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 aim of the investigation was to assess and compare the effects of a calcium channel antagonist, (i.e. amlodipine) and an ACE-inhibitor (i.e. lisinopril) in reducing chronic left ventricular hypertrophy in 15-week old spontaneously hypertensive rats (SHR). Changes in cardiac hypertrophy were assessed after 8 weeks by measuring the fractional rates of protein synthesis using a 'flooding dose' of [3H]-phenylalanine for 10 min. Blood pressure was monitored throughout the treatment period in both SHR and Wistar-Kyoto control rats (WKY). The results showed a decrease in blood pressure by amlodipine after 1 week of treatment which was further reduced at 4 to 8 weeks. Lisinopril caused immediate and sustained reductions in blood pressure (190 mmHg to 130 mmHg, P < 0.001). After 8 weeks of treatment in SHR rats, amlodipine had no significant effect on left ventricular weight (P > 0.05), whereas lisinopril caused a marked reduction. The protein content and RNA were also not changed by amlodipine. In contrast, lisinopril significantly lowered the tissue protein, RNA and DNA content (P < 0.001). The changes in the left ventricles of lisinopril-treated SHR rats were accompanied by an increase in the fractional synthesis rate of left ventricular myofibrillar proteins (+12 per cent, P < 0.025). The synthesis rate per unit RNA was also increased in right ventricular tissue of lisinopril-treated SHR rats. However, amlodipine had no effect on the fractional synthesis rates of any of the left-ventricular fractions of SHR rats (P > 0.05). The cellular efficiency in the right ventricle was also increased in amlodipine-treated SHR rats, indicating a moderate effect on protein metabolism. In conclusion, amlodipine had minimal effects in the reduction of established left ventricular hypertrophy (LVH), despite reducing the blood pressure, whereas lisinopril caused regression of LVH. These events were associated with small changes in protein synthesis rates, with the contractile protein showing an increase.
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PMID:Protein synthesis in the hypertrophied heart of spontaneously hypertensive rats and a comparison of the effects of an ACE-inhibitor and a calcium channel antagonist. 753 13

As a consequence of persistently raised blood pressure, left ventricular hypertrophy (LVH) develops as a compensatory mechanism for wall stress induced by the increase in afterload. Recent advances in the fields of molecular biology and genetics are now clarifying the mechanisms involved in the development of LVH. It has been reported that messenger RNA of oncogenes, such as c-fos and c-myc, increases by stretching; these oncogenes contribute to the progression of LVH, the messenger RNA expression of myosin and contractile protein synthesis in the cardiomyocytes. Vasoactive hormones and vascular contracting factors are also reported to have a progressive effect on LVH. In contrast, some antihypertensive agents have been shown to have pharmacological effects on regression of LVH in animals and man. The mechanisms responsible for LVH progression have been extensively studied. In contrast, the mechanisms of LVH regression have not been defined and require elucidation. This paper outlines the basic recognition of the mechanisms of LVH progression and discusses the varied pharmacological actions of calcium antagonists and angiotensin converting enzyme inhibitors on the regression of LVH in man and rats. Although the role of antihypertensive therapy in regression of LVH remains controversial, the calcium antagonist nicardipine appears to have an important role to play in the treatment of LVH in hypertension and in congestive heart failure.
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PMID:Therapeutic advances in the treatment of left ventricular hypertrophy. 837 Mar 75

1. This study was undertaken to determine whether the AT1 receptor directly contributes to hypertension-induced cardiac hypertrophy and gene expressions. 2. Stroke-prone spontaneously hypertensive rats (SHRSP) were given orally an AT1, receptor antagonist (losartan, 30 mg kg-1 day-1), an angiotensin converting enzyme inhibitor (enalapril 10 mg kg-1 day-1), a dihydropyridine calcium channel antagonist (amlodipine, 5 mg kg-1 day-1), or vehicle (control), for 8 weeks (from 16 to 24 weeks of age). The effects of each drug were compared on ventricular weight and mRNA levels for myocardial phenotype- and fibrosis-related genes. 3. Left ventricular hypertrophy of SHRSP was accompanied by the increase in mRNA levels for two foetal phenotypes of contractile proteins (skeletal alpha-actin and beta-myosin heavy chain (beta-MHC)), atrial natriuretic polypeptide (ANP), transforming growth factor-beta-1 (TGF-beta 1) and collagen, and a decrease in mRNA levels for an adult phenotype of contractile protein (alpha-MHC). Thus, the left ventricle of SHRSP was characterized by myocardial transition from an adult to a foetal phenotype and interstitial fibrosis at the molecular level. 4. Although losartan, enalapril and amlodipine lowered blood pressure of SHRSP to a comparable degree throughout the treatment, losartan caused regression of left ventricular hypertrophy of SHRSP to a greater extent than amlodipine (P < 0.01). 5. Losartan significantly decreased mRNA levels for skeletal alpha-actin, ANP, TGF-beta 1 and collagen types I, III and IV and increased alpha-MHC mRNA in the left ventricle of SHRSP. Amlodipine did not alter left ventricular ANP, alpha-MHC and collagen types I and IV mRNA levels of SHRSP. 6. The effects of enalapril on left ventricular hypertrophy and gene expressions of SHRSP were similar to those of losartan, except for the lack of inhibition of collagen type I expression by enalapril. 7. Unlike the hypertrophied left ventricle, there was no significant difference between losartan and amlodipine in the effects on non-hypertrophied right ventricular gene expressions of SHRSP. 8. Our results show that hypertension causes not only left ventricular hypertrophy but also molecular transition of myocardium to a foetal phenotype and interstitial fibrosis-related molecular changes. These hypertension-induced left ventricular molecular changes may be at least in part mediated by the direct action of local angiotensin II via the AT1, receptor.
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PMID:Effects of an AT1 receptor antagonist, an ACE inhibitor and a calcium channel antagonist on cardiac gene expressions in hypertensive rats. 876 77

The diaphragm is the primary muscle of inspiration, and as such uncompromised function is essential to support the ventilatory and gas exchange demands associated with physical activity. The normal healthy diaphragm may fatigue during intense exercise, and diaphragm function is compromised with aging and obesity. However, more insidiously, respiratory diseases such as emphysema mechanically disadvantage the diaphragm, sometimes leading to muscle failure and death. Based on metabolic considerations, recent evidence suggests that specific regions of the diaphragm may be or may become more susceptible to failure than others. This paper reviews the regional differences in mechanical and metabolic activity within the diaphragm and how such heterogeneities might influence diaphragm function in health and disease. Our objective is to address five principal areas: 1) Regional diaphragm structure and mechanics (GAF). 2) Regional differences in blood flow within the diaphragm (WLS). 3) Structural and functional interrelationships within the diaphragm microcirculation (DCP). 4) Nitric oxide and its vasoactive and contractile influences within the diaphragm (MBR). 5) Metabolic and contractile protein plasticity in the diaphragm (SKP). These topics have been incorporated into three discrete sections: Functional Anatomy and Morphology, Physiology, and Plasticity in Health and Disease. Where pertinent, limitations in our understanding of diaphragm function are addressed along with potential avenues for future research.
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PMID:Diaphragm structure and function in health and disease. 921 1

In the following study we examined the combined effect of chronic alcohol administration and anti-hypertensive drug treatment in spontaneously hypertensive rats (SHR). SHR were fed alcohol for six weeks while taking the angiotensin converting enzyme (ACE) inhibitor lisinopril. After six weeks, protein synthesis rates, contractile protein levels and protease activities were examined in control; alcohol; control+lisinopril; alcohol+lisinopril groups. Lisinopril treatment significantly reduced left ventricular mass, protein content and contractile proteins in control rats, but these effects were not as pronounced in alcohol+lisinopril rats. Protein synthesis rates in both mixed and myofibrillar fractions were not significantly different in any of the 4 groups. The enzyme activities of the proteases cathepsin D and dipeptidyl aminopepetidase I increased in control+lisinopril rats, however, this effect was not evident in alcohol+lisinopril rats. Contractile proteins identified by one-dimensional electrophoresis showed that lisinopril treatment reduced all contractile proteins in control rats. However, in alcohol+ lisinopril rats, myosin heavy chain was higher than in control+lisinopril rats. In summary, alcohol ingestion impairs the regression of the hypertrophic myocardium in SHR on ACE-inhibitor treatment, which was reflected by altered protein metabolism. This study suggests that successful anti-hypertensive treatment may not be achieved if alcohol misuse is evident.
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PMID:Poor regression of myocardial hypertrophy following concomitant chronic alcohol ingestion and angiotensin converting enzyme (ACE) inhibition. 1098 38

Changes in tissue protein synthesis in hypertension have usually been measured in vitro in heart from acutely hypertensive rats without consideration of changes in atrial or pulmonary tissue or changes occurring in long-standing hypertension. The objective of the study was to investigate the in vivo changes in cardiopulmonary protein synthesis in three different rat models of chronic hypertension. Hypertension in aortic constriction, the Goldblatt model, and the bromoethylamine model were induced in rats for 30 days. At the end of the experimental period, in vivo rates of protein synthesis were measured with a flooding dose of [3H]phenylalanine (a method which effectively considers precursor pools). Concomitant measurements included quantification of contractile protein and RNA and DNA contents. Indices of protein breakdown were also assessed by selective measurement of protease activities. At the end of 30 days, aortic constriction induced marked increases in protein contents of the left ventricle, septum, left atria, and lungs. Accompanying changes included concomitant increases in RNA and DNA contents. Left ventricular myofibrillary, sarcoplasmic, and stromal protein contents increased in the aortic constriction model. Less marked changes occurred in the Goldblatt model, though the left atria were not significantly affected. In contrast, the bromoethylamine model had no effect on the protein or RNA contents of any region. In all cardiac regions of all three models, fractional rates of protein synthesis were not significantly affected. However, protein synthesis increased in the lungs of both the Goldblatt and bromoethylamine models at 30 days. Protease activities were decreased in the left ventricles of all three models at 30 days, with lysosomal protease activities declining in the aortic constriction model and cytoplasmic protease activities declining in the other two models. The failure of chronic hypertension to increase ventricular synthesis rates may represent inherent limitations in the time frame for measuring protein synthesis in vivo. However, at earlier time points (i.e., 10 days), the aortic constriction model was characterized by marked increases in left ventricular and atrial protein contents, RNA contents, and fractional rates of protein synthesis. This was consistent with the supposition that, in acute phases of hypertrophy, rates of protein synthesis increase, whereas in established hypertrophy, synthesis rates remain unchanged or decrease. The applicability of the aortic constriction model was investigated by examining the effects of the angiotensin converting enzyme inhibitor lisinopril (5 mg/kg/day). After 30 days treatment, lisinopril impeded the increase in left ventricular mixed and myofibrillar proteins. This effect was accompanied by an apparent increase in protein synthesis. In conclusion, although all three chronic models are able to induce hypertension, varying degrees of hypertrophy develop, which are more pronounced in the aortic constriction model. Accompanying changes include hypertrophy in the atria, reduced rates of ventricular proteolytic activity, and altered rates of protein metabolism in the lungs.
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PMID:In vivo protein synthetic rates of atrial, ventricular, and pulmonary tissue proteins in aortic constriction, goldblatt, and bromoethylamine models of hypertension. 1117 Jul 87