Ciliary neurotrophic factor stimulates in vivo myotube formation in mice

It is known that ciliary neurotrophic factor (CNTF) administration reduces the atrophy observed with denervation, suggesting its role as a trophic factor for muscle cells. At the present, we studied the effects of 'in vivo' CNTF administration on the regenerative capacity of skeletal muscle fibres. Adult mice had their extensor digitorium longus muscle subjected to a denervation-devascularization lesion. CNTF (0.5 ng/microl) was administered using osmotic pumps implanted subcutaneously in unrestrained mice. CNTF was delivered into the muscle's region at a rate of 1 microl/h from 1 to 8 days after denervation. The results show that CNTF increased the number of regenerating myofibres by day 4. From day 7 on, the values seen on control and CNTF-treated groups were not significantly different. Our results show that 'in vivo' CNTF administration accelerates myotube differentiation.