Cardiovascular counterregulation during sympathetic inhibition in normal subjects and patients with mild hypertension.
- 1 November 1983
- journal article
- research article
- Published by Wolters Kluwer Health in Hypertension
- Vol. 5 (6), 873-880
- https://doi.org/10.1161/01.hyp.5.6.873
Abstract
The influence of agents that inhibit sympathetic nerve activity on cardiovascular responsiveness, as related to major pressor factors, has been unclear. Therefore, these components were evaluated in 11 normal subjects and 13 patients with mild essential hypertension, before and after 4 wk of sympathetic neuron blockade with the agent debrisoquine. In these normal and mildly hypertensive subjects, sympathetic neuron blockade caused approximately similar decreases in urinary and supine or upright plasma norepinephrine (NE) levels (average changes in the 2 groups, -41% and -45%, respectively; P < 0.05 to < 0.005), the chronotropic dose of isoproterenol (-45% and -38%), and the NE pressor dose (-47% and -51%, P < 0.01), while the relationship between NE-induced changes in blood pressure and concomitant plasma NE concentrations was displaced to the left (P < 0.01). Supine heart rate was also lowered (-10% and -8%, P < 0.05). Compared to the orthostatic variations during placebo conditions, mild postural decreases in blood pressure were apparent in both normal and hypertensive groups (-8% and -7.5%). However, supine blood pressure was unchanged following debrisoquine treatment. Other parameters were also not consistently changed, such as: total blood volume, exchangeable body Na, urinary electrolytes, plasma epinephrine, renin and angiotensin II (AII) levels, the pressor dose of infused AII, and the relationship between AII-induced changes in blood pressure and plasma AII measured before and during AII infusion. The reduction in sympathetic outflow during sympathetic neuron blockade may elicit a hyperresponsiveness of .alpha.- and .beta.-adrenergic receptors that is equal in normal subjects and patients with mild essential hypertension.This publication has 21 references indexed in Scilit:
- Calcium and blood pressure regulation in normal and hypertensive subjects.Hypertension, 1983
- Antihypertensive mechanism of diuretic treatment with chlorthalidone. Complementary roles of sympathetic axis and sodiumKidney International, 1983
- Correction of altered noradrenaline reactivity in essential hypertension by indapamide.Heart, 1981
- Pressor factors and cardiovascular pressor responsiveness in borderline hypertension.Hypertension, 1981
- Pathogenic and Therapeutic Significance of Cardiovascular Pressor Reactivity as Related to Plasma Catecholamines in Borderline and Established Essential HypertensionClinical and Experimental Hypertension, 1980
- Cardiovascular and endocrine profile of adrenergic neurone blockade in normal and hypertensive manAmerican Journal Of Medicine, 1979
- Simultaneous radioenzymatic determination of plasma and tissue adrenaline, noradrenaline and dopamine within the femtomole rangeLife Sciences, 1976
- Plasma renin and blood pressure during treatment with methyldopaThe American Journal of Cardiology, 1974
- Estimation of Angiotensin II Concentration in Human Plasma by Radioimmunoassay. Some Applications to Physiological and Clinical StatesEuropean Journal of Clinical Investigation, 1971
- The effects of guanethidine and of alpha-methyldopa on the digital circulation in hypertensionAmerican Heart Journal, 1965