Impairment of albumin and whole body postprandial protein synthesis in compensated liver cirrhosis

Abstract

To investigate the anabolic effects of feeding in cirrhosis, we measured albumin fractional synthesis rate (FSR) and whole body protein synthesis in six nondiabetic patients with stable liver cirrhosis (three in the Child-Pugh classification Class A, three in Class B) and in seven normal control subjects, before and after administration of a 4-h mixed meal. Leucine tracer precursor-product relationships and whole body kinetics were employed at steady state. Basal levels of postabsorptive albumin concentration and FSR, whole body leucine rate of appearance, oxidation, and nonoxidative leucine disposal (NOLD, approximately equal to protein synthesis) were similar in the two groups. However, after the meal, in the patients neither albumin FSR (from 8.5 +/- 1.5 to 8.8 +/- 1.8 %/day) nor NOLD (from 1.69 +/- 0.22 to 1.55 +/- 0.26 micromol x kg(-1) x min(-1)) changed (P = nonsignificant vs. basal), whereas they increased in control subjects (albumin FSR: from 10.9 +/- 1.5 to 15.9 +/- 1.9 %/day, P < 0.002; NOLD: from 1.80 +/- 0.14 to 2.10 +/- 0.19 micromol x kg(-1) x min(-1), P = 0.032). Thus mixed meal ingestion did not stimulate either albumin FSR or whole body protein synthesis in compensated liver cirrhosis. The mechanism(s) maintaining normoalbuminemia at this disease stage need to be further investigated.

Quantifying rates of protein synthesis in humans by use of2H2O: application to patients with end-stage renal disease

“…The subjects were clinically stable and their serum albumin concentrations did not change. A rate of ϳ4.5%/day is comparable to rates obtained by other methods (2,10,34). However, in those methods, measurements are made over a period of hours under a steady-state condition, e.g., the fasted or fed state.…”

Remethylation and transsulfuration of methionine in cirrhosis: Studies with l-[2H3-methyl-1-13C]methionine

“…The decreased turnover may be either a consequence of a decreased incorporation of MET into proteins, which accounts for approximately 75% of the turnover in healthy subjects, 10 and/or a decreased formation of AdoMET through MET adenosyltransferase. Because protein synthesis is not impaired in the fasting state in cirrhosis 17 and other pathways of disposition of MET are quantitatively unimportant, 18,19 a decreased formation of AdoMET is more likely. Consistent with this interpretation a decreased mRNA expression of MET adenosyltransferase has been shown in patients with cirrhosis.…”

Pemberian Diet Formula Tepung Ikan Gabus (Ophiocephalus striatus) pada Sindrom Nefrotik

“…[19][20] Salah satu pengukuran untuk menilai penggunaan protein diet adalah dengan keseimbangan nitrogen. [15][16] Penelitian untuk mengetahui kinerja protein dari diet dengan menggunakan teknik N labeled protein didapatkan bahwa nitrogen diet lebih berperan pada jalur anabolisme yaitu sintesis protein.…”