The concentration of lipids and water in skeletal muscle of albino rats bearing Walker carcinoma 256.

level of water, neutral fat, total cholesterol, free cholesterol, and phospholipid, expressed as gm/100 gm dry weight, in the carcass (host rat minus tumor) of albino rats bearing Walker car cinoma @56shifts toward the level of these dc ments in the tumor (5). These changes, which have been categorized collectively as the hydrolipo tropic shift, appear in the host carcass after @†" 4 weeks of tumor growth (4). In most organs and tissues of the host, hydrolipotropic shifts toward tumor levels are not gross changes demonstrable by single analyses. They can be demonstrated by statistical analysis of differences between a series of twin rats, one inoculated and one not inoculated with Walker carcinoma @56. of thevarious organs andtissues studied to date, the skeletal musculature appears to make a major contribution toward the hydrolipotropic shifts in host carcass (4, 5). A decrease in the con centration of neutral fat and an increase in the concentration of the remaining four elements have been reported in skeletal muscles of albino rats bearing Walker carcinoma @56 (4, 5). This hydro lipotropic shift is identical to that in host carcass. In no other organ or tissue of the host rat have all five such shifts been recorded. Hydrolipotropic shifts have been studied to date in the following organs of albino rats bearing Walker carcinoma @56: brain (9), duodenum (9), heart (9), intestinal tract (3), liver (9), lung (9), skin (9), spleen (8), testicle (4, 5), and thymus gland (6). A decrease in concentration of neutral fat, which includes all fatty acids not estimated to be present in cholesterol esters or phospholipids, has been found in skin, duodenum, and intestinal tract, with no significant alteration in the other organs. An increase in the concentration of total cholesterol was noted in testicle and thymus gland, a decrease in the enlarged spleen, and no change in the other organs. An increase in the level of free cholesterol was reported in testicle, liver, and * This investigation was supported by a grant from the thymus gland, a decrease in spleen, and no change in the other organs. An increase in the concentra tion of phospholipid has been encountered in duo denum, intestinal tract, and thymus gland, with no change in the other organs. An increase in the concentration of water was recorded in heart, lung, duodenum, intestinal tract, liver, thymus gland, and spleen, a decrease in testicle, and …