Printed in U.S.A. Effect of Calorie Overload on Puppy Livers during Parenteral Nutrition

ABSTRACT. To investigate the possible cause of hepatomeg-aly during TI", chemical analyses were performed on the livers of puppies weighing around 2 kg, supported by TI " for 1 wk, under 3 different calorie levels: Group I (5) under 135 cal/ kg as standard calorie, Group 2 (6) fed ad libitum with dog food, Group 3 (5) received TPN for 7 days a t 135 cal/kg/day, Group 4 (5) TPN at 200 cal/kg/day, and Group 5 (5) at 270 cal/kg/ day. The livers of puppies starved for 24 hrs and orally fed were studied as controls. Results: 1) remarkable hepatomegaly with anemic discoloration and rise in sGOT, sGPT, and Alpase were the constant findings in G-2 and G-3.2). Liver weight in starved, fed G-1, G-2, and G-3 were 66.0 f 7.5g. 82.8 f 18.5g. 108.32 f Intravenous hyperalimentation or total parenteral nu-trition (TPN), as developed by Dudrick et al in 1968,' has been widely applied to save critically ill patients but is known to influence the liver in various aspects. A characteristic finding in the liver during TPN is that the cells appear swollen and clear and contain large amounts of PAS-positive substance, which is glycogen? TPN also can cause fatty infiltration of the liver,& ' the exact mechanism of which has not yet been clarified. It has been suggested that caloric overdose by PN results in hepatomegaly. Elevation of serum GOT, GPT, or alkaline phosphatase (Alpase) is a frequent finding during TPN, the cause or clinical implications of which have not yet been established?. ' In the present study, chemical analyses were per-formed on the livers of the puppies which had been supported by TPN for 7 days under 3 different calorie intakes, with macroscopic and microscopic examinations and studies of serum enzymes, lipids, insulin, and blood glucose also done. The results suggest the possibility of the occurrence of hepatomegaly with the accumulation of enormous amounts of glycogen, water, and fatty infil-tration plus a rise in serum enzymes and triglycerides caused by calorie overload in TPN