AJP - Cell Physiology, Vol 258, Issue 4 C723-C729, Copyright © 1990 by American Physiological Society
Exercising mammals synthesize stress proteins
M. Locke, E. G. Noble and B. G. Atkinson
Faculty of Physical Education, University of Western Ontario, London, Canada.
Spleen cells, peripheral lymphocytes, and soleus muscles were removed from
male Sprague-Dawley rats that had been run on a treadmill (24 m/min) for
either 20, 40, or 60 min or to exhaustion (86 +/- 41 min) and were labeled
in vitro with [35S]methionine at 37 degrees C. Similar tissues from
nonrunning control rats were labeled in vitro at either 37 or 43 degrees C
(heat shock). Fluorographic analyses of one- and two-dimensional
polyacrylamide gel electrophoretic separations of the proteins from cells
and tissues of exercised rats demonstrate the new or enhanced synthesis of
proteins of approximately 65, 72, 90, and 100 kDa. Although synthesis of
these proteins is low or not detectable in tissues from control rats
labeled at 37 degrees C, they are prominent products of similar tissues
labeled under heat-shock conditions (43 degrees C) and, in fact, correspond
in Mr and pI with the so-called heat-shock proteins. These results suggest
that exercise is a sufficient stimulus to induce or enhance the synthesis
of heat shock and/or stress proteins in mammalian cells and tissues.
