Total parenteral nutrition with and without fat as substrate for growth of rats and transplanted hepatocarcinoma.
Differential effects of total parenteral nutrition (TPN) on host nutrition and growth of cancer are unclear. Growth of adult ACI-N rats bearing transplanted Morris hepatocarcinoma no. 3924A given TPN with or without fat was studied in comparison with Purina Chow-fed, fasting, and semifasting (either amino acid or dextrose alone) rats over 5 days. The isocaloric, isonitrogenous TPN regimens with or without fat maintained body weight and nitrogen balance of cancer-bearing rats equally well. When compared with Chow-fed rats, the volume of the cancer, its weight, doubling time, protein content, and incorporation of thymidine into DNA were similar in rats given TPN either with or without fat. Although the volume of the cancer decreased in fasting and semifasting rats, the nutritional status of the host was also impaired. Administration of TPN to cancer-bearing rats was associated with an abnormal increase in serum lactic acid level, which was not ameliorated by the use of fat to reduce the carbohydrate load. Although TPN with and without fat maintains the nutritional status, hepatomegaly and hepatic steatosis limit the administration of carbohydrate and fat as energy substrates in this system.