TROPHIC EFFECT OF CILIARY NEUROTROPHIC FACTOR ON DENERVATED SKELETAL-MUSCLE

The actions and receptor for ciliary neurotrophic factor (CNTF) are la rgely restricted to cells of the nervous system, although one of the C NTF receptor components, CNTFR alpha, is expressed by skeletal muscle. Here we show that the other CNTF receptor components, LIFR beta and g p130, are also expressed by skeletal muscle and that expression of all three CNTF receptor components is greatly increased in denervated mus cle. In vivo, administration of CNTF activates these receptors on skel etal muscle by inducing receptor phosphorylation and immediate-early g ene responses. Furthermore, CNTF reduces the denervation-induced atrop hy of muscle and attenuates the reduced twitch and tetanic tensions th at result from muscle denervation. Our findings reveal that, in additi on to its known neurotrophic actions, CNTF exerts myotrophic effects b y attenuating the morphological and functional changes associated with denervation of rat skeletal muscle.