Nociceptive atrophy of the rat soleus muscle induced by bone fracture: a morphometric study. Zachaova, Gisela, Helena Knotkova-Urbancova, Pavel Hnik, and Tomas Soukup. Institute of Physiology, Academy of Sciences of the Czech Republic, V[acute]ide[grave]osk[acute]a 1083, Prague, Czech Republic
APStracts 3:0469A, 1996.
Reflex atrophy of the soleus muscle induced by ipsilateral metatarsal bone fracture in Sagatal anesthetized adult male rats was studied using 2-D stereological methods seven days after the operation. When compared with contralateral solei, the wet weight of the experimental soleus muscles was decreased by 24% and the area of the entire muscle section by 29%. In atrophied solei, the number of type 1 fibers was lower by 8% resulting in lower total number of fibers (by 6%). This indicates that slow motor units might be more sensitive to nociceptive stimulation. However, with respect to the fiber area, the reflex atrophy induced by metatarsal bone fracture in the rat soleus muscle resembles simple atrophy after 7 days, as the mean muscle fiber area was decreased by 26% with no significant difference between atrophy of type 1 and type 2a fibers (by 27.3% and 23.0% respectively).

Received 6 February 1995; accepted in final form 30 September
1996.
APS Manuscript Number A134-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996