Daily spontaneous running attenuated the central gain of the arterial baroreflex.

Title

Daily spontaneous running attenuated the central gain of the arterial baroreflex.

Creator

Chen C Y; DiCarlo S E; Scislo T J

Publisher

The American journal of physiology

Date

1995
1995-02

Description

Exercise training attenuates arterial baroreflex function. Mechanisms responsible may include an attenuated aortic baroreceptor reactivity (afferent mechanisms) and/or an attenuated central baroreflex gain. We tested the hypothesis that the aortic baroreceptor reactivity and/or central gain is attenuated by daily spontaneous running (DSR). Eighteen anesthetized Sprague-Dawley rats (11 control and 7 DSR) were tracheotomized and instrumented with femoral venous and right carotid arterial catheters. Electrodes were placed around the left aortic depressor nerve and the lumbar sympathetic trunk. Eight to thirteen weeks of DSR were associated with a 20% increase in heart weight-to-body weight ratio (2.83 +/- 0.04 vs. 3.39 +/- 0.10 g/kg; P \textless 0.001) and resting bradycardia (413 +/- 6 vs. 384 +/- 10 beats/min; P = 0.01). DSR reduced the central gain of the baroreflex regulation of heart rate (0.210 +/- 0.046 vs. 0.005 +/- 0.021 beats.min-1.%-1; P = 0.004) during decreases in arterial pressure. However, the reactivity of aortic baroreceptor afferents and the central gain of the baroreflex control of lumbar sympathetic nerve activity were not different in control and DSR rats. Thus DSR reduced the central gain of the arterial baroreflex regulation of heart rate without changing the reactivity of aortic baroreceptor afferents. We conclude that afferent mechanisms are not responsible for the training-induced reduction in arterial baroreflex function.

Subject

Animal; Animals; Arteries/*physiology; Baroreflex/*physiology; Brain/*physiology; Female; Male; Motor Activity/*physiology; Physical Conditioning; Rats; Sprague-Dawley

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

H662–669

Issue

2

Volume

268

Citation

Chen C Y; DiCarlo S E; Scislo T J, “Daily spontaneous running attenuated the central gain of the arterial baroreflex.,” NEOMED Bibliography Database, accessed May 6, 2021, https://neomed.omeka.net/items/show/4617.

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