Dietary fat level as determinant of protein-sparing actions of structured triglycerides.
This study assessed the effects of total parenteral nutrition (TPN) containing long-chain triglycerides (LCTs), an equimolar physical mixture of LCT and medium-chain triglycerides (MCTs), and a structured triglyceride synthesized from equimolar amounts of MCT and LCT on energy and protein metabolism after thermal injury (25% body surface area full-thickness scald burn). Male Sprague-Dawley rats (245-271 g) received isovolemic diets intravenously that supplied 250 kcal.kg-1.day-1, 2 g amino acid nitrogen.kg-1.day-1, and 50% of nonprotein calories as lipid and 50% as dextrose for 3 days. Whole-body and tissue leucine kinetics were estimated by a 4-h continuous infusion of L-[1-14C]leucine on day 3. Nitrogen balance, plasma albumin, plasma glucose, energy expenditure, and whole-body and liver and rectus muscle protein kinetic parameters were determined. No significant differences were noted in any of the parameters measured. This study suggests that the unique protein-sparing actions usually associated with structured triglyceride administration are not seen when they are provided as 50% of nonprotein calories. In addition, the ratio of MCT to LCT in the starting mixture from which the structured triglycerides are synthesized may be an important determinant of the protein-sparing actions attributed to these lipids.
Gollaher
C J
CJ
Laboratory of Nutrition/Infection, New England Deaconess Hospital, Harvard Medical School, Boston, Massachusetts 02215.
Swenson
E S
ES
Mascioli
E A
EA
Babayan
V K
VK
Blackburn
G L
GL
Bistrian
B R
BR
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002149:Energy Intake; D004734:Energy Metabolism / Q000187:drug effects; D005217:Fat Emulsions, Intravenous / Q000008:administration & dosage*; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008297:Male; D009132:Muscles / Q000378:metabolism; D009584:Nitrogen / Q000008:administration & dosage / Q000378:metabolism; D010289:Parenteral Nutrition, Total; D011506:Proteins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012709:Serum Albumin / Q000378:metabolism; D014280:Triglycerides / Q000008:administration & dosage* / Q000494:pharmacology
D001786:Blood Glucose; D005217:Fat Emulsions, Intravenous; D011506:Proteins; D012709:Serum Albumin; D014280:Triglycerides; D009584:Nitrogen