The Effect of Clonidine on Plasma Renin Activity in Human Hypertension

Abstract

1.Clonidine inhibits plasma renin activity (PRA) in hypertensive patients, 2. This effect is not related to sodium retention, but is probably due to inhibition especially when administered for more than 4 days. of the basal sympathetic activity.

Antihypertensive β-Blockade and the Renin-Angiotensin System

“…In consequence, cardioselective blockers including atenolol and metoprolol (7) as well as non-cardioselective blockers including oxprenolol (71), propranolol (7,20,26), Sandoz LL 21945 (48) and most recently Sandoz LT 31200 (49) lowered renin effectively. Our results are in accordance with most of the other studies in which (3-blocking agents such as practolol (50), atenolol (51), oxprenolol (46,52), timolol (53), alprenolol (28) and bunolol (54), acebutolol (26), nadolol (55) have been report ed to lower renin. Other authors, however, maintain that some of these drugs do not suppress renin (56,57).…”

Postural Changes of Plasma Renin Activity after Renal Transplantation

“…The inhibitory effect of the beta-receptor blocking drug on postural increase of PRA supports the hypothesis that the sympathetic nervous system is a primary mechanism controlling renin secretion during postural changes (Gordon et al, 1967;Salvetti et al, 1971 ;Meurer, 1971;Salvetti et al, 1973;Tobert et al, 1973). As reported, an increase of PRA in response to the upright posture can be found in patients with renal homotransplants (Lewis et al, 1966;Greene et al, 1968;Nielsen et al, 1970;Cooke et al, 1973;Beckerhoff et al, 1974).…”

“…Catecholamines, whjch can stimulate renin secretion (Gordon et al, 1967;Tanigawa, Allison & Assaykeen, 1972;Vandongen, Peart & Boyd, 1973), may be increased in the urine and plasma during orthostasis (Gordon et al, 1967;Esler & Nestel, 1973;Molzahn, Dissmann, Halim, Lohmann & Oelkers, 1972), and neural regeneration has been reported to occur as early as the twentyeighth day in human renal transplants (Gazdar & Dammin, 1970). Because the stimulating effect of the sympathetic nervous system and of catecholamines on renin secretion is counteracted by the administration of a beta-receptor blocking agent (Salvetti et al, 1971 ;Tanigawa et al, 1971 ;Meurer, 1971 ;Michelakis & McAllister, 1972;Vandongen et al, 1973;Salvetti et al, 1973;Tobert, Slater, Fogelman, Lightman, Kurtz CSC Payne, 1973), the response of PRA to a beta-receptor blocking agent may be an indirect way of assessing their role in regulating renin secretion.…”

“…There is increasing evidence that the sympathetic nervous system takes part in the regulation of renin secretion during orthostasis (Gordon, Kiichel, Liddle & Island, 1967 Baccini, 1973). The finding that patients with renal homotransplantation may show a significant postural increase of PRA"' (Lewis, Blaufox & Hickler, 1966;Greene, Vander & Kowalczyk, '1968;Nielsen, Clausen & Jensen, 1970;Cooke, Ruiz-Maza, Kowarski, Migeon & Walker, 1973;Beckerhoff, Uhlschmidt, Vetter, Armbruster & Siegenthaler, 1974), although indicating that other mechanisms may be involved, does not exclude a possible role of the circulating catecholamines or of the sympathetic nervous system.…”

Clinical Significance of Plasma Renin Activity in Human Renovascular Hypertension

“…The role of the sympathetic nervous system, which is one of the factors controlling renin secretion (Salvetti, Arzilli. Russo & Zucchelli, 1971 ;Davis, 1973;Vandongen, Peart & Boyd, 1973), may be indirectly assessed by the inhibition of renin secretion by a 8-receptor-blocking agent (Salvetti et a/., 1971;Tanigawa, Allison & Assaykeen, 1971;Meurer, 1971;Michelakis & McAllister, 1972;Salvetti, Arzilli & Baccini, 1973 We have therefore assessed the clinical significance of PRA in renovascular patients by three different approaches: (i) measuring PRA in peripheral venous blood, (ii) observing the PRA response to a breceptor-blocking agent (oxprenolol), and (iii) measuring PRA in peripheral and renal veins during simultaneous sampling.…”