BLUNTED PRESSURE NATRIURETIC RESPONSE IN THE OLD RAT - PARTICIPATION OF THE RENAL NERVES

Citation
S. Masilamani et al., BLUNTED PRESSURE NATRIURETIC RESPONSE IN THE OLD RAT - PARTICIPATION OF THE RENAL NERVES, American journal of kidney diseases, 32(4), 1998, pp. 605-610
Citations number
27
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Urology & Nephrology
Journal title
ISSN journal
0272-6386
Volume
32
Issue
4
Year of publication
1998
Pages
605 - 610
Database
ISI
SICI code
0272-6386(1998)32:4<605:BPNRIT>2.0.ZU;2-K
Abstract
With advancing age, there is a generalized reduction in the ability of the kidney to generate a natriuretic response and, in addition, the i ncidence of salt-sensitive hypertension increases. One event that coul d link these changes is a defect that develops in the pressure natriur esis response of the old kidney. To test this possibility, we conducte d studies on the anesthetized, male Sprague-Dawley rat to determine th e effect of abrupt alterations of renal perfusion pressure (RPP) on ur inary sodium excretion (UNaV). Young (3- to 5-month old), middle-aged (11- to 13-month-old), and old (18- to 20-month-old) rats were studied , and RPP was varied by clamping the aorta during the infusion of a co cktail of vasoactive hormones that suppressed the activity of endogeno us factors. The gain of the pressure natriuresis relationship was seve rely attenuated in the old rat compared with the young and middle-aged rats. This blunting of the pressure natriuresis relationship in the o ld rat was partially attenuated by acute renal denervation. This effec t was not associated with marked alterations in the filtered load of s odium, implying that aging is associated with a loss of the tubular ep ithelial response to an acute change in RPP, These observations sugges t that the blunted pressure natriuresis may have a role in the increas ed incidence of salt-sensitive hypertension and that increased renal n erve activity may have a contributory role. (C) 1998 by the National K idney Foundation, Inc.