Effect of the new centrally acting antihypertensive agent rilmenidine on endothelial and platelet function in essential hypertension

Abstract

The aim of the study was to investigate the effect of therapy by rilmenidine on endothelial and platelet function in 23 patients with the early stages of untreated essential hypertension. The measurements were carried out before therapy, after 1 week of placebo administration, after 1 week, after 1 month and after 3 months of therapy. After 1 week of therapy both systolic (SBP) and diastolic blood pressure (DBP) were reduced (P Ͻ 0.001) all over the study period. Plasma thrombomodulin (TM) and von Willebrand factor (vWF) as indicators of endothelial dysfunction, and plasma ␤-thromboglobulin (␤TG) as an indicator of in vivo platelet activation, were investigated. Fibrinogen as a risk factor for vascular changes was also assayed. Platelet aggregation without stimulation (spontaneous, SPA) and induced by adre-

Haemorheological, platelet and endothelial factors in essential hypertension

“…The three case-control studies [3][4][5] have extended previous research by showing an increased hyperviscosity and endothelial dysfunction among patients with hypertension who had no concomitant cardiovascular risk factors. Unlike some studies that have included severe hypertensives, all three examined either mild or newly diagnosed hypertensives who were generally middle-aged.…”

“…Hlubocká et al 4 noted significantly higher levels of ICAM-1, vWf, and endothelin-1 among the hypertensives compared to the normotensives, whilst no significant difference was found in levels of E-selectin, P-selectin, fibrinogen, tissue plasminogen activator (tPA) and plasminogen activator inhibitor type 1 (PAI-1). The hypertensives in the study by Ciuffetti et al 3 showed significantly higher blood vis- Table 1 Haemorheological and endothelial factors found to differ significantly between hypertensives and normotensives in three studies [3][4][5] von Willebrand factor Beta thromboglobulin Soluble thrombomodulin P-selectin Intracellular cell adhesion molecule-1 Endothelin-1 Blood viscosity Plasma viscosity Fibrinogen Red cell filterability Leucocyte filterability Red cell deformability Red cell aggregation Platelet aggregation cosity, plasma viscosity, fibrinogen and soluble Pselectin levels, together with significantly increased red blood cell filterability, unfractionated leucocyte filterability, erythrocyte deformability and erythrocyte aggregation. Furthermore, among the hypertensives, similar differences were seen for both the low and high capillary density subgroups.…”

“…Furthermore, among the hypertensives, similar differences were seen for both the low and high capillary density subgroups. In comparison with healthy subjects, Remková and Kratochvíl'ová 5 found that platelet aggregation and levels of βTG, TM, and vWf were significantly elevated among the hypertensives.…”

“…[3][4][5] In addition, Ciuffetti et al 3 further divided their hypertensives into two groups based on skin capillary density (which may contribute to the increase in total peripheral resist-Journal of Human Hypertension ance among hypertensives). Moreover, Hlubocká et al 4 examined the effects of antihypertensive treatment with quinapril (an angiotensin-converting enzyme (ACE) inhibitor) on cell adhesion molecules, whilst Remková and Kratochvíl'ová 5 reported the impact of rilmenidine (a second-generation sympatholytic) therapy on endothelial and platelet function.…”

“…These include (a) some form of platelet receptor binding mechanism, (b) a direct reduction in sympathetic nervous system activity which, in turn, has a favourable metabolic effect on lipids and insulin sensitivity, and (c) regulation of catecholamine release. 5 The enhanced total peripheral resistance observed among hypertensives could partly be caused by a reduction in capillary density, although the clinical significance of this capillary rarefaction is unknown. Ciuffetti et al 3 showed that hypertensives with a capillary density above the median exhibit higher levels of plasma viscosity, haematocrit and fibrinogen.…”