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Systemic and Renal‐Specific Sympathoinhibition in Obesity Hypertension
Author(s) -
Liu Boshen,
Iliescu Radu,
Lohmeier Thomas
Publication year - 2011
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.25.1_supplement.1078.2
Subject(s) - baroreflex , medicine , blood pressure , denervation , heart rate , mean arterial pressure , stimulation , endocrinology , anesthesia , sympathetic nervous system , cardiology
The natural activation of the baroreflex has been shown to chronically suppress renal sympathetic nerve activity (RSNA) and promote sodium excretion. Therefore, we compared the relative antihypertensive effects of bilateral electrical stimulation of the carotid baroreflex to bilateral renal denervation (DNX) in dogs with obesity hypertension. After control measurements, the diet was supplemented with beef fat for 4 weeks until body weight increased to ~ 150% of control. There were increases in mean arterial pressure (MAP) from 100±3 to 116±1 mmHg and heart rate (HR) from 84±4 to 121±5 bpm. Subsequently, baroreflex activation reduced blood pressure to control levels within 24 hours. Moreover, this antihypertensive response was sustained for the 7 days of stimulation (day 7, MAP= 100±3 mmHg). HR decreased substantially, falling to 99±3 bpm on day 7. Both MAP and HR returned to pre‐stimulation hypertensive levels during the recovery period. Next, the dogs were subjected to DNX. Within 48 hours, MAP fell to normotensive levels, whereas HR remained elevated. Fourteen days after DNX, MAP and HR were 100±3 mmHg 119±5 bpm, respectively. These results emphasize the critical role of increased sympathetic activity in the pathogenesis of obesity hypertension and suggest that sustained suppression of RSNA may be the essential response mediating the long‐term blood pressure lowering effects of baroreflex activation. In addition, by improving autonomic control of cardiac function, a clear advantage of baroreflex activation over renal denervation is that the former may diminish the likelihood of adverse cardiac events.