ПРЕДОТВРАЩЕНИЕ АТРОФИИ ТЕНОТОМИРОВАННОЙ КАМБАЛОВИДНОЙ МЫШЦЫ КРОЛИКА ПРИ ДЕНЕРВАЦИИ. НЕЙРОТРОФИЧЕСКОЕ ВЛИЯНИЕ

Abstract

In the 1930—1940s R. G. Leibson and A. G. Ginеtsinsky with colleagues carried out the experiments were it was shown that the changes in tenotomized rabbit soleus muscle are completely eliminated if the nerve is cut at the same time. The authors concluded that atrophy from inactivity is not a passive process, but it is an active result of neural influences which are carried out by the ventral roots of sciatic nerve. The nature of these influences has not been studied and nervous control is not clear. The present study was carried out on 2-month old Californian rabbits to confirm the described phenomenon and to investigate the assumed neurotrophic mechanisms. The morphological signs of atrophy and degeneration of tenotomized rabbit muscles, muscle fiber death of and growth of connective tissue were eliminated on day 11 of exposure by simultaneous Achilles tenotomy. The effect of colchicine application on the tenotomized muscle was almost the same as denervation (10 mM solution was applicated at the sciatic nerve for 10 min), but in the case of colchicine the degenerative changes were more pronounced. Denervation of the tenotomized muscle or colchicine application maintained the fast fiber cross-sectional area at the level of intact control. Sciatic nerve denervation or colchicine application prevented the rise in soleus muscle TrkB and TrkС expression and altered some neurotrophin expression. Denervation with tenotomy decreased TrkB mRNA expression by 3.4 times (p < 0.05), TrkC — by 3.2 times (p < 0.05), NT3-by 3.4 times (p < 0.05) compared with the tentotomized contralateral limb, colchicine with tenotomy — by 3.6 and 2.9 times respectively (p < 0.05).