Newsletter 6 - Febbraio 2009
Ruolo degli antagonisti dei recettori dell' angiotensina II e dei calcio antagonistiGender-related difference in arterial elastance during exercise in patients with hypertension.
Hypertension 2008 Apr;51(4):1163-9 (ISSN: 1524-4563)
Park S; Ha JW; Shim CY; Choi EY; Kim JM; Ahn JA; Lee SW; Rim SJ; Chung N
Division of Cardiology, Cardiovascular Center, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemoon-gu, Seoul, Korea 120-752.
Exercise intolerance and heart failure with preserved ejection fraction are common in females. Recently, arterial stiffness has been suggested to be a significant contributor in the development of heart failure. How gender difference affects arterial stiffening and its response to exercise is not well known. We hypothesized that arterial elastance index during exercise would be more abnormal in females with hypertension than males. Arterial elastance index was estimated as arterial end systolic pressure/stroke volume controlled for body surface area and was measured at rest and during graded supine bicycle exercise (25 watts, 3-minute increments) in 298 patients with hypertension (149 males; 149 females; mean age, 59). The subjects were divided into 2 groups by gender. Exercise duration was significantly shorter in females compared to males (692+/-222 versus 483+/-128 seconds, P <0.001). Although arterial elastance index at baseline was significantly higher in males, the magnitude of incre ... [Continua]
Effects of valsartan or amlodipine on endothelial function and oxidative stress after one year follow-up in patients with essential hypertension.
Clin Exp Hypertens 2008 Apr;30(3):267-76 (ISSN: 1525-6006)
Hirooka Y; Kimura Y; Sagara Y; Ito K; Sunagawa K
Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan. hyoshi@cardiol.med.kyushu-u.ac.jp.
Endothelial function is impaired in hypertensive patients. Decreased nitric oxide production and increased oxidative stress are involved in this abnormality. The aim of the present study was to evaluate whether endothelial function and oxidative stress differ following long-term antihypertensive treatment with an angiotensin type 1 receptor blocker, valsartan, or a calcium channel blocker, amlodipine, in patients with essential hypertension. Hypertensive patients were treated with valsartan (80-160 mg/day) or amlodipine (5-10 mg/day) for one year (n = 9 for each). The baseline blood pressure was similar between groups, and the magnitude of the decreases in blood pressure did not differ during treatment at three months, six months, or one year. Endothelial function and oxidative stress markers were examined before and after treatment. Endothelial function, assessed by flow-mediated vasodilation, was significantly improved in hypertensive patients treated with valsartan (5.8 +/- 1.2 to 10.7 +/- 1.4 %, p < 0.01) but not in ... [Continua]
Effects of angiotensin II blockade on inflammation-induced alterations of pharmacokinetics and pharmacodynamics of calcium channel blockers.
Br J Pharmacol 2008 Jan;153(1):90-9 (ISSN: 0007-1188)
Hanafy S; Dagenais NJ; Dryden WF; Jamali F
Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada.
BACKGROUND AND PURPOSE: Inflammation elevates plasma verapamil concentrations but diminishes pharmacological response. Angiotensin II is a pro-inflammatory mediator. We examined the effect of angiotensin II receptor blockade on the pharmacokinetics and pharmacodynamics of verapamil, as well as the binding properties and amounts of its target protein in calcium channels, in a rat model of inflammation. EXPERIMENTAL APPROACH: We used 4 groups of male Sprague-Dawley rats (220-280 g): inflamed-placebo, inflamed-treated, control-placebo and control-treated. Inflammation as pre-adjuvant arthritis was induced by injecting Mycobacterium butyricum on day 0. From day 6 to 12, 30 mg kg(-1) oral valsartan or placebo was administered twice daily. On day 12, a single oral dose of 25 mg kg(-1) verapamil was administered and prolongation of the PR interval measured and plasma samples collected for verapamil and nor-verapamil analysis. The amounts of the target protein Ca(v)1.2 subunit of L-type calcium channels in heart was measured by Western blotting and ligand binding with (3)H-nitrendipine. K ... [Continua]
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