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Mineralocorticoid receptor in NTS stimulates salt intake during 4th ventricular infusions of aldosterone
Author(s) -
Koneru Bhuvaneswari,
Bathina Chandra Sekhar,
Cherry Brandon,
Franzke Michelle,
Mifflin Steve
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.694.1
Subject(s) - aldosterone , mineralocorticoid receptor , medicine , endocrinology , stimulation , mineralocorticoid , receptor , ventricle , chemistry
The purpose of this study was to determine if neurons within the NTS that possess the mineralocorticoid receptor (MR) play a role in aldosterone stimulation of salt intake. Adult WKY rats received microinjections into the NTS of a small, hairpin RNA for the MR (shRNA; n=9) or a scrambled RNA (scRNA; n=8). After the viral construct injections, aldosterone‐filled osmotic mini‐pumps were implanted subcutaneously and connected to tubing within the 4th ventricle to infuse aldosterone at a rate of 20ng/h. Prior to and after surgeries, rats had ad libitum access to food and two graduated drinking bottles filled with distilled water and 0.3M NaCl and salt intake expressed as 100 × the ratio of 0.3M NaCl intake to total fluid intake. Prior to surgeries, basal salt intake was 4.7% ± 2.9% in the scRNA group and 3.91% ± 2.6% in the shRNA group. 24 days post‐surgery salt intake was 20.6% ± 2.9% in the scRNA group and 4.3% ± 2.8% in the shRNA group. Post‐mortem immunohistochemistry revealed a significant reduction in the number of NTS neurons exhibiting immunoreactivity for the MR (scRNA 33 ± 2 cells/section; shRNA 23 ± 1 cells/section; p=.008). These results indicate 4th ventricular infusions of aldosterone stimulate salt intake and that at least part of the stimulation of salt intake during 4th ventricular infusions of aldosterone is mediated by hindbrain NTS neurons that possess the MR.