Journal article
Aging‐induced abnormalities in baroreflex and feed‐forward control of heart rate at rest and during spontaneous activity in mice
The FASEB journal, Vol.20(5), pp.A1209-A1209
03/2006
DOI: 10.1096/fasebj.20.5.A1209-c
Abstract
The baroreflex (BR) opposes blood pressure (BP) variability, while feed‐forward (FF) mechanisms (eg, central sympathetic drive) enhance BP variability by driving BP, heart rate (HR), and vascular resistance in the same direction. Locomotor activity may shift the balance between BR and FF control. The goal of this study was to determine effects of aging on BR and FF control of HR and BP regulation in conscious freely‐behaving mice. BP and pulse interval (PI) were measured by telemetry in young (17±2 weeks, n=9) and old (126±2 weeks, n=10) mice. A software was used to analyze sequences of three or more consecutive arterial pulses where systolic BP and PI changed in the same (BR sequences) and opposite (FF sequences) direction (r2>0.85). At rest, old mice exhibited significantly (P<.05) higher mean BP (115±4 vs. 100±3 mmHg) and systolic BP variability (36±9 vs. 13±2 mmHg2), and lower BR gain (0.5±0.1 vs. 2.4±0.8 ms/mmHg). In young mice, locomotor activity increased the number of BR sequences/10min from 18±8 to 64±21 (+46±17) and the number of FF sequences from 8±6 to 32±11 (+24±8) (P<.05). In contrast, activity did not increase the number of BR (−2±11) or FF (+1±7) sequences in old mice. BR gain remained suppressed in old mice during activity (0.5±0.1 vs. 1.9±0.4 ms/mmHg). We conclude that aging decreases BR gain at rest and during activity, and abolishes the activity‐induced increase in BR engagement observed in young mice. The loss of BR dominance over FF mechanisms likely contributes to increases in BP and BP variability with aging.
(HL14388)
Details
- Title: Subtitle
- Aging‐induced abnormalities in baroreflex and feed‐forward control of heart rate at rest and during spontaneous activity in mice
- Creators
- Veronica Accioly Peotta - Univ of IowaHarald M Stauss - Univ of IowaEric Lazartigues - Univ of IowaCarol A Whiteis - Univ of IowaRasna Sabharwal - Univ of IowaRobin L Davisson - Univ of IowaFrancois M Abboud - Univ of IowaMark W Chapleau - Vet Aff Med Ctr
- Resource Type
- Journal article
- Publication Details
- The FASEB journal, Vol.20(5), pp.A1209-A1209
- Publisher
- Federation of American Societies for Experimental Biology
- DOI
- 10.1096/fasebj.20.5.A1209-c
- ISSN
- 0892-6638
- eISSN
- 1530-6860
- Number of pages
- 1
- Language
- English
- Date published
- 03/2006
- Academic Unit
- Iowa Neuroscience Institute; Health and Human Physiology; Cardiovascular Medicine; Internal Medicine; Molecular Physiology and Biophysics
- Record Identifier
- 9984072081502771
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