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Progression of autonomic changes in heart rate control during development of obesity
Author(s) -
Carroll Joan F,
Winterrowd Kim,
Heymann Abraham
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.970.4
Subject(s) - overeating , medicine , metoprolol , heart rate , obesity , endocrinology , autonomic nervous system , blockade , balance (ability) , blood pressure , receptor , physical therapy
Both acute overeating and chronic obesity increase heart rate (HR), but it is unclear whether autonomic mechanisms of HR control are altered during the progression from acute overeating to chronic obesity. This study used pharmacologic blockade to determine parasympathetic (PSNS) and sympathetic (SNS) influences on HR control during 1 wk of acute overeating vs 12 wks of developing obesity. PSNS and SNS influences on HR control were estimated using blockade by scopolamine (SCOP) and metoprolol (METO), respectively. HR after double blockade represented intrinsic HR. Compared with controls, acutely overfed rabbits had a reduced HR response to SCOP, and a similar HR response to METO. Intrinsic HR tended to be higher (p=0.08). Calculations of autonomic balance indicated reduced PSNS influence (p=0.03). In contrast, obese rabbits had similar increases in HR after SCOP, greater decreases in HR after METO, and increased intrinsic HR. Calculations of autonomic balance indicated both reduced PSNS influence and increased SNS influence, resulting in a significant shift toward SNS control of HR (p=0.04). These data suggest that 1 wk of acute overeating negatively impacted PSNS control of HR, while chronic obesity negatively altered both SNS and PSNS control of HR.