Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endothelial dysfunction is recognized as an early event in the pathogenesis of atherosclerosis. Many risk factors cause endothelial dysfunction, such as hypercholesterolemia, hypertension, cigarette smoking, and diabetes mellitus. The precise steps leading to endothelial dysfunction are still being elucidated. Increasing evidence indicates that oxidized low-density lipoprotein (LDL) cholesterol (ox-LDL) plays an important role in endothelial dysfunction. Ox-LDL induces endothelial injury; inhibits apoptosis, monocyte adhesion, and platelet aggregation; and inhibits endothelial nitric oxide synthase (eNOS) expression/activity, all of which contribute to atherosclerotic process. Several pharmacologic agents, such as 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins), have been shown to provide endothelial stabilization through mechanisms that go beyond their primary therapeutic effect. Alteration in the endothelial function might result from increase in eNOS activity, reduction in the production of free radicals, inhibition of ox-LDL action, or other undefined mechanisms. This review will focus on the protective role and some of the mechanisms of statins in ox-LDL-induced endothelial dysfunction.
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PMID:3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors protect against oxidized low-density lipoprotein-induced endothelial dysfunction. 1269 73

Progesterone (P) is a potent antagonist of the human mineralocorticoid receptor (MR) in vitro. We have previously demonstrated effective downstream metabolism of P in the kidney. This mechanism potentially protects the MR from P action. Here, we have investigated the expression and functional activity of steroidogenic enzymes in human kidney. RT-PCR analysis demonstrated the expression of 5 alpha-reductase type 1, 5 beta-reductase, aldo-keto-reductase (AKR) 1C1, AKR1C2, AKR1C3, 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) type 2, and 17 alpha-hydroxylase/17,20-lyase (P450c17). The presence of 3 beta-HSD type 2 and P450c17 indicated that conversion of pregnenolone to dehydroepiandrosterone (DHEA) and to androstenedione may take place effectively in kidney. To investigate this further, we incubated kidney subcellular fractions with radiolabeled pregnenolone. This resulted in efficient formation of DHEA from pregnenolone, indicating both 17 alpha-hydroxylase and 17,20-lyase activities exerted by P450c17. Radiolabeled DHEA was converted via androstenedione, androstenediol, and testosterone, indicating both 3 beta-HSD type 2 activity and 17 beta-HSD activity. In addition, the conversion of testosterone to 5 alpha-dihydrotestosterone was detectable, indicating 5 alpha-reductase activity. In conclusion, we verified the expression and functional activity of several enzymes involved in downstream metabolism of P and androgen synthesis in human kidney. These findings may be critical to the understanding of water balance during the menstrual cycle and pregnancy and of sex differences in hypertension.
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PMID:The human kidney is a progesterone-metabolizing and androgen-producing organ. 1278 91

Current strategies for both the primary and secondary prevention of coronary heart disease (CHD) focus on the traditional risk factors, such as hypertension, smoking cessation, and cholesterol, as the primary determinants of the cardiac risk profile, with particular emphasis on the reduction of low-density lipoprotein cholesterol (LDL-C) to targeted goal levels as endorsed by the National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATPIII). Large primary and secondary prevention trials with the hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) have demonstrated varying reductions in cardiovascular events associated with similar changes in LDL-C levels, suggesting statins may possess additional beneficial effects on other risk factors. Retrospective analyses of many statin trials have evaluated the association between several polymorphic candidate genes (apolipoprotein E, stromelysin-1, beta-fibrinogen, cholesteryl ester transfer protein, lipoprotein lipase, hepatic lipase, and platelet glycoprotein III) which have been identified as predictors of disease severity and both metabolic and clinical response to statin therapy. These results suggest that statin therapy improves plasma lipid profiles in all patients, but preferentially benefits individuals who carry a high risk, variant genotype for these risk factors as compared to individuals with the wild-type genotype. These observations suggest that determining individual patient genotype may be useful in optimizing the benefits of statin therapy. These hypothesis-generating data need to be prospectively evaluated in genotyped patients.
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PMID:Genetic polymorphisms in emerging cardiovascular risk factors and response to statin therapy. 1284 89

The increasing prevalence of type 2 diabetes is a major problem for healthcare providers globally, since it is associated with serious microvascular and macrovascular complications. Although microvascular complications can be largely reduced with strict glycemic control, prevention of macrovascular disease involves a multifaceted approach that addresses all major risk factors, including dyslipidemia, hypertension, and insulin insensitivity. In particular, the treatment of diabetic dyslipidemia is a major challenge for diabetologists and cardiologists, as it is characterized by an array of lipid abnormalities. The management of diabetic dyslipidemia should initially include lifestyle approaches such as improved nutrition and weight reduction; however, the majority of patients require the addition of pharmacotherapy. Whilst insulin and/or oral hypoglycemic drugs are generally prescribed for the treatment of hyperglycemia, the addition of lipid-lowering drugs may be necessary for the control of diabetic dyslipidemia. The American Diabetes Association guidelines recommend lowering of low-density lipoprotein cholesterol (LDL-C) as a first priority. Hydroxy-methylglutaryl coenzyme A reductase inhibitors (statins) are recommended for first-line therapy in diabetic patients, since these agents are effective at reducing LDL-C levels. Whilst statins provide effective control of dyslipidemia in the majority of patients, more efficacious treatment regimens would provide greater benefit to more patients. Combination therapies may provide one solution to obtaining maximal lipid profile modifications, although the introduction of new, more efficacious agents for use as monotherapy may provide a more acceptable option, as drug combinations are often associated with poor tolerability and patient compliance.
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PMID:Statin therapy for the treatment of diabetic dyslipidemia. 1287 5

Two isoforms of 11beta-hydroxysteroid dehydrogenase (11beta-HSD) interconvert the active glucocorticoid, cortisol, and inactive cortisone. 11beta-HSD1 acts predominantly as an oxo-reductase in vivo using NADP(H) as a cofactor to generate cortisol. In contrast, 11beta-HSD2 is a NAD-dependent dehydrogenase inactivating cortisol to cortisone, thereby protecting the mineralocorticoid receptor from occupation by cortisol. In peripheral tIssues, both enzymes serve to control the availability of cortisol to bind to corticosteroid receptors. 11beta-HSD2 protects the mineralocorticoid receptor from cortisol excess; mutations in the HSD11B2 gene explain an inherited form of hypertension, the syndrome of 'apparent mineralocorticoid excess', in which 'Cushing's disease of the kidney' results in cortisol-mediated mineralocorticoid excess. Inhibition of 11beta-HSD2 explains the mineralocorticoid excess state seen following liquorice ingestion and more subtle defects in enzyme expression might be involved in the pathogenesis of 'essential' hypertension. 11beta-HSD1 by generating cortisol in an autocrine fashion facilitates glucocorticoid receptor-mediated action in key peripheral tIssues including liver, adipose tissue, bone and the eye. 'Cushing's disease of the omentum' has been proposed as an underlying mechanism in the pathogenesis of central obesity and raises the exciting possibility of selective 11beta-HSD1 inhibition as a novel therapy for patients with the metabolic syndrome. 'Pre-receptor' metabolism of cortisol via 11beta-HSD isozymes is an important facet of corticosteroid hormone action. Aberrant expression of these isozymes is involved in the pathogenesis of diverse human diseases including hypertension, insulin resistance and obesity. Modulation of enzyme activity may offer a future therapeutic approach to treating these diseases whilst circumventing the endocrine consequences of glucocorticoid excess or deficiency.
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PMID:Tissue-specific Cushing's syndrome, 11beta-hydroxysteroid dehydrogenases and the redefinition of corticosteroid hormone action. 1294 16

The development of statins improved the therapy of hypercholesterolemia and atherosclerotic disease tremendously. The beneficial effects of statins were clearly demonstrated in large scale primary and secondary prevention studies. In addition to the reduction of plasma cholesterol, inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase also results in the depletion of intermediates of cholesterol biosynthesis that are important for cellular integrity. The so called pleiotrophic effects of statins and probably also their adverse events can be attributed to the inhibition of synthesis of these intermediates. The review article describes the pathogenesis of atherosclerosis, the pharmacokinetic and pharmacodynamik of statins, and their pleiotrophic effects concerning endothelial function, LDL (low density lipoprotein) oxidation, macrophages, smooth muscle cell proliferation, atherosclerotic plaque, platelets, thrombosis, proinflammatory factors, haemorheology, hypertension, venous thrombosis, bone metabolism, stroke, and the possible influence on the prevention of Alzheimer's disease.
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PMID:[Pleiotrophic effect of statins (3-hydroxy-3-methylglutaryl-coenzyme a reductase inhibitors)]. 1367 44

A rapid screening assay for chemicals inhibiting 11beta-hydroxysteroid dehydrogenase (11beta-HSD) type 1 or type 2 using lysates from stably transfected cells was developed. Here, we tested a series of environmental chemicals for anti-11beta-HSD activities. Inhibition of 11beta-HSD2, which may cause cortisol-dependent activation of the mineralocorticoid receptor with sodium retention and hypertension, was observed for several compounds, with diethylcarbamate being the most potent inhibitor (IC50 6.3 microM). Abietic acid inhibited both 11beta-HSD1 (IC50 27 microM for reduction and 2.8 microM for oxidation) and 11beta-HSD2 (IC50 12 microM). Our results demonstrate for the first time that flavanone selectively inhibits 11beta-HSD1 reductase activity: this enzyme being considered as essential for the local activation of glucocorticoids and representing a potential target for the therapeutic treatment of diabetes type 2. Flavanone and 2'-hydroxyflavanone efficiently inhibited reductive (IC50 18 and 10 microM) but not oxidative activity. We observed a reduced inhibitory effect of hydroxylated flavanone derivatives and of flavones containing a double-bond between atom C2 and C3. Flavanone was specific for 11beta-HSD1 and did not inhibit 11beta-HSD2. Our results reveal that a variety of environmental compounds exert distinct inhibitory effects on 11beta-HSD1 and 11beta-HSD2, opening the possibility for selectively modulating local cortisone/cortisol availability in vivo.
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PMID:A rapid screening assay for inhibitors of 11beta-hydroxysteroid dehydrogenases (11beta-HSD): flavanone selectively inhibits 11beta-HSD1 reductase activity. 1465 49

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors have been shown to prevent or reverse hypertrophy of the LV in several models of left ventricular hypertrophy. The aim of the present study was to determine whether treatment with simvastatin can prevent hypertension, reduction of tissue nitric oxide synthase activity and left ventricular (LV) remodeling in NG-nitro-L-arginine methyl ester(L-NAME)-induced hypertension. Four groups of rats were investigated: control, simvastatin (10 mg/kg), L-NAME (40 mg/kg) and L-NAME + simvastatin (in corresponding doses). Animals were sacrificed and studied after 6 weeks of treatment. The decrease of NO-synthase activity in the LV, kidney and brain was associated with hypertension, LV hypertrophy and fibrosis development and remodeling of the aorta in the L-NAME group. Simvastatin attenuated the inhibition of NO-synthase activity in kidney and brain, partly prevented hypertension development and reduced the concentration of coenzyme Q in the LV. Nevertheless, myocardial hypertrophy, fibrosis and enhancement of DNA concentration in the LV, and remodeling of the aorta were not prevented by simultaneous simvastatin treatment in the L-NAME treated animals. We conclude that the HMG-CoA reductase inhibitor simvastatin improved nitric oxide production and partially prevented hypertension development, without preventing remodeling of the left ventricle and aorta in NO-deficient hypertension.
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PMID:Effect of simvastatin on remodeling of the left ventricle and aorta in L-NAME-induced hypertension. 1469 5

Dyslipidemia, characterized by elevated serum levels of triglycerides and reduced levels of total cholesterol, low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol, has been recognized in patients with human immunodeficiency virus (HIV) infection. It is thought that elevated levels of circulating cytokines, such as tumor necrosis factor-alpha and interferon-alpha, may alter lipid metabolism in patients with HIV infection. Protease inhibitors, such as saquinavir, indinavir and ritonavir, have been found to decrease mortality and improve quality of life in patients with HIV infection. However, these drugs have been associated with a syndrome of fat redistribution, insulin resistance, and hyperlipidemia. Elevations in serum total cholesterol and triglyceride levels, along with dyslipidemia that typically occurs in patients with HIV infection, may predispose patients to complications such as premature atherosclerosis and pancreatitis. It has been estimated that hypercholesterolemia and hypertriglyceridemia occur in greater than 50% of protease inhibitor recipients after 2 years of therapy, and that the risk of developing hyperlipidemia increases with the duration of treatment with protease inhibitors. In general, treatment of hyperlipidemia should follow National Cholesterol Education Program guidelines; efforts should be made to modify/control coronary heart disease risk factors (i.e. smoking; hypertension; diabetes mellitus) and maximize lifestyle modifications, primarily dietary intervention and exercise, in these patients. Where indicated, treatment usually consists of either pravastatin or atorvastatin for patients with elevated serum levels of LDL-C and/or total cholesterol. Atorvastatin is more potent in lowering serum total cholesterol and triglycerides compared with other hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, but it is also associated with more drug interactions compared with pravastatin. Simvastatin and lovastatin are significantly metabolized by cytochrome P450 enzymes (CYP3A4) and are therefore not recommended for coadministration with protease inhibitors. A fibric acid derivative (gemfibrozil or fenofibrate) should be used in patients with primary hypertriglyceridemia. However, it must be kept in mind that protease inhibitors, such as nelfinavir and ritonavir, induce enzymes involved in the metabolism of the fibric acid derivatives and may, therefore, reduce the lipid-lowering activity of coadministered gemfibrozil or fenofibrate. In certain patients HMG-CoA reductase inhibitors may be used in combination with fibric acid derivatives but patients should be carefully monitored for liver and skeletal muscle toxicity. Select patients may experience improvements in serum lipid levels when their offending protease inhibitor(s) is/are exchanged for efavirenz, nevirapine, or abacavir; however each patient's virologic and immunologic status must be taken closely into consideration.
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PMID:Management of protease inhibitor-associated hyperlipidemia. 1472 85

Combined hyperlipidemia is increasing in frequency and is the most common lipid disorder associated with obesity, insulin resistance and diabetes mellitus. It is associated with other features of the metabolic syndrome including hypertension, hyperuricemia, hyperinsulinemia and highly atherogenic subfractions of lipoprotein remnant particles including small dense low density lipoprotein-cholesterol. This review examines the mechanisms by which combined hyperlipidemia arises and the various drugs including fibric acid derivatives, hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, and nicotinic acid which can be used either as monotherapy or in combination to manage it and to improve prognosis from atherosclerotic disease in diabetes mellitus, insulin resistant states and primary combined hyperlipidemia. The therapeutic approach to combined hyperlipidemia involves determination of whether the cause is hepatocyte damage or metabolic derangements. Combined hyperlipidemia due to hepatocyte damage should be treated by attention to the primary cause. In the case of metabolic dysfunction because of imbalance in glucose and fat metabolism, therapy of diabetes mellitus and obesity should be optimised prior to commencement of lipid lowering drugs. Both fibric acid derivatives and HMG-CoA reductase inhibitors can be used in the treatment of combined hyperlipidemia with fibric acid derivatives having greater effects on triglycerides and HMG-CoA reductase inhibitors on LDL-C though both have effects on the other cardiovascular risk factors. There is some evidence of benefit with both interventions in mild combined hyperlipidemias and large scale trials are underway. Fibric acid derivatives and HMG-CoA reductase inhibitor therapy can be combined with care, provided that gemfibrozil is avoided, fibric acid derivatives are given in the mornings and shorter half -life HMG-CoA reductase inhibitors are used at night. Combined hyperlipidemia emergencies occur with predominant hypertriglyceridemia in pregnancy or as a cause of pancreatitis. Therapy in the former should aim to reduce chylomicron production by a low fat diet and intervention to suppress VLDL-C secretion using omega-3 fatty acids. In the latter case, fluid therapy alone and medium chain plasma triglyceride infusions usually reduce levels satisfactorily though apheresis may be required. Blood glucose levels also need aggressive management in these conditions. Combined hyperlipidemia is likely to become an increasing problem with the increase in the prevalence of obesity and diabetes mellitus and needs aggressive management to reduce cardiovascular risk.
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PMID:Drug treatment of combined hyperlipidemia. 1472 15


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