Journal of Neuroscience, Vol 10, 3516-3523, Copyright © 1990 by Society for Neuroscience
Motor nerve regulates muscle extracellular matrix proteoglycan expression
R Fadic, E Brandan and NC Inestrosa
Department of Cell and Molecular Biology, Faculty of Biological Sciences, Catholic University of Chile, Santiago.
Denervation of rat leg muscles caused a 2-3-fold increase in 35S- sulfate
and 3H-glucosamine incorporation into proteoglycans of the muscle
extracellular matrix. The size of the proteoglycans and the
glycosaminoglycan chain length and degree of sulfation were unchanged.
Because the rate of degradation of proteoglycans was also unchanged by
denervation, we infer that denervation increases proteoglycan synthesis.
Muscle reinnervation restored the original rate of synthesis of
proteoglycans. Paralysis of innervated muscle caused increased
incorporation of sulfate comparable to that seen in denervation. Thus motor
nerve activity appears to regulate the level of proteoglycans in the muscle
extracellular matrix.