Comparison of the Metabolic Effects of All-in-one and Conventional Total Parenteral Nutrition Infusions in Rats

Abstract

All-in-one TPN solution has been widely used, and proven as a stable and safe admixture in the United States and Europe. In Taiwan, we use a conventional method, which is to infuse amino acid-dextrose mixture and lipid emulsion separately. The aim of this study was to compare the metabolic effects of all-in-one TPN infusion with that of the conventional method. Male Wistar rats (~275g) underwent catheter placement (day 0) were infused with equal volumes of isocaloric and isonitrogenous TPN solutions (day 0 to 7). There were 3 TPN groups, i.e., to infuse all- in-one TPN solution 24 hours (24A), or amino acid-dextrose mixture 24 hours with lipid emulsion 24 (24L) or 4 hours (4L) during a day. All the TPN groups received similar amount of lipid emulsion in a day. An orally-fed group with catheter placement was included (Sham). The stability of all-in-one TPN solution was observed visually. There were no significant differences in body weight gain (day 0-7), feed efficiency, and the average of nitrogen retention among TPN and Sham groups (P＜0.05). Serum levels of total protein and albumin, and the percentage of carcass protein were significantly higher, whereas the level of white blood cell was significantly lower in 24A than 24L. Serum concentrations of cholesterol and triglyceride, and hepatic contents of phospholipid (mg/g liver) were significantly higher in 24A than 4L, whereas hepatic content of triglyceride was significantly higher in 4L than 24A. Our results showed that all-in-one TPN infusion may be more likely to induce anabolic response than that of 24 hour lipid-separated infusion, and the conventional method with infusing daily amount of lipid emulsion during 4 hours tended to accumulate lipid in the liver. Based on the simplified preparation, lower cost, and less nursing care, all-in-one TPN solution has the potential to be applied in Taiwan.