Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.15.1 (ACE)
 18,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A decrease in cardiac output in patients with congestive heart failure due to dilated cardiomyopathy is compensated by stimulation of the sympathetic nervous system and the renin-angiotensin-aldosterone system. The increase in plasma norepinephrine and depletion of norepinephrine in the myocardium as well as the disturbance of beta-adrenal and baroreceptor function reflect the limits of the sympathetic nervous stimulation. Together with augmented levels of angiotensin II and vasopressin, this stimulation leads to a significant increase in systemic vascular resistance. Sustained stimulation of at least one of these mechanisms can cause further impairment of the left ventricular function. The severity and prognosis of congestive heart failure due to dilated cardiomyopathy is expressed by the plasma norepinephrine concentration and by its myocardial depletion. Ultimately, activation of the compensatory mechanisms provides the basis for therapeutic approaches: 1. reduction of afterload and systemic vascular resistance and/or 2. diminution of the sympathetic nervous activity. For about the last ten years, ACE inhibitors have been used as pharmacological treatment in addition to positive inotropic and vasodilating substances. Captopril, one of the first orally applicable drugs, reduces left ventricular filling pressure, pulmonary capillary pressure, systemic vascular resistance and increases the cardiac output. Beside the hemodynamic improvement, a decrease in plasma norepinephrine and aldosterone can be observed. Vasodilators and alpha-blocking agents can also reduce afterload and systemic vascular resistance in patients with congestive heart failure due to dilated cardiomyopathy, and may lead to hemodynamic improvement. The main limitations of their long-term application are relatively short duration of action, reflex activation of the renin-angiotensin system due to vasodilation and induction of tolerance.
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PMID:[Sympathetic activity in patients with heart failure due to idiopathic dilated cardiomyopathy: effect of ACE inhibitors and other vasodilators]. 219 17

The effect of the angiotensin converting enzyme inhibitor Captopril on the severity of radiation-induced epilation and moist desquamation and the incidence of skin tumours was determined for up to 52 weeks in male rats. The irradiation consisted of a range of single doses (0, 10, 20, 30 Gy) of 60Co gamma rays to a 3.5 cm2 right hemithorax port. Half of each radiation dose group consumed control powdered chow, and half consumed chow containing Captopril (50 mg/kg/day) continuously after irradiation. There were time- and radiation-dose-dependent increases in all three skin reactions. Rats exposed to 10 Gy exhibited a mild and transient epilation, but no moist desquamation or neoplasia in the radiation port. In animals exposed to 30 Gy, however, epilation began at 2 weeks after irradiation, reached a peak at approximately 7 weeks, then persisted essentially unchanged through 52 weeks. Captopril had no significant effect on the epilation reaction. Two waves of moist desquamation were observed after 30 Gy. The first appeared at 3 weeks after irradiation, reached a peak from 6-10 weeks, then subsided partially but significantly from 12-26 weeks. The second wave of moist desquamation began at 26-28 weeks, often was ulcerative, and occasionally was accompanied by the appearance of tumours in the irradiated volume. Captopril significantly (p less than 0.05) reduced the severity of both phases of the moist desquamation reaction after 30 Gy, and reduced the percentage of animals exhibiting the most severe desquamation score (involving 50% of the radiation port). Of particular interest was the observation that Captopril also reduced the incidence of tumours. Of the 14 tumours detected, all were malignant (fibrosarcomas, squamous cell carcinomas), and only three (p less than 0.05) occurred in rats receiving Captopril. Multiple tumours (three cases), tumours induced by 20 Gy (three cases), and tumours appearing before 6 months (one case) were observed only in rats consuming control diet, never in Captopril-treated animals. Animals which developed tumours in the second 6 months post-irradiation exhibited significantly more severe moist desquamation during the first 6 months than did the tumour-free members of their treatment group. Thus Captopril, known to ameliorate acute lung damage in irradiated rats, also reduces chronic benign and malignant skin reactions in the radiation treatment field.
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PMID:The effect of Captopril on benign and malignant reactions in irradiated rat skin. 219 82

The pathogenesis of heart failure is not yet fully understood. In animal models there is some evidence to suggest a role for free radicals (FRs). We have investigated malondialdehyde - LM in plasma of patients with heart failure and found it to be raised when compared to controls. We present data to show that Captopril, a drug with an ACE inhibitory effect is a FR scavenger both in vitro and ex-vivo in patients with heart failure.
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PMID:Oxidative damage in chronic heart failure: protection by captopril through free radical scavenging? 224 3

The angiotensin converting enzyme inhibitor captopril ameliorates radiation-induced pulmonary endothelial dysfunction in rats. The present study determined whether captopril also reduces collagen (hydroxyproline) accumulation in the lungs of rats sacrificed 2 months after a range of single doses (0-30 Gy) of 60Co gamma rays to the right hemithorax. Captopril was administered in the feed at a regimen of 0, 25, or 50 mg/kg/day continuously after irradiation. Mast cell counts also were obtained from lungs of all animals exposed to 30 Gy. In rats receiving no captopril, there was a radiation dose-dependent increase in right lung hydroxyproline (HP) content and in HP concentration per g wet weight. Captopril produced a drug dose-dependent suppression in this radiation-induced HP accumulation. At a dose of 50 mg/kg/d, captopril reduced the slope of the radiation dose response curve for lung HP content by a factor of 1.7, and completely prevented the increase in HP concentration. At an isoeffect level of 550 micrograms HP per right superior lobe, this dose of captopril exhibited a DRF of 1.7 +/- 0.2. In rats exposed to 30 Gy, moreover, the number of mast cells per mm2 of alveolar cross-sectional surface area decreased from 105 +/- 8 to 100 +/- 7 and 59 +/- 5 in the groups given 0, 25 or 50 mg/kg/d of captopril, respectively, (vs none in sham-irradiated rats). These data are the first to demonstrate that the ACE inhibitor captopril might provide a novel intervention in the pathogenesis of radiation fibrosis.
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PMID:Captopril reduces collagen and mast cell accumulation in irradiated rat lung. 226 65

1. Effects of inhibition of angiotensin converting enzyme (ACE, EC 3.4.15.1) in brain on psychomotor, exploratory, stereotyped and cognitive behaviour in rats were investigated. To inhibit brain ACE captopril (D-3-mercaptopropanoyl-L-proline) was given orally (p.o., 50 mg/kg) or intracerebroventricularly (i.c.v., 5 micrograms/rat). 3. Captopril given p.o. but not i.c.v. significantly enhanced stereotypy, overall number of conditioned avoidance responses, and decreased blood pressure. 4. No statistically significant influence of captopril given by either route on the number of crossings, rearings and bar approaches in the open field, performance of passive avoidance and number of correct choices as well as the speed of running for food in the T-maze was observed. 5. In conclusion, a small decrease of the activity of nigrostriatal dopaminergic system caused by the decrease of AII and/or increase of bradykinin, substance P, enkephalins and neurotensin in brain resulting from ACE inhibition is postulated.
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PMID:Some behavioural effects of captopril in rats. 227 85

We have previously demonstrated that Captopril, an inhibitor of angiotensin converting enzyme (ACE), ameliorates experimental systemic lupus erythematosus in inbred MRL lpr/lpr (MRL/l) mice. In contrast, Enalapril, another ACE inhibitor with antihypertensive properties but lacking a thiol group, did not show similar beneficial effects. To better understand the mode of action of captopril in the autoimmune disease we have evaluated its immunomodulatory properties with special emphasis on antigen-specific and polyclonal B- and T-cell activation. The results obtained strongly suggest that Captopril exerts its immunomodulatory effects through stimulation of T-lymphocytes.
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PMID:Differential effects of captopril and enalapril, two angiotensin converting enzyme inhibitors, on immune reactivity in experimental lupus disease. 228 27

Captopril, which is a thiol containing angiotensin converting enzyme (ACE) inhibitor that has a close structural similarity to D-penicillamine, behaves as a disease modifying antirheumatic drug (DMARD) in rheumatoid arthritis (RA). In order to ascertain whether the DMARD-like properties of captopril reside in its ability to inhibit ACE or in the thiol group, we evaluated pentopril (CGS-13945) in patients with active RA. This recently synthesized drug is a nonthiol containing ACE inhibitor. Pentopril produced little clinical improvement and no biochemical improvement in a group of 15 patients with RA, many of whom were unable to tolerate it because of in-effect or side effects. A reduction in serum ACE activity and a modest fall in blood pressure suggested that the drug was exerting its pharmacological effect. Our study strengthens the argument that the therapeutic benefit of captopril in RA probably lies in its thiol group rather than in its enzyme inhibition properties, and that the thiol group may be the effective moiety in some other DMARD.
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PMID:A clinical and biochemical assessment of a nonthiol ACE inhibitor (pentopril; CGS-13945) in active rheumatoid arthritis. 235 68

The main effect of the ACE-inhibitors is a reduction of the peripheral resistance and according to that an increase of blood-flow to the organs. Direct effects on the heart are of minor importance. The exact mechanism of action is not fully understood; the main role plays obviously the inhibition of the angiotensin converting enzyme itself; in addition may be effects on the kallikrein-bradykinin-prostaglandin-system are of importance. The pharmacodynamical effects depend on the plasma-concentration and therefore on the pharmacokinetics. These are different with Captopril and Enalapril: Captopril acts directly whereas Enalapril is a "prodrug". With the nowadays used doses Captopril and Enalapril are widely free of side-effects. With the exception of patients with negative sodium-balance (salt-poor diet and/or treatment with diuretics) or patients with renal insufficiency (sometimes increase of creatinine and potassium). In the first group of patients the first dose of ACE-inhibitors should be administered in the evening before going to bed, in the second group creatinine and potassium must be checked 5 to 7 days after an initiation of treatment.
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PMID:[Clinical pharmacology of ACE inhibitors]. 240 45

Before efficacy of therapy has been proven in large populations years or decades may pass. Meanwhile the medical profession has to rely on probabilities. This holds true regarding improvement of prognosis of CHF by ACE inhibition. While symptomatic improvement of CHF by addition of ACE-inhibition. While symptomatic improvement of CHF by addition of ACE-inhibitors has been demonstrated in numerous studies, improvement of prognosis has not yet been demonstrated entirely sufficiently. Only one trial has been published so far in a severely ill but not very exactly defined population (66). Animal studies and several small or interim published trials, however, show that the positive influence of ACE-inhibitors on CHF pathophysiology and symptomatology might favourable affect the prognosis as well. The SAVE trial and the SOLVD trial - both have randomized several thousand patients - will give answers concerning the influence of Captopril and Enalapril on prognosis of symptomatic as well as asymptomatic left ventricular dysfunction and on progression of left ventricular dilatation. The VHEFT II trial will compare the effect of ACE-inhibitors with the combination of ISDN and Hydralazine. Results will be available within the first few years of this decade.
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PMID:[Heart insufficiency and life expectancy--the role of ACE inhibitors]. 240 50

The mechanisms underlying potentiation by captopril of the depressor responses to arachidonic acid were studied in chloralose-anaesthetized rats. Captopril, in a dose (0.5 mg/kg, i.v.) which inhibited the pressor responses to angiotensin I (0.03-1 microgram/kg, i.v.), enhanced the depressor responses to bradykinin (3-300 micrograms/kg, i.v.) and potentiated the hypotensive action of arachidonic acid (3 mg/kg, intravenously). This phenomenon was observed not only when captopril and arachidonic acid were administered intravenously, but also when these compounds were injected directly into the aortic arch. The enhancement of arachidonic acid-induced hypotension by captopril was not significantly affected by pretreatment with a low dose of aprotinin (3 mg/kg, i.v.), but was abolished by bilateral nephrectomy or by pretreatment with a higher dose of aprotinin (6 mg/kg, i.v.). It is suggested that captopril augments the depressor responses to arachidonic acid by inhibiting angiotensin converting enzyme. This results in accumulation of bradykinin which in turn increases release of vasodilator prostaglandins, originating most probably, from the kidneys. The possibility that blockade of angiotensin II formation by captopril may leave the vasodilator action of prostaglandin unopposed cannot be excluded.
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PMID:Mechanisms of captopril-induced potentiation of the depressor responses to arachidonic acid in rats. 242 82


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