Effects of exogenous catecholamines on glucose and fat metabolism and on triglycerides in the rat liver during total parenteral nutrition.

An experiment was undertaken to investigate the effects of a continuous infusion of catecholamines on glucose and fat metabolism as well as on nitrogen balance and the amount of triglycerides in the rat liver. The animals were nourished by total parenteral nutrition for 5 days and divided into six groups (n = 5 in each group) on the basis of nonprotein calories given with or without an infusion of catecholamines: group G received 100% of nonprotein calories with glucose, group F received 50% of nonprotein calories with glucose, and the remaining 50% with lipid emulsion, groups Epi-G and Epi-F received epinephrine (1 microgram/kg body weight/min) in addition to the same total parenteral nutrition solution as group G or F, and groups Nor-G and Nor-F received norepinephrine (1 microgram/kg/min) in a similar manner. Each group was administered the same number of total calories (252 cal/kg/day) and the same amount of nitrogen (1.49 g/kg/day). Nitrogen balance was better in group G than in group F. Under catecholamine infusion, there were no significant differences in nitrogen balance between groups Epi-G, Nor-G, Epi-F, and Nor-F, but this parameter improved significantly in group Nor-F in comparison to group F. Liver triglycerides was higher in groups Epi-G and Nor-G than in groups Epi-F and Nor-F. Liver triglycerides was directly related to the blood sugar level. These results indicate that nitrogen conservation is improved with lipid emulsion and that glucose rather than lipid plays a significant role in the genesis of fatty liver, when they are administered under catecholamine-induced stress.