High expression of MHC I in the tibialis anterior muscle of a paraplegic patient

A long-term paraplegic man presented exclusively (>99%) myosin heavy chain I (MHC I) in the tibialis anterior muscle (TA). This was coupled to a slow speed of contraction, a high resistance to fatigue, and a rapid resynthesis of phosphocreatine after an electrically evoked fatiguing contraction when compared with the TA muscles of 9 other paraplegic individuals. In contras t, the MHC composition of his vastus lateralis, gastrocnemius, and soleus m uscles was that expected of a muscle from a spinal cord injured individual. This information may be of clinical importance in terms of the expected mo rphological and functional adaptations of skeletal muscle to different type s of electrical stimulation therapy. (C) 1999 John Wiley & Sons, Inc.