Acute stimulation of albumin synthesis rate with oral meal feeding in healthy subjects measured with [ring-2H5]phenylalanine.
1. The short-term effect of oral feeding on albumin synthesis rate was investigated in 12 healthy volunteers using two meal regimens. Albumin synthesis was measured over 90 min after injection of a 'flooding' amount (43 mg/kg body weight) of phenylalanine enriched to 7.5, 10 or 15 atoms % with the stable isotope [ring-2H5]phenylalanine. 2. In one set of subjects, consumption of five small hourly meals resulted in a consistent and significant increase (P < 0.05) in albumin fractional synthesis rate from a mean (+/- SEM) fasting value of 5.8 (+/- 0.4)%/day to 7.1 (+/- 0.4)%/day in the fed state. 3. A second study in which albumin synthesis was measured 30 min after consumption of a single larger meal was carried out in another set of volunteers. The fractional rate of albumin synthesis was again significantly elevated after feeding (P < 0.05), rising from 7.1 (+/- 0.4)%/day in the fasted state to 9.1 (+/- 0.6)%/day in the fed state. In both studies, similar responses were observed in the absolute rate of albumin synthesis (mg day-1 kg-1). 4. Albumin secretion time was significantly shorter (P < 0.05) after feeding in both studies, suggesting that the acute stimulation in albumin synthesis observed after feeding may in part be mediated via a post-transcriptional mechanism. 5. The response of total liver protein synthesis to oral feeding was investigated in an animal model employing adult rats studied with a flooding amount of [2,6-3H]phenylalanine.(ABSTRACT TRUNCATED AT 250 WORDS)
Hunter
K A
KA
Rowett Research Institute, Aberdeen, U.K.
Ballmer
P E
PE
Anderson
S E
SE
Broom
J
J
Garlick
P J
PJ
McNurlan
M A
MA
D000328:Adult; D000818:Animals; D004435:Eating / Q000502:physiology*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008297:Male; D010649:Phenylalanine / Q000008:administration & dosage* / Q000097:blood; D014176:Protein Biosynthesis; D051381:Rats; D017208:Rats, Wistar; D012709:Serum Albumin / Q000378:metabolism*
D012709:Serum Albumin; D010649:Phenylalanine