title: The effects of short-term parenteral nutrition on human liver protein and amino acid metabolism during laparoscopic surgery.
abstract: BACKGROUND
  This study was undertaken to elucidate the specific effects of short-term artificial nutrition on human liver protein metabolism.
  
  
  METHODS
  Thirty patients undergoing elective laparoscopic cholecystectomy were studied: a control group (n = 16) and a group that received total parenteral nutrition (TPN; n = 14). The nutrition consisted of a balanced i.v. solution of nutrients (17.5 nonprotein kcal/kg body wt, 50% fat, 50% carbohydrates, and 0.1 gN/kg) that was discontinued when the investigation was finished, after a total infusion time of 8.6 +/- 1.0 hours. A liver biopsy specimen was taken as soon as possible after surgery was started, for the determination of the free hepatic amino acid concentrations. In 16 of the patients, L[2H5]phenylalanine was given by i.v. to determine the fractional synthesis rate of total liver protein in a second liver biopsy specimen taken approximately 30 minutes later.
  
  
  RESULTS
  The fractional synthesis rate of total liver protein was 15.2% +/- 4.7%/d in the TPN group (n = 7), which was not different from that of the control group (17.7% +/- 3.8%/d, n = 9). However, the free hepatic concentrations of alanine (p < .05) and the essential amino acids increased (p < .001) in the TPN group, whereas the total hepatic amino acid concentrations were comparable between the groups.
  
  
  CONCLUSIONS
  Thus short-term TPN induced specific changes of the free hepatic amino acid concentrations, whereas total liver protein synthesis remained unaffected by the nutrition.
authors.affiliation: Department of Anesthesiology and Intensive Care, Huddinge University Hospital, Karolinska Institute, Stockholm.
authors.forename: H
authors.initials: H
authors.lastname: Barle
authors.forename: B
authors.initials: B
authors.lastname: Nyberg
authors.forename: K
authors.initials: K
authors.lastname: Andersson
authors.forename: P
authors.initials: P
authors.lastname: Essén
authors.forename: M A
authors.initials: MA
authors.lastname: McNurlan
authors.forename: J
authors.initials: J
authors.lastname: Wernerman
authors.forename: P J
authors.initials: PJ
authors.lastname: Garlick
mesh_terms: D000328:Adult; D000368:Aged; D000596:Amino Acids / Q000097:blood / Q000378:metabolism*; D001706:Biopsy / Q000379:methods; D017081:Cholecystectomy, Laparoscopic; D002769:Cholelithiasis / Q000097:blood / Q000601:surgery; D005260:Female; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010289:Parenteral Nutrition, Total; D010649:Phenylalanine / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000596:Amino Acids; D011506:Proteins; D010649:Phenylalanine