AJP - Regulatory, Integrative and Comparative Physiology, Vol 256, Issue 4 939-R945, Copyright © 1989 by American Physiological Society
Body weight of rats following area postrema ablation: effect of early force-feeding
N. J. Kenney, J. N. Kott, N. Tomoyasu, A. J. Bhatia, A. S. Ruiz and M. M. McDowell
Department of Psychology, University of Washington, Seattle 98195.
This study examined the effect of intragastric force-feeding of a milk diet
on body weights of rats with lesions of the area postrema/caudal medial
nucleus of the solitary tract (AP/cmNTS). Force-feeding was conducted over
the first 10 days after the ablation. Body weight was monitored both during
and after force-feeding. Food intake was measured during all ad libitum
feeding periods. During force-feeding, rats with AP/cmNTS lesions gained
weight at the same rate as force-fed sham-lesioned rats or sham-lesioned
rats that voluntarily ingested an equal amount of the milk. When returned
to ad libitum feeding, lesioned rats that had been force-fed were not
hypophagic and did not lose weight. Body weights of such rats remained
above those of lesioned rats that were not force-fed and similar to those
of nonlesioned rats throughout this study. Despite their normal weights,
preliminary analysis indicated that body fat of the force-fed lesioned rats
may have been reduced. These findings suggest that the effects of AP/cmNTS
ablation are multiple and that reduction of body weight need not be the
primary effect of such lesions.
