Faculty Collaboration Database

Hypertension induced by high salt intake in absence of volume retention in reduced renal mass rats. Am J Physiol 1994 Nov;267(5 Pt 2):H1707-12

Date

11/11/1994

Pubmed ID

7977802

DOI

10.1152/ajpheart.1994.267.5.H1707

Scopus ID

2-s2.0-0028004262 (requires institutional sign-in at Scopus site)   17 Citations

Abstract

Reduction of renal mass (RRM) combined with a high-salt diet results in volume retention, a rise of cardiac output, and hypertension. The present studies were designed to determine whether prevention of volume retention would alter the rise of mean arterial pressure (MAP) in RRM rats given high salt. Rats were studied in a modified metabolic cage to permit continuous determination of total body weight (TBW). In group 1, NaCl was increased from 1 to 14.5 meq/day and delivered isotonically. In group 2, NaCl was increased while TBW was servo-controlled to a constant level. Group 3 was also servo-controlled, but rats received an intravenous infusion of an arginine vasopressin V1 antagonist throughout the study. MAP in group 1 rose 24 mmHg by day 4 of high salt with a parallel increase of TBW of 26 g. In group 2, MAP rose 48 mmHg by day 4 of high salt, while TBW was controlled to within 0.6% of control body weight. With inhibition of vasopressin V1 receptors (group 3), MAP rose 39 mmHg. Nearly equivalent amounts of NaCl were retained in all groups, which was associated with no change of plasma Na in group 1 but an increase of nearly 7 meq/ml in groups 2 and 3. Hematocrit fell nearly 9% in groups 2 and 3 compared with a 4% reduction in group 1. The results suggest that under conditions where net retention cannot occur, high salt intake increases MAP by an osmotically driven fluid transfer from cells, which results in an even greater expansion of blood volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Author List

Cowley AW Jr, Skelton MM, Papanek PE, Greene AS

Authors

Allen W. Cowley Jr PhD Professor in the Physiology department at Medical College of Wisconsin
Paula Papanek PhD, MPT, LAT, FACSM Associate Professor & Director of Exercise Science in the Exercise Science & Physical Therapy department at Marquette University

MESH terms used to index this publication - Major topics in bold

Analysis of Variance
Animals
Arginine Vasopressin
Blood Pressure
Body Weight
Cardiac Output
Hematocrit
Hypertension
Infusions, Intravenous
Male
Nephrectomy
Rats
Rats, Sprague-Dawley
Sodium, Dietary