Growth and body composition during long-term total parenteral nutrition in the rat.

Detailed metabolic data indicating the adequacy of long-term total parenteral nutrition in the rat are not available. In this study an aseptic catheterization technique and a presumed adequate intravenous diet were used to support the nutrition of growing male Fischer 344 rats for a 21-day period. These animals were compared with sham-operated rats after 21 days of ad libitum access to one of two adequate oral diets. Total parenteral nutrition rats demonstrated weight gains that were similar to those in the rats consuming the oral diets. Body composition and nitrogen storage studies indicated fat and protein accumulation in total parenteral nutrition rats that were similar to those in the orally fed animals, but with a tendency toward increased fat and decreased nitrogen retention. These data indicate that apparently normal growth and development can be achieved with total parenteral nutrition in rats by meticulous attention to detail.