Fractionation of abdominal muscle in tumor-bearing, starved, and cortisone-treated rats.

Abdominal muscle of rats bearing Walker carcinosarcoma 256 was fractionated into 11 protein subfractions. The results were quantitatively compared with normal, starved, and cortisonetreated animals. Carcass nitrogen was determined as well. Although approximately equal losses of carcass protein were observed in severely starved animals, in animals which re sponded most severely to cortisone administration, and in animals bearing the largest tumors, the patterns of loss of individual protein fractions from abdominal muscle were dis tinctly different with each treatment.