Behavior of the renin-angiotensin-aldosterone system and vasopressin secretion in patients with renovascular hypertension or small kidney
Wieçek, A.; Kokot, F.
Zeitschrift für die Gesamte Innere Medizin und ihre Grenzgebiete 40(6): 172-176
1985
ISSN/ISBN: 0044-2542 PMID: 3890386 Document Number: 247427
In 11 hypertensive subjects with unilateral and 8 patients with bilateral renal artery stenosis as well as in 7 hypertensive patients with a so-called small kidney and in 33 normotensive subjects the behaviour of the plasma osmolality, plasma aldosterone and vasopressin level (AVP) as well as of the plasma renin activity (PRA) were estimated twice. First after the supply of a normal salted diet (100-120 mmol NaCl/d) and 8 hr overnight recumbency, and a second time after NaCl restriction (20 mmol NaCl/d) for 3 days and 3-4 hr upright position. In hypertensive patients with bilateral renal artery stenosis and with a "small kidney" significantly elevated AVP-levels were found both before and after NaCl-restriction in the diet as compared with normotensives. In contrast to normotensive subjects in hypertensive patients no significant correlation was found between plasma osmolality and AVP levels. No correlation was also found between plasma AVP-levels and blood pressure as well as between AVP-levels and PRA (with the exception of patients with unilateral renal artery stenosis). From the result obtained in this study the existence of a positive feedback mechanism between the renin-angiotensin-aldosterone system and the AVP-secretion and the participation of AVP in the pathogenesis of the hypertension caused by reduced blood supply of the kidneys is questioned.