CORRELATION OF LYSOSOMAL ENZYMES AND CACHEXIA IN THE TUMOR-BEARING RAT

An implantable mammary adenocarcinoma DMBA 1 was described in the female Fischer 344 rat which appeared to be quite stable, growing locally and subcutaneously with no metastasis and with readily definable effects on the host. The effects of tumor cachexia were easily studied in this model and were compared to the effects of starvation. Animals bearing tumors gained slightly in weight over controls at first, but then the carcass of the tumor-bearing animal began to lose weight while the tumor continued to accelerate in growth. By day 20, food and water consumption in the tumor group started declining more than in the control group. Liver weight was significantly elevated in the tumor group and decreased in the starvation group compared to controls. The dry weight to wet weight ratio was decreased in both groups compared to controls. The calculated total dry weight increased in the tumor group and decreased markedly in the starvation group. White blood cell counts were markedly elevated in the tumor group with a high percentage of polymorphonuclear leukocytes. Plasma lysosomal enzyme activity was relatively low for all 3 groups. There were significant elevations of lysosomal enzymes in the tumor group in liver and muscle compared to controls. Most of this increased activity appeared to be in the free or nonlysosomally bound fraction of the homogenized tissue. These tissue lysosomal enzyme changes may be contributing to tissue alterations seen in the tumor cachectic host.