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Open‐loop static characteristics of the carotid sinus baroreflex in rats fed a high‐fat diet
Author(s) -
Abe Chikara,
Iwata Chihiro,
Morita Hironobu
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.689.2
Subject(s) - baroreflex , carotid sinus , medicine , blood pressure , endocrinology , chemistry , anesthesia , heart rate
It is still controversial whether high‐fat diet‐induced obesity attenuates the function of the carotid sinus baroreflex. To examine this, we employed open‐loop baroreflex analysis. Rats were fed a high‐fat diet from the 4th to 13th week, and then separated into 2 groups (Lean and Fat) by the body weight. The body weight in Fat group was significantly higher than that in Lean group (474 ± 8 vs 521 ± 4 g), while there was no difference in the baseline arterial pressure (AP) under free moving condition. In the open‐loop baroreflex analysis, the AP and renal sympathetic nerve activity (SNA) was measured in response to stepwise increment of isolated carotid sinus pressure (CSP) from 60 to 180 mmHg. The SNA was normalized by the maximal response induced by the ischemia. In the Fat group, CSP‐SNA relationship (neural arc) shifted to a higher SNA and slope of SNA‐AP relationship (peripheral arc) decreased compared with Lean group. Consequently, there was no difference in the operating point between Fat and Lean group (109 ± 4 vs 104 ± 6 mmHg). This result indicates that the sympathoexcitation‐induced AP increase was buffered by decrease in gain of peripheral arc in Fat group.