The effect of
total parenteral nutrition with combinations of long-chain
triglycerides (LCTs) and
triacetin, the water-soluble
triglyceride of
acetate, on structural components of the gastrointestinal tract and
protein metabolism was assessed in burned (30% body surface area) rats. Rats received isovolemic, isocaloric, and isonitrogenous diets that delivered 672 kJ.kg-1.d-1 (160 kcal.kg-1.d-1), 9.6 g amino acids.kg-1.d-1, and 30% nonprotein calories as 90%
triacetin/10% LCTs, 50%
triacetin/50% LCTs, or 100% LCTs for 7 d. Daily and cumulative
nitrogen balances and whole-body
leucine kinetics and fractional
protein synthetic rates in rectus muscle and liver were determined on the last day of nutrition.
DNA,
protein, and total weight were determined in mucosal scrapings from segments of jejunum and colon. Plasma
acetate concentrations were substantially higher in both
triacetin groups.
Parenteral nutrition with 50%
triacetin and 50% LCTs promoted a positive
nitrogen balance similar to that of 100% LCTs, increased
protein in rectus muscle and liver, smaller and more numerous mucosal cells in jejunum and colon, and increased colonic mucosal weight compared with the other groups.
Triacetin did not appreciably affect whole-body and tissue
leucine kinetics. The equicaloric provision of
triacetin and LCTs improved
protein utilization and structural components of the small and large bowel and reduced the development of intestinal mucosal
atrophy associated with conventional
parenteral nutrition in
burn injury.