute to the cardioprotective effects associated with ischemic preconditioning because preconditioning or BK-induced antiarrhythmic and infarct size-limiting effects are attenuated by icatibant. In conclusion, kinins may act as mediators of endogenous cardioprotective mechanisms. Kinins are generated and released during ischemia, with subsequent formation of PGI2 and NO probably derived mainly from the coronary vascular endothelium. Their cardioprotective profile resembles that of ACE inhibitors.
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PMID:Role of kinins in the pathophysiology of myocardial ischemia. In vitro and in vivo studies. 852 1


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