Host and tumor growth and energy substrates in blood of hepatoma-bearing rats receiving high-fat parenteral infusions.

We examined the effects of isocaloric carbohydrate-based TPN vs fat-based TPN on plasma levels of energy substrates and insulin and on growth of Morris Hepatoma 7777 and host animals. Hepatoma-bearing rats fed similar diets ad libitum served as controls. Although no differences in tumor growth were observed, host weight loss was less in parenterally than in orally fed animals. Liver lipid and plasma free fatty acids and triglycerides in tumor-bearing and normal rats infused high-fat TPN were markedly higher than in all other groups, suggesting that this level of lipid infusion exceeds the rate of utilization. Plasma glucose and insulin in tumor-bearing rats infused high-fat TPN were higher than in all other groups, which may indicate insulin resistance. Replacing glucose energy in TPN with lipid does not appear to reduce glucose availability to tumors but does have potentially deleterious effects on the host.