[Trophic effect of ciliary neurotrophic factor on denervated skeletal muscle]

The trophic effect of CNTF on skeletal muscle atrophy and dysfunction reduced by denervation was investigated in SD rats.

SD rats transected sciatic nerve in right side hind limbs were injected CNTF subcutaneously for 20 days. Skeletal muscle wet weights, protein contents, muscle fiber cross-sectional areas, contract properties and degree of hind limb abnormalities were observed in the rats.

(1) Administrating of CNTF (0.2 mg/kg) in sciatic nerve transected SD rats attenuated denervation-induced skeletal muscle fiber atrophy evidently, resulted in gastrocnemius in injury side an obvious increase in contract function, prevented the loss of weights and protein in denervated skeletal muscle, and ameliorated abnormalities in sciatic nerve cut limbs remarkably. (2) The myotrophic effect of 0.2 mg/kg CNTF is more effective than 0.05 mg/kg. (3) The sensitivity to CNTF varied in muscles of different type; slow twitch muscle (soleus muscle) reacted to CNTF stronger and quicker than twitch muscle (extensor digitorum longus).

CNTF significantly attenuates denervation-reduced skeletal muscle atrophy and dysfunction in SD rats, act an evident myotrophic effect on denervated skeletal muscle. And this effect may be exerted in a dosage dependent manner and varies with muscle type.