American journal of hypertension
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The objective of this study was to characterize the neurogenic contraction and relaxation of the human gastroepiploic artery and to determine whether the responses are mediated by nitric oxide (NO) from neural or endothelial origin. ⋯ The results provide functional evidence that NO is released by autonomic nerves of the human gastroepiploic artery. We hypothesize that the release of NO from both endothelial and neurogenic origin may modulate resistance of the human gastroepiploic artery. Dysfunction in any of these sources of NO should be considered in some form of vasospasm.
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Numerous studies have emphasized the important role of altered Ca(2+) channel function in hypertension. We previously showed that Ca(2+) currents measured in myocytes isolated from both Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) small mesenteric arteries closely correlated with systolic blood pressure (BP) during normal development. The purpose of the present experiments was to determine whether antihypertensive therapy with an angiotensin converting enzyme inhibitor normalizes Ca(2+) channel function in SHR myocytes along with BP. ⋯ The I(K) measured from holding potentials of -60 and -20 mV were significantly smaller in treated SHR and WKY compared to their untreated counterparts, as was the component of I(K) measured in the presence of 100 nmol/L iberiotoxin. These results show that ramipril treatment decreases arterial pressure and Ca(2+) channel function in SHR as expected but unexpectedly also decreases I(K) in both WKY and SHR. These results suggest that angiotensin may have a BP independent effect on ion channel function in arterial smooth muscle.
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Comparative Study
Ethnic differences in electrocardiographic criteria for left ventricular hypertrophy: the LIFE study. Losartan Intervention For Endpoint.
African Americans have greater precordial QRS voltages than whites, with concomitant higher prevalences of electrocardiographic (ECG) left ventricular hypertrophy (LVH) and lower specificity of ECG LVH criteria for the identification of anatomic hypertrophy. However, the high mortality associated with LVH in African American patients makes more accurate ECG detection of LVH in these patients a clinical priority. ⋯ When standard, non-ethnicity-specific thresholds for the identification of LVH are used, Sokolow-Lyon and 12-lead voltage overestimate and Cornell voltage underestimates the presence and severity of LVH in African American relative to white individuals. However, these apparent ethnic differences in test performance disappear when ethnic differences in the distribution of ECG LVH criteria are taken into account. These findings demonstrate that ethnicity-specific ECG criteria can equalize detection of anatomic LVH in African American and white patients.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Darusentan: an effective endothelinA receptor antagonist for treatment of hypertension.
The antihypertensive efficacy and safety of darusentan, a new selective endothelin, antagonist was investigated. ⋯ These data, the first, suggest the therapeutic benefit of selective endothelinA receptor antagonism in human hypertension.
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Patients with obstructive sleep apnea syndrome (OSAS) are subject to an increased cardiovascular morbidity including systemic hypertension. Little is known about the effects of treatment with nasal continuous positive airway pressure (CPAP) on systemic hypertension. ⋯ Obstructive sleep apnea syndrome contributes, at least in part, to the development of systemic hypertension, and CPAP may improve BP values in treated OSAS patients. Predictors of a beneficial CPAP effect on BP are a high heart rate and a high pulse pressure before treatment.