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)

In the kidney and colon 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) inactivates cortisol to cortisone, thereby protecting the non-selective mineralocorticoid receptor from cortisol. Deficiency of 11beta-HSD2 results in cortisol-mediated sodium retention and hypertension, suggesting that the physiological regulation of 11beta-HSD2 in mineralocorticoid target tissues may be important in modulating sodium homoeostasis and blood pressure control. Using the human epithelial colon cell line SW-620, reverse transcriptase-polymerase chain reaction and enzyme kinetic analysis indicated expression of only 11beta-HSD2 (Km for cortisol 66 nmol/l). Bradykinin (10(-8) to 10(-12) mol/l), frusemide (10(-4) to 10(-9) mol/l), benzamiloride hydrochloride (10(-5) to 10(-10) mol/l) and atrial natriuretic peptide (10(-6) to 10(-10) mol/l) had no effect on 11beta-HSD2 expression. Using a range of concentrations of angiotensin II (2x10(-8) to 2x10(-5) mol/l) a significant reduction in activity was seen but only at supra-physiological concentrations, [e.g. 2x10(-6) mol/l at 4 h pretreatment: 36.7+/-2.0 pmol cortisone. h-1.mg-1 (mean+/-S.E.M.) compared with 45.1+/-1.7 pmol.h-1.mg-1 in control; P<0.05]. The angiotensin-converting enzyme inhibitors captopril, enalapril, lisinopril, perindopril, quinapril and trandolapril at 10(-7) mol/l, but not fosinopril, significantly increased 11beta-HSD2 activity after pretreatment for 16 or 24 h (P<0.05-P<0.01 compared with control). No effects were seen at 4 h pretreatment. Hydrochlorothiazide (10(-7) mol/l) significantly decreased 11beta-HSD2 activity (P<0.05 compared with control) at 4 h pretreatment. Commonly used diuretics, atrial natriuretic peptide and physiological concentrations of angiotensin II and bradykinin do not alter 11beta-HSD2 activity. In contrast, a series of angiotensin-converting enzyme inhibitors significantly increase 11beta-HSD2 activity in vitro. This may explain how intrarenal infusions of angiotensin-converting enzyme inhibitors increase renal sodium excretion independent of circulating concentrations of angiotensin II. The interaction between angiotensin-converting enzyme inhibitors and 11beta-HSD2 may be an additional mechanism by which the former can lower blood pressure.
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PMID:Regulation of 11beta-hydroxysteroid dehydrogenase type 2 by diuretics and the renin-angiotensin-aldosterone axis. 1033 75

The objective of the present study was to analyze the influence of the I/D polymorphism of the ACE gene on the outcome of microalbuminuria in essential hypertensive patients who were receiving antihypertensive treatment. One hundred thirty-six essential hypertensive patients who were <50 years old and had never previously received treatment with antihypertensive drugs were included in the study. During a 3-year period, patients received nonpharmacological treatment consisting of moderate salt restriction and a low-calorie diet they were obese, with or without a regimen of antihypertensive drugs based on beta-blockers or ACE inhibitors. Hydrochlorothiazide was added when necessary to maintain the blood pressure goal of <135/85 mm Hg. At the beginning of the study and at yearly intervals, systolic and diastolic blood pressures (SBP and DBP, respectively), 24-hour urinary albumin excretion (UAE), renal function, and biochemical profile measurements were made. The insertion/deletion (I/D) polymorphism of the ACE gene was determined through the use of polymerase chain reaction. The variables used in the statistical analysis were the measurements at the start of the study and the increase or decrease detected during the follow-up, estimated as individual specific regression line slope values. At baseline, no differences in blood pressure or UAE values were observed among genotypes. Likewise, the genotype or allele frequency was not significantly different between normoalbuminurics and microalbuminurics. After the 3 treatment years, significant reductions in SBP, DBP, and UAE were found (SBP 151.6+/-17.3 reduced to 137.2+/-14.3 mm Hg, P<0.001; DBP 96.6+/-8.9 reduced to 84.5+/-9.8 mm Hg, P<0.001; UAE 36.7+/-71.5 reduced to 28.3+/-78.6 mg/24 h, P<0. 05). The slopes of these parameters over time did not differ significantly among genotypes. The slope of SBP was the main factor related to the slope of logUAE (P<0.003). A significant positive correlation coefficient between the SBP and logUAE slopes was observed for the DD patients (r=0.57, P<0.0001) but was absent in patients carrying the I allele (II r=-0.03, P=NS; I/D r=0.01, P=NS). Follow-up studies should be used to achieve a better understanding of the impact of candidate gene polymorphisms on the development of hypertension-induced organ damage. Assessment of the I/D polymorphism of the ACE gene may identify subjects who require a greatly lowered blood pressure to prevent organ damage and to reduce hypertension-associated complications and death.
Hypertension 2000 Jan
PMID:Influence of the I/D polymorphism of the angiotensin-converting enzyme gene on the outcome of microalbuminuria in essential hypertension. 1064 47

Hyperuricemia is associated with hypertension and vascular disease, but whether this represents a causal relationship or an epiphenomenon remains unknown. We recently reported a model of mild hyperuricemia in rats that results in increased blood pressure and mild renal fibrosis. In this study, we examined the effect of hyperuricemia on the renal vasculature. Rats fed 2% oxonic acid and a low-salt diet for 7 wk developed mild hyperuricemia (1.8 vs. 1.4 mg/dl, P < 0.05), hypertension [147 vs. 127 mmHg systolic blood pressure (SBP), P < 0.05], and afferent arteriolar thickening, with a 35% increase in medial area (P < 0.05). Allopurinol or benziodarone prevented the hyperuricemia, hypertension, and arteriolopathy. Hydrochlorothiazide treatment did not prevent the hyperuricemia or arteriolopathy despite controlling blood pressure. In contrast, the arteriolopathy and hypertension were prevented by both enalapril and losartan. Uric acid also directly stimulated vascular smooth muscle cell proliferation in vitro, and this was partially inhibited by losartan. Thus hyperuricemia induces a renal arteriolopathy in rats that is blood pressure independent and involves the renin-angiotensin system.
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PMID:Hyperuricemia induces a primary renal arteriolopathy in rats by a blood pressure-independent mechanism. 1199 15

ACE inhibition reduces plasminogen activator inhibitor-1 (PAI-1), a risk factor for myocardial infarction, whereas the effect of angiotensin receptor antagonism on PAI-1 is uncertain. The present study compares the time course of effects of ACE inhibition and angiotensin type 1 (AT1) receptor antagonism on morning plasma PAI-1 antigen. Blood pressure and endocrine, metabolic, and fibrinolytic variables were measured in 20 insulin-resistant (defined by fasting glucose >8.3 mmol/L, body mass index >28 kg/m2, or fasting serum triglyceride > or =2.8 mmol/L) hypertensive subjects (mean age, 47.9+/-2.1 years) (1) before and after 1 week of hydrochlorothiazide 12.5 mg/d, and (2) before and 1, 3, 4, and 6 weeks after addition of ramipril (escalated to 10 mg/d) or losartan (escalated to 100 mg/d). Hydrochlorothiazide decreased systolic (P=0.011) and diastolic (P=0.019) pressure. Ramipril (from 133.6+/-5.1/94.5+/-2.4 to 127.0+/-3.1/91.4+/-3.3 mm Hg) or losartan (from 137.0+/-3.9/93.1+/-2.9 to 123.7+/-2.6/86.4+/-2.1 mm Hg) further reduced systolic (P=0.009) and diastolic (P=0.037) pressure. The pressure effects of the 2 drugs were similar. Hydrochlorothiazide increased plasma PAI-1 (P=0.013) but not tissue-type plasminogen activator (tPA) (P=0.431) antigen. Addition of either ramipril or losartan significantly decreased plasma PAI-1 antigen (P=0.046). However, the effect of losartan on PAI-1 antigen was not sustained throughout the 6-week treatment period, such that there was a significant drugxtime interaction (P=0.043). tPA antigen decreased during either ramipril or losartan (P=0.032), but tPA activity decreased only during losartan (P=0.018). Short-term interruption of the renin-angiotensin-aldosterone system by either ACE inhibition or AT1 receptor antagonism decreases PAI-1 antigen, but the duration of this effect is greater for ACE inhibition than for AT1 receptor antagonism.
Hypertension 2002 Dec
PMID:ACE inhibition versus angiotensin type 1 receptor antagonism: differential effects on PAI-1 over time. 1246 70

1. Hydrochlorothiazide mixture (HCTM) is widely used in China for the treatment of hypertension. This mixture consists of hydrochlorothiazide, triamterene, reserpine, hydralazine and chlordiazpoxide, with small (one-third to one-fifth of normal) doses of each drug. The present study was designed to investigate the effects of this mixture on blood pressure, blood pressure variability (BPV), baroreflex sensitivity (BRS) and end-organ damage in spontaneously hypertensive rats (SHR). 2. The HCTM was mixed in the rat chow and rats were treated for 4 months. After treatment, rats were catheterized and their blood pressure, BPV and BRS were measured in the conscious state. Organ damage was examined after these measurements had been completed. 3. It was found that HCTM not only decreased blood pressure and BPV, but also ameliorated impaired BRS in SHR. The HCTM had an obvious effect on organ protection in SHR. 4. The HCTM prevented left ventricular hypertrophy and this effect was mainly related to a decrease in systolic blood pressure. The effects of HCTM on preventing renal atrophy were mainly determined by BRS. Baroreflex sensitivity was the most important determinant for predicting organ damage in HCTM-treated SHR. 5. In conclusion, long-term treatment of rats with HCTM prevented hypertensive organ damage. Restoration of arterial baroreflex function contributes to organ protection in SHR treated in the long term with HCTM.
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PMID:Restoration of arterial baroreflex function contributes to organ protection in spontaneously hypertensive rats treated with long-term hydrochlorothiazide mixture. 1254 53

Data from the Third National Health and Nutrition Examination Survey (NHANES III) demonstrate that only 11% of people with diabetes who are treated for high blood pressure achieve the blood pressure goal of <130/85 mm Hg recommended in the sixth report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI). The current study tests the hypothesis that initial therapy with a fixed-dose combination will achieve the recommended blood pressure goal in patients with type 2 diabetes faster than conventional monotherapy. This randomized, double-blind, placebo-controlled study had as a primary end point achievement of blood pressure <130/85 mm Hg. Participants (N=214) with hypertension and type 2 diabetes received either amlodipine/benazepril 5/10 mg (combination) or enalapril 10 mg (conventional) once daily for 4 weeks, titrated to 5/20 mg/day or 20 mg/day, respectively at this time, if target blood pressure was not achieved. Hydrochlorothiazide (HCTZ) 12.5 mg/day was added for the final 4 weeks, if target blood pressure was still not reached. Time from baseline to achieve blood pressure <130/85 mm Hg was shorter in the combination group (5.3+/-3.1 weeks combination vs. 6.4+/-3.8 weeks conventional; p=0.001). At 3 months, more participants in the combination group achieved treatment goal (63% combination vs. 37% conventional; p=0.002). Data analysis at 3 months comparing blood pressure control rates between the fixed-dose combination group (without HCTZ) to the conventional group (receiving HCTZ) showed an even greater disparity in blood pressure goal achievement (87% combination without HCTZ vs. 37% conventional group with HCTZ; p=0.0001). We conclude that initial therapy with a fixed-dose combination may be more efficacious than conventional monotherapy approaches for achieving blood pressure goals in the diabetic patient. A fixed-dose combination approach appears as safe as the current conventional approaches.
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PMID:Achieving goal blood pressure in patients with type 2 diabetes: conventional versus fixed-dose combination approaches. 1282 83

Kinzalkomb marketed in Belgium by Bayer is a fixed combination of telmisartan 80 mg and hydrochlorothiazide 125 mg for the treatment of hypertension. New guidelines for the treatment of hypertension were recently released both in Europe and the United States (see article by J.M. Krzesinski in this issue). They offer the choice of using a fixed biotherapy even as first line treatment. Hydrochlorothiazide at low dose is a frequent component of such biotherapies: it is efficacious and secure. Telmisartan is a highly selective blocker of angiotensin II AT1 receptors ("sartans"); it is at least as effective as the classical antihypertensive agents; thanks to its half-life, the longest of all sartans', it provides adequate antihypertensive coverage throughout the whole 24-hour postdose interval and particularly over the last 6 hours of the dosage interval. Its tolerability profile is equivalent to placebo. The combination telmisartan-hydrochlorothiazide is more effective than each agent alone at lowering blood pressure; furthermore telmisartan possesses a potassium-sparing effect that when the two drugs are coadministered attenuates the kaliuretic effect of hydrochlorothiazide. Various large trials are currently under way (ONTARGET, TRANSCEND, PROFESS, PROTECTION, DETAIL). These studies which together involve some 50,000 patients will hopefully help to further specify the role of telmisartan in condition which require an intervention on the renin-angiotensin system.
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PMID:[Kinzalkomb, a fixed telmisartan-hydrochlorothiazide combination for the treatment of hypertension]. 1462 54

Thiazide diuretics are one of the preferred pharmacologic treatments for hypertension. Hydrochlorothiazide and chlorthalidone have been the 2 most commonly used diuretics in major clinical trials. Treatment guidelines and compendia often consider these 2 drugs interchangeable agents within the class of thiazide or thiazide-like diuretics. Many sources list them as equipotent. Despite these beliefs, there is some suggestion that cardiovascular outcomes are not necessarily the same with these 2 drugs. We conducted a literature search from 1960 to 2003 to identify studies that evaluated the pharmacokinetic and blood pressure-lowering effects of these 2 agents. There are significant pharmacokinetic and pharmacodynamic differences between these diuretics. Chlorthalidone is approximately 1.5 to 2.0 times as potent as hydrochlorothiazide, and the former has a much longer duration of action. Whether these pharmacokinetic and pharmacodynamic features cause differences in outcomes is not known.
Hypertension 2004 Jan
PMID:Hydrochlorothiazide versus chlorthalidone: evidence supporting their interchangeability. 1463 21

Hydrochlorothiazide and other thiazide-like diuretics are considered as a first-line drug for initial therapy in uncomplicated arterial hypertension [1]. There are several reports [2-6] of thiazide-induced cholecystitis, but here we report a case of serious hepatotoxicity associated with hydrochlorothiazide treatment.
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PMID:Hydrochlorothiazide induced hepato-cholestatic liver injury. 1527 38

Hypertension and diabetes mellitus are closely interrelated and coexist in as many as two-thirds of patients with type 2 diabetes. The consequent risk of such an association is an accelerated development of atherosclerotic cardiovascular disease and nephropathy complications.In choosing an antihypertensive agent, effectiveness needs to be accompanied by favourable metabolic, cardioprotective, and nephroprotective properties. Given the multifactorial nature of hypertension, the approach that has gained widespread agreement is treatment with more than one agent. Agents with different mechanisms of action increase antihypertensive efficacy because of synergistic impacts on the cardiovascular system. Combination therapy allows the use of lower doses of each antihypertensive agent which accounts for the excellent tolerability of combination products.The aim of the present study is to quantify the efficacy of combination therapy of Eprosartan 600 mg respectively Ramipril 5 mg with low-dose Hydrochlorothiazide and Moxonidine on blood pressure levels in patients with essential hypertension and associated diabetes mellitus type 2.The use of monotherapy (Eprosartan or Ramipril) followed by addition of low-dose Hydrochlorothiazide as second agent and of Moxonidine as a third agent will be individualized to the severity of hypertension in the particular patient and to his/her degree of response to current treatment.
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PMID:A novel approach to treatment of hypertension in diabetic patients - a multicenter, double-blind, randomized study comparing the efficacy of combination therapy of Eprosartan versus Ramipril with low-dose Hydrochlorothiazide and Moxonidine on blood pressure levels in patients with hypertension and associated diabetes mellitus type 2 - rationale and design [ISRCTN55725285]. 1546 84


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