STUDIES ON THE LIPID-METABOLISM OF WALKER-256 TUMOR-BEARING RATS DURING THE DEVELOPMENT OF CANCER CACHEXIA

Aspects of the lipid metabolism of Walker 256 carcinosarcoma-bearing c achectic rats (TB) were investigated during a 14 day interval of tumou r growth. Food intake and body weight of the TB rats were reduced by 1 8 % and 13 %, respectively, on day 14, as compared with non-tumour-bea ring animals. The tumour burden then, corresponded to 19 % of total bo dy weight. The total fat content was not different in the liver, heart , carcass, epididymal (EAT) and retroperitoneal (RPAT) adipose tissues of the two groups. The brown adipose tissue (BAT) and skeletal muscle (gastrocnemius-SM) of the TB rats had increased levels of fat (23 % a nd 200 %, respectively). Enteral absorption of C-14-triolein was decre ased in the TB rats, but the liver, heart, and SM of these animals inc orporated more radiolabelled lipid than the control animals, while the adipose tissues exhibited a decreased incorporation of radioactivity in relation to controls. More lipid was incorporated into the VLDL fra ction secreted by the liver of TB rats, which exhibited a different di stribution of the incorporated C-14-oleate in the various lipid subfra ctions. Ultrastructural studies showed that the hepatocytes of the TB rats had a greater incidence of lipid droplets in the cytoplasm.