The effects of short-term parenteral nutrition on human liver protein and amino acid metabolism during laparoscopic surgery.
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.
Barle
H
H
Department of Anesthesiology and Intensive Care, Huddinge University Hospital, Karolinska Institute, Stockholm.
Nyberg
B
B
Andersson
K
K
Essén
P
P
McNurlan
M A
MA
Wernerman
J
J
Garlick
P J
PJ
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
D000596:Amino Acids; D011506:Proteins; D010649:Phenylalanine