Effects of antihypertensive therapy on human α- and β-adrenoceptors


    loading  Checking for direct PDF access through Ovid

Abstract

The present study was designed to investigate the role of plasma catecholamines in the regulation of adrenoceptors in human hypertension. Thirty-three patients with newly detected essential hypertension were treated for 4 weeks with either nifedipine (2 x 20 mg/day), hydergine ( 2 x 2 mg/day), or both (20 and 2 mg/day, respectively, twice daily each), which lowered blood pressure equally well. Plasma noradrenaline increased during nifedipine, decreased during hydergine and was unaltered during the combination therapy. Lymphocyte β2-adrenoceptor density decreased by similar amounts, independent of whether blood pressure was normalized by treatment with nifedipine or hydergine. Platelet α2 -adrenoceptor density, however, decreased during nifedipine, slightly increased during hydergine and was unchanged during the combination treatment. We conclude that lymphocyte β2-adrenoceptors of hypertensive patients are not regulated primarily by plasma catecholamines but rather by a distinct factor associated with the extent of blood pressure elevation. The density of platelet α2 -adrenoceptors, however, appears to be dynamically regulated by catecholamines.

    loading  Loading Related Articles