Protein composition of denervated muscle

¹ Department of Zoology, Montana State University, Missoula, Montana

The protein composition of normal and denervated rat gastrocnemius muscles was determined. In addition, denervated muscles subjected to rhythmical stretching and electrically stimulated denervated muscles were analyzed. In the normal right gastrocnemius 5.33% of the total protein is connective tissue, 29.65% is sarcoplasmic protein, and 65.02% is contractile protein. Fifteen days after denervation, untreated muscles had lost 55.8% of the initial weight and distribution of the protein fractions was different from normal. Connective tissue and sarcoplasmic protein represented larger percentages of the total and contractile protein less of the total protein than in the normal muscle. Rhythmical stretching had no effect on the change in percentage composition which occurred after denervation, but atrophy was significantly retarded. Electrical stimulation was more effective than stretching. By 15 days, the stimulated muscles had lost only 28.3% of the initial weight and protein distribution was more nearly normal than in the stretched muscles.