AJP - Regulatory, Integrative and Comparative Physiology, Vol 269, Issue 1 222-R225, Copyright © 1995 by American Physiological Society
Autonomic nervous system activity in weight gain and weight loss
L. J. Arone, R. Mackintosh, M. Rosenbaum, R. L. Leibel and J. Hirsch
Laboratory of Human Behavior and Metabolism, Rockefeller University, New York, New York 10021-6399, USA.
Studies in both animals and humans indicate that the autonomic nervous
system (ANS) responds to changes in systemic energy balance. In the present
study, ANS response to weight change was examined by sequential blockade of
cardiac autonomic innervation with parasympathetic (atropine) and
sympathetic (esmolol) blockers. Change in heart period (interbeat interval)
from baseline after atropine defined the amount of parasympathetic control
(PC), and the subsequent change after esmolol defined the amount of
sympathetic control (SC). In nonobese subjects, weight gain to 10% above
initial body weight resulted in a decrease in PC and an increase in SC, and
conversely, weight loss to 10% below initial weight resulted in an increase
in PC and a decrease in SC. In obese subjects, weight loss resulted in the
same pattern of changes in PC and SC. The major changes were in the
parasympathetic arm of the ANS. These findings support the hypothesis that
the ANS acts to oppose weight change.
