Chronically-altered body protein levels following lateral
hypothalamic lesions in rats.
Hirvonen, Matt D., and Richard E. Keesey.
University of Wisconsin, Madison, WI 53706
APStracts 2:0318R, 1995.
Rats maintaining reduced body weights following lesions of the lateral
hypothalamus (LH) are characterized by smaller body protein masses.
Two experiments were conducted to determine whether or not this
reduced protein mass is actively defended. In the first, it was found
that LH rats induced to overeat and restore body weight to the level
of nonlesioned controls markedly increased their body fat without
significantly increasing body protein. That is, LH rats at normal
body weights were notably obese. In the second experiment body
protein losses in LH rats produced by food restriction were both
relatively small and proportionally the same as those seen in
similarly-restricted nonlesioned controls. These observations
demonstrate that LH rats retain the capacity for preserving body
protein when challenged by either under- or over-nutrition. The
apparently irreversible reduction in the body protein mass thus
appears to be the result of a specific lean tissue down-regulation
induced by lateral hypothalamic damage.
Received 19 June 1995; accepted in final form 20 October 1995.
APS Manuscript Number R374-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 30 November 95