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)

The effects of doxazosin (alpha-1-inhibitor) and enalapril (ACE-inhibitor) on blood pressure and exercise stress test were assessed in 10 hypertensive patients (8 M, 2 F, age 58 +/- 9 years) with coronary artery disease and exertional myocardial ischemia. A single blind, cross-over, placebo controlled trial was performed. Placebo was administered for 2 periods of 2 weeks, doxazosin and enalapril for at least 3 weeks. The sequence of the active drugs was randomized and the single daily dose, obtained by titration, was 7 +/- 5 mg for doxazosin and 18 +/- 13 mg for enalapril. Blood pressure measurements and treadmill tests (Bruce protocol) were performed at the end of each period. Rest systolic and diastolic pressures after placebo were respectively 173 +/- 15 and 106 +/- 9 mmHg and were reduced to 153 +/- 11 and 93 +/- 12 mmHg (p less than 0.05) after doxazosin and to 150 +/- 24 and 93 +/- 12 mmHg (p less than 0.05) after enalapril. Total exercise time was 473 +/- 91 s after placebo and increased to 545 +/- 84 s (p less than 0.05) after doxazosin and 529 +/- 100 s (p less than 0.05) after enalapril. Time to 1 mm ST depression (ST1) was 297 +/- 102 s after placebo and increased to 414 +/- 96 s (p less than 0.05) after doxazosin and to 396 +/- 133 s (p less than 0.05) after enalapril. Double product at peak exercise and at ST1 were respectively 26.3 +/- 2.8 and 22.1 +/- 2.8 x 10(3) and remained unchanged after enalapril and doxazosin. Peak exercise diastolic blood pressure was 107 +/- 5 mmHg after placebo, was reduced to 94 +/- 15 mmHg (p less than 0.05) after doxazosin and was unchanged after enalapril (101 +/- 10 mmHg, NS). Thus, doxazosin and enalapril induced a comparable decrease of rest blood pressure and a similar increase of exercise time in hypertensive patients with exertional myocardial ischemia. Doxazosin but not enalapril reduced exercise diastolic blood pressure.
 ...
PMID:[Comparative effects of doxazosin and enalapril in patients with arterial hypertension and exercise-induced acute myocardial ischemia]. 168 51

Thirty-seven essential hypertensives received placebo for 3 weeks followed by nifedipine retard (n = 14) or enalapril (n = 13) or doxazosin (n = 10) as monotherapy for 6 weeks and attended study days to evaluate the effects of placebo, first dose, and chronic (1-6 weeks) treatment. On each study day, pressor responses to i.v. infusions of phenylephrine (PE) and angiotensin II (AII) were measured 1.5-3 h after drug administration and the derived PD20 values (dose required to increase mean blood pressure by 20 mm Hg) compared. Each treatment produced comparable reductions in BP. Nifedipine significantly attenuated the pressor responses to AII and PE: for AII, the mean PD20 (ng/kg/min) increased from 8.2 (placebo) to 9.9 (first dose), 13.9 (1 week), and 17.4 (6 weeks). Pressor responsiveness to both AII and PE was unchanged following enalapril: for PE, the mean PD20 (micrograms/kg/min) was 2.1 (placebo), 1.5 (first dose), and 1.5 (6 weeks). Doxazosin produced rightward shifts of the PE pressor dose-response curves but had no effect on responses to AII. The relationship between the simultaneous BP and HR changes during the infusion of PE was used as an index of cardiac baroreflex activity. In contrast to enalapril and doxazosin, which had no effect, nifedipine reduced the slope of the HR/BP relationship from -0.62 (placebo) to -0.38 (first dose) and -0.31 beats/min/mm Hg (6 weeks). For comparable reductions in BP, doxazosin only affects adrenergic mechanisms whereas nifedipine affects both adrenergic and non-adrenergically mediated vasoconstriction. The ACE inhibitor enalapril had no effect on pressor responses to AII and PE.
 ...
PMID:Vascular pressor responses in treated and untreated essential hypertension. 169 73

1. Isolated perfused male Sprague-Dawley rat tail artery segments were used to investigate interactions between the alpha-1-adrenoceptor antagonist, doxazosin, and the angiotensin converting enzyme (ACE) inhibitor, enalaprilat, using phenylephrine (PE) as the alpha 1-adrenoceptor agonist. 2. In concentrations of up to 10(-5) mol/L, enalaprilat had no effect on arterial responses to PE. 3. Doxazosin produced a concentration-dependent competitive alpha 1-adrenoceptor antagonism, yielding a mean pA2 value of 8.72. 4. In the continuous presence of 10(-6) mol/L enalaprilat, doxazosin with a pA2 value of 9.10 was a 2.4-fold more potent alpha 1-adrenoceptor antagonist than in the absence of enalaprilat. 5. These results are interpreted to indicate that endogenously produced angiotensin II can modulate the activity of alpha 1-adrenoceptors in vascular smooth muscle.
 ...
PMID:An in vitro study of interactions between doxazosin and enalaprilat at vascular alpha 1-adrenoceptors. 256 3

Although the pathology of essential hypertension is still unclear, studies have shown that doxazosin, a selective alpha 1-inhibitor, is able to effectively control mild-to-moderate hypertension. The aim of these two, noncomparative studies was to evaluate the efficacy and toleration of doxazosin when used as monotherapy and in combination with other antihypertensive agents. In study I, 154 patients with standing and sitting diastolic blood pressures (DBPs) ranging from 95 to 115 mm Hg were treated with once-daily doxazosin (1 to 8 mg) as monotherapy for 12 weeks. Both sitting and standing blood pressures were significantly reduced by doxazosin monotherapy. Target DBP of less than or equal to 90 mm Hg was achieved in 86% of patients after 12 weeks of therapy with doxazosin, and there was no change in heart rate. Cholesterol and triglyceride levels were significantly decreased by doxazosin, but there was no change in glucose levels. Minor side effects were seen in 17.5% of patients, and 2.6% discontinued therapy. In study II, 65 patients with DBPs ranging from 95 to 115 mm Hg on existing antihypertensive therapies were concomitantly treated with doxazosin (1 to 8 mg) once daily for 12 weeks. Target DBPs of less than or equal to 90 mm Hg was achieved in 71% of patients after 12 weeks of therapy with doxazosin. There was no change in heart rate throughout the treatment period, and plasma cholesterol, triglyceride, and glucose levels remained essentially unchanged. Three patients, each receiving a beta-blocker, a diuretic, and doxazosin, were withdrawn because of side effects. Minor side effects, which were considered drug related were seen in 21% of patients. Doxazosin is a drug with good antihypertensive efficacy and is well tolerated as monotherapy and in combination with beta-blockers, thiazide diuretics, angiotensin converting enzyme inhibitors, and various combinations of these drugs.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Control of coronary heart disease risk factors with doxazosin as monotherapy and in combination therapy. 290 47