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Reversal of microvascular rarefaction and reduced renal mass hypertension. Hypertension 1997 Jul;30(1 Pt 1):120-7 PMID: 9231831

Abstract

This study examined the microcirculatory and renin-angiotensin system changes following the reversal of hypertension in reduced renal mass rats. Nine-week-old Sprague-Dawley reduced renal mass rats were placed on a low or high sodium diet for 4 or 8 weeks or a combination of 4 weeks of high sodium followed by 4 weeks of low sodium. Blood pressure was directly measured during the development of hypertension and its reversal. Plasma renin activity, angiotensin-converting enzyme activity, and angiotensin II concentrations were measured throughout the experiment. The cremaster and hindlimb muscles were removed, and microvascular density was determined by quantitative stereology. Four weeks of high sodium increased blood pressure (152+/-7 mm Hg) and reduced microvessel density (13.7%). Reduced renal mass hypertension was rapidly reversed after the rats were returned to a low sodium diet (124+/-7 mm Hg after 3 days), and microvascular density returned to control levels. After 4 weeks of high sodium, circulating plasma renin activity and angiotensin II fell by 94% and 82%, respectively. Plasma angiotensin-converting enzyme activity was increased after 2 weeks of high sodium but returned to control levels after 4 weeks of high sodium. This study demonstrates that microvascular density is reduced in reduced renal mass hypertensive rats following exposure to high sodium diet and this is associated with a fall in circulating plasma renin activity and angiotensin II levels. Microvascular density can return to normal levels after a reactivation of the circulating renin-angiotensin system. This study provides further evidence for the hypothesis that modulation of the renin-angiotensin system is important in the regulation of microvascular structure.

Author List

Rieder MJ, Roman RJ, Greene AS

Author

Andrew S. Greene PhD Interim Vice Chair, Chief, Professor in the Biomedical Engineering department at Medical College of Wisconsin

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

Analysis of Variance
Angiotensin II
Animals
Diet, Sodium-Restricted
Hypertension, Renal
Kidney
Male
Microcirculation
Muscles
Peptidyl-Dipeptidase A
Rats
Renin
Renin-Angiotensin System
Sodium, Dietary
Time Factors



View this publication's entry at the Pubmed website PMID: 9231831
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