title: Influence of trauma on plasma elimination of exogenous fat and on lipoprotein lipase activity and mass.
abstract: BACKGROUND
  Trauma is followed by an increased plasma clearance and oxidation of exogenous fat but the underlying mechanism is not fully understood.
  
  
  OBJECTIVE
  To examine the influence of a surgical trauma on the plasma elimination of exogenous triglycerides (TG) and its relationship with lipoprotein lipase (LPL) activity and LPL mass.
  
  
  METHODS
  Nine patients underwent a hypertriglyceridaemic clamp and a lipolytic capacity test before and after open abdominal surgery. The infusion rate was adjusted to maintain a stable TG concentration of 4 mmol x l(-1) during 180 min. The lipolytic capacity was determined as the change in LPL activity and mass following a bolus dose of 100 IU x kg BW(-1) heparin sodium.
  
  
  RESULTS
  Postoperatively, the plasma elimination rate of fat was 2.6 times higher (P<0.001). Infusion of lipids in the postoperative state was followed by a smaller rise in free fatty acids (P<0.05) in comparison with the preoperative situation. The postoperative basal fasting LPL activity was half of that in the preoperative state and the LPL activity rose almost two-fold during the clamp. The heparin-induced rises in LPL activity and LPL mass were similar (n.s.) before and after surgery.
  
  
  CONCLUSIONS
  A moderate surgical trauma is accompanied by a greater than two-fold rise in plasma elimination rate of exogenous fat despite a lower basal LPL activity and a virtually unchanged LPL pattern during infusion of lipids. Our study demonstrates that although trauma may substantially enhance the fat elimination capacity a significant proportion of the infused fat is not utilized for metabolic purposes.
authors.affiliation: Department of Surgery and Center for Surgical Science (CFSS), Karolinska Institute, Karolinska University Hospital--Huddinge, SE-141 86 Stockholm, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Thörne
authors.forename: W
authors.initials: W
authors.lastname: Aberg
authors.forename: C
authors.initials: C
authors.lastname: Carneheim
authors.forename: T
authors.initials: T
authors.lastname: Olivecrona
authors.forename: J
authors.initials: J
authors.lastname: Nordenström
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D005260:Female; D006801:Humans; D007263:Infusions, Parenteral; D008071:Lipoprotein Lipase / Q000097:blood / Q000378:metabolism*; D008099:Liver / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D014280:Triglycerides / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*
chemical_list: D014280:Triglycerides; D008071:Lipoprotein Lipase