title: Increase of neurite-promoting activity for spinal neurons in muscles of 'paralysé' mice and tenotomised rats.
abstract: Various lines of evidence from in vivo and in vitro experiments suggest that muscle-derived factors may enhance the survival and axonal outgrowth of spinal neurons. Our previous results using cultures of embryonic spinal neurons showed that denervation of skeletal muscle increased levels of a neurite-promoting activity in soluble muscle extracts. Here, two other experimental models in which muscle activity was also lowered were investigated. The mutant mouse 'paralysé' exhibits a spontaneous regression of motor nerve endings, with concomitant paralysis. In 'paralysé' mutant muscle extracts, specific neurite-promoting activity was up to 10-fold higher than in extracts prepared from control littermates. Tenotomy is known to retard the regression of polyneuronal motor innervation in skeletal muscle from neonatal rats. Three days after operation, levels of neurite-promoting activity were increased 2-fold with respect to total protein. These results suggest that skeletal muscle activity might regulate the synthesis of molecules affecting nerve growth.
mesh_terms: D000367:Age Factors; D000818:Animals; D051379:Mice; D008818:Mice, Neurologic Mutants / Q000378:metabolism*; D009119:Muscle Contraction; D009132:Muscles / Q000032:analysis*; D009414:Nerve Growth Factors / Q000032:analysis*; D010243:Paralysis / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D013116:Spinal Cord / Q000254:growth & development*; D013710:Tendons / Q000601:surgery
chemical_list: D009414:Nerve Growth Factors