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Dose‐dependent effects of DOCA treatment on cardiovascular function and brain sodium content in the rat
Author(s) -
Abrams Joanna M,
Dubinsky Janet M,
Guzman Pilar Ariza,
Osborn John W
Publication year - 2008
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.22.1_supplement.1210.15
Subject(s) - endocrinology , hypothalamus , saline , medicine , chemistry , sodium , organic chemistry
Rats were uninephrectomized, implanted with transmitters for the measurement of arterial pressure (AP), and given either water or 0.9% NaCl to drink. Fluid ingestion (FI) and Na balance were calculated daily. Rats were implanted with a silicone pellet containing 0, 50, or 100 mg DOCA, resulting in 4 groups: control (n=6) saline: 0 mg DOCA + 0.9% NaCl (n=8) 50 mg: 50 mg DOCA + 0.9% NaCl (n=9) 100 mg: 100 mg DOCA + 0.9% NaCl (n=9) DOCA treatment increased AP, FI, and Na balance (p<0.05). Although 50 mg and 100 mg rats had identical increase in AP, 100 mg rats consumed 2‐fold more saline. Positive Na balance was observed in both DOCA groups, but not in control animals; however, only 100 mg rats showed a significant increase in Na balance as compared to saline rats. We analyzed Na content of several brain regions, including hypothalamus, brainstem, cortex, and, as a measure of overall brain Na content, homogenized half‐brain. Na content was constant across all regions with the exception of the hypothalamus. DOCA treatment increased Na content in the hypothalamus in a dose‐dependent manner. Our results indicate that while increasing DOCA dose from 50 mg to 100 mg has no effect on AP, other variables showed dose‐sensitive modulation. In particular, brain handling of increasing sodium load may be region‐dependent, and the hypothalamus may play a unique role in driving responses to DOCA‐salt treatment. HL064178.