AJP - Regulatory, Integrative and Comparative Physiology, Vol 268, Issue 4 884-R888, Copyright © 1995 by American Physiological Society
Reduced lactate transport in denervated rat skeletal muscle
K. J. McCullagh and A. Bonen
Department of Anatomy and Physiology, Trinity College, Dublin, Ireland.
The purpose of this study was to investigate the effect of the neural
regulation of contractile activity on lactate transport in skeletal muscle.
Contractile activity of the rat soleus muscle was abolished by denervating
the hindlimb muscles in one leg (3 days) while the sham-operated
contralateral hindlimb muscles served as a control. Three days after
surgery, lactate transport into the soleus muscle was measured in vitro,
using incubated soleus muscle strips. Lactate uptake by the denervated
soleus muscle was reduced compared with control (P < 0.05). The
diffusive component of lactate transport was unaltered by denervation (P
> 0.05). These results translated into a reduction in lactate
carrier-mediated transport capacity (-68%) in the denervated soleus (P <
0.05). These studies indicate that loss of contractile activity results in
a decrement of lactate transport, which is probably due to a reduction in
the number of lactate carriers in the sarcolemma. Our results suggest that
the inherent activity of the muscle is important in maintaining the lactate
transport system.
