Akute kombinierte Alpha- und Betarezeptorenblockade bei essentieller Hypertonie: Wirkungen auf Blutdruck, Nierenfunktion, Renin und Aldosteron

Abstract

In seven patients with uncomplicated essential hypertension the effects of an acute alpha-adrenergic blockade, alone and combined with a chronic beta-adrenergic blockade, on blood pressure, renal function as measured by standard clearance methods, plasma renin activity, and plasma aldosterone were evaluated. Acute alpha-adrenergic blockade with phentolamine (20 mg by intravenous infusion) significantly enhanced the antihypertensive effect of chronic beta-adrenergic blockade with slow-oxprenolol (160 mg/ day X 14 days) (- 14.5% verus - 7.4% for pulse pressure, - 12.4% versus - 6.0% for diastolic pressure, 2 alpha less than 0.05). Under combined adrenergic blockade renal plasma flow increased, glomerular filtration rate and filtration fraction decreased (2 alpha less than 0.05 each), whereas the fractional clearances of sodium, potassium, free water, and solute load remained unchanged. The activation of the renin-angiotensin-axis, elicited by alpha-adrenergic blockade alone, was suppressed by the preceding beta-adrenergic blockade. These findings demonstrate a favourable antihypertensive action of a combined blockade of alpha- und beta-adrenergic receptor sites without untoward side effects on renal function or the renin-angiotensin-axis.

The inhibiting effect of trilostane on adrenal steroid synthesis: Hormonal and morphological alterations induced by subchronic trilostane treatment in normal rats

“…The mechanism of this effect is obscure; it might be explained by an intracellular accumulation of potassium, by sodium depletion, or by other yet unknown factors [10,14,16,17]. In our study, only propranolol induces a significant salt depletion, whereas the effect of indomethacin on electrolyte excretion is not significant.…”