Faculty Collaboration Database

Effect of chronic salt loading on adenosine metabolism and receptor expression in renal cortex and medulla in rats. Hypertension 1999 Jan;33(1 Pt 2):511-6

Date

02/04/1999

Pubmed ID

9931157

DOI

10.1161/01.hyp.33.1.511

Scopus ID

2-s2.0-0032899717 (requires institutional sign-in at Scopus site)   91 Citations

Abstract

Previous studies have shown that chronic salt loading increased renal interstitial adenosine concentrations and desensitized renal effects of adenosine, a phenomenon that could facilitate sodium excretion. However, the mechanisms responsible for the increased adenosine production and decreased adenosine response are poorly understood. This study examined the effects of the dietary high salt intake on adenosine metabolism and receptor expression in the renal cortex and medulla in Sprague Dawley rats. Fluorescent high-performance liquid chromatography analyses were performed to determine adenosine levels in snap-frozen kidney tissues. Comparing rats fed a normal (1% NaCl) versus high salt (4% NaCl) diet, renal adenosine concentrations in rats fed a high salt diet were significantly higher (cortex: 43+/-3 versus 85+/-4, P<0.05; medulla: 183+/-4 versus 302+/-8 nmol/g wet tissue, P<0.05). Increased adenosine concentrations were not associated with changes in the 5'-nucleotidase or adenosine deaminase activity, as determined by quantitative isoelectric focusing and gel electrophoresis. Western blot analyses showed that a high salt diet (4% NaCl for 3 weeks) downregulated A1 receptors (antinatriuretic type), did not alter A2A and A2B receptors (natriuretic type), and upregulated A3 receptors (function unknown) in both renal cortex and medulla. The data show that stimulation of adenosine production and downregulation of A1 receptors with salt loading may play an important role in adaptation in the kidney to promote sodium excretion.

Author List

Zou AP, Wu F, Li PL, Cowley AW Jr

Author

Allen W. Cowley Jr PhD Professor in the Physiology department at Medical College of Wisconsin

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

5'-Nucleotidase
Adenosine
Adenosine Deaminase
Animals
Down-Regulation
Gene Expression Regulation
Kidney Cortex
Male
Organ Specificity
Rats
Rats, Sprague-Dawley
Receptor, Adenosine A2A
Receptor, Adenosine A2B
Receptors, Purinergic P1
Reference Values
Sodium, Dietary
Up-Regulation