Liver albumin synthesis in sepsis in the rat: influence of parenteral nutrition, glutamine and growth hormone

2003 ◽  
Vol 105 (6) ◽  
pp. 691-698 ◽  
Author(s):  
Michael J. O'LEARY ◽  
Michael KOLL ◽  
Colin N. FERGUSON ◽  
John H. COAKLEY ◽  
Charles J. HINDS ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Protein Synthesis ◽  
Parenteral Nutrition ◽  
Acute Phase Proteins ◽  
Statistical Significance ◽  
Synthesis Rate ◽  
Albumin Synthesis ◽  
Fractional Rate ◽  
Caecal Ligation And Puncture ◽  
Hepatic Protein Synthesis

The effect of sepsis on liver synthesis of albumin remains controversial, with studies in man suggesting that synthesis increases, whereas in animals increased, decreased and unaltered synthesis have been reported. To reconcile these conflicting data, total and relative albumin synthesis was measured in rats 24 h after caecal ligation and puncture (CLP) by immunoprecipitation of albumin following a flooding dose of L-[4-3H]phenylalanine. Following CLP, animals were starved for 18 h and then received intravenous infusions of saline or parenteral nutrition (PN) with or without glutamine for 6 h. In animals receiving PN, parenteral injections of growth hormone (GH) or saline vehicle were also administered. Fractional rate of liver total protein synthesis was elevated and total albumin synthesis rate was reduced in all CLP groups when compared with non-operated animals. Total albumin synthesis was also lower in all animals receiving PN than those receiving saline alone, although these differences did not attain statistical significance, except for the group receiving PN+GH. Relative albumin synthesis was also reduced after CLP, and was significantly lower in animals receiving PN than in those receiving saline alone. These findings suggest that in sepsis hepatic protein synthesis is reprioritized away from the production of albumin towards the production of acute-phase proteins and that this change is not influenced by the provision of nutritional support, glutamine or the administration of GH.

scholarly journals The effect of protein depletion and repletion on muscle-protein turnover in the chick

1981 ◽  
Vol 194 (3) ◽  
pp. 811-819 ◽  
Author(s):  
M L MacDonald ◽  
R W Swick
Keyword(s):  
Protein Synthesis ◽  
Protein Turnover ◽  
Muscle Protein ◽  
Control Diet ◽  
Breast Muscle ◽  
Synthesis Rate ◽  
Protein Depletion ◽  
Protein Mass ◽  
Fractional Rate

Rates of growth and protein turnover in the breast muscle of young chicks were measured in order to assess the roles of protein synthesis and degradation in the regulation of muscle mass. Rates of protein synthesis were measured in vivo by injecting a massive dose of L-[1-14C]valine, and rates of protein degradation were estimated as the difference between the synthesis rate and the growth rate of muscle protein. In chicks fed on a control diet for up to 7 weeks of age, the fractional rate of synthesis decreased from 1 to 2 weeks of age and then changed insignificantly from 2 to 7 weeks of age, whereas DNA activity was constant for 1 to 7 weeks. When 4-week-old chicks were fed on a protein-free diet for 17 days, the total amount of breast-muscle protein synthesized and degraded per day and the amount of protein synthesized per unit of DNA decreased. Protein was lost owing to a greater decrease in the rate of protein synthesis, as a result of the loss of RNA and a lowered RNA activity. When depleted chicks were re-fed the control diet, rapid growth was achieved by a doubling of the fractional synthesis rate by 2 days. Initially, this was a result of increased RNA activity; by 5 days, the RNA/DNA ratio also increased. There was no evidence of a decrease in the fractional degradation rate during re-feeding. These results indicate that dietary-protein depletion and repletion cause changes in breast-muscle protein mass primarily through changes in the rate of protein synthesis.

Regulation of hepatic protein synthesis in chronic inflammation and sepsis

1992 ◽  
Vol 262 (2) ◽  
pp. C445-C452 ◽  
Author(s):  
T. C. Vary ◽  
S. R. Kimball
Keyword(s):  
Protein Synthesis ◽  
Sterile Inflammation ◽  
Chain Elongation ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Translational Efficiency ◽  
Liver Protein ◽  
Ribosomal Subunits ◽  
Hepatic Protein Synthesis

The regulation of protein synthesis was determined in livers from control, sterile inflammatory, and septic animals. Total liver protein was increased in both sterile inflammation and sepsis. The rate of protein synthesis in vivo was measured by the incorporation of [3H]phenylalanine into liver proteins in a chronic (5 day) intra-abdominal abscess model. Both sterile inflammation and sepsis increased total hepatic protein synthesis approximately twofold. Perfused liver studies demonstrated that the increased protein synthesis rate in vivo resulted from a stimulation in the synthesis of both secreted and nonsecreted proteins. The total hepatic RNA content was increased 40% only in sterile inflammation, whereas the translational efficiency was increased twofold only in sepsis. The increase in translational efficiency was accompanied by decreases in the amount of free 40S and 60S ribosomal subunits in sepsis. Rates of peptide-chain elongation in vivo were increased 40% in both sterile inflammation and sepsis. These results demonstrate that sepsis induces changes in the regulation of hepatic protein synthesis that are independent of the general inflammatory response. In sterile inflammation, the increase in protein synthesis occurs by a combination of increased capacity and translational efficiency, while in sepsis, the mechanism responsible for accelerated protein synthesis is an increased translational efficiency.

Responses of Tissue Protein Synthesis to Nutrient Intake in Rats Exposed to Interleukin-1β Or Turpentine

1993 ◽  
Vol 85 (3) ◽  
pp. 337-342 ◽  
Author(s):  
Peter E. Ballmer ◽  
Margaret A. McNurlan ◽  
Ian Grant ◽  
Peter J. Garlick
Keyword(s):  
Protein Synthesis ◽  
Parenteral Nutrition ◽  
Young Male ◽  
Interleukin 1Β ◽  
Male Rats ◽  
Synthesis Rate ◽  
Phase Reaction ◽  
Inflammatory Conditions ◽  
Tissue Protein Synthesis ◽  
Growing Rat

1. The influence of an acute-phase reaction on the ability of protein synthesis rates in liver and three different muscles (gastrocnemius, soleus and heart) to respond to a short intravenous infusion of nutrients (glucose plus amino acids) was investigated during experimental inflammation induced by injection of human recombinant interleukin-1β or turpentine in young male rats. 2. Interleukin-1β induced a consistent increase of 3°C in body temperature between 3 and 5 h after injection, whereas turpentine induced a delayed fever, peaking by 13 h. 3. Interleukin-1β and turpentine stimulated fractional rates of protein synthesis in liver. The synthesis rate was inhibited by interleukin-1β in gastrocnemius and soleus muscle, but an elevation was seen in heart muscle. In this study there was no significant response of muscle to turpentine injection. 4. Two hours of parenteral nutrition increased fractional synthesis rates in all tissues when compared with Ringer's lactate. Somewhat larger responses to feeding were observed as a result of either interleukin-1β or turpentine injection in all tissues, but these improvements were not significant. 5. We conclude that the response of protein synthesis rates in liver and skeletal muscle to parenteral nutrition is not inhibited, and may be somewhat enhanced, during acute inflammatory conditions in the growing rat.

Hepatic protein synthesis rate of liver specimens as a predictor of viability in rat cold ischemia liver transplantation model

1997 ◽  
Vol 27 (5) ◽  
pp. 894-902 ◽  
Author(s):  
Yoshifumi Matsui ◽  
Takehide Asano ◽  
Toshio Nakagohri ◽  
Yoshiharu Yokoro ◽  
Osamu Kainuma ◽  
...  
Keyword(s):  
Liver Transplantation ◽  
Protein Synthesis ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Cold Ischemia ◽  
Hepatic Protein Synthesis ◽  
Transplantation Model

scholarly journals Growth Hormone Stimulates Protein Synthesis during Hypocaloric Parenteral Nutrition

1988 ◽  
Vol 208 (2) ◽  
pp. 136-142 ◽  
Author(s):  
JAMES MCK. MANSON ◽  
ROBERT J. SMITH ◽  
DOUGLAS W. WILMORE
Keyword(s):  
Growth Hormone ◽  
Protein Synthesis ◽  
Parenteral Nutrition

Protein metabolism in skin and muscle of sheep selected for or against staple strength

2000 ◽  
Vol 51 (5) ◽  
pp. 541 ◽  
Author(s):  
N. R. Adams ◽  
S. M. Liu ◽  
J. R. Briegel ◽  
J. C. Greeff
Keyword(s):  
Growth Rate ◽  
Protein Synthesis ◽  
Synthesis Rate ◽  
Deuterated Water ◽  
Feeding Level ◽  
Fractional Rate ◽  
Wool Growth ◽  
Fractional Synthesis ◽  
Selection For ◽  
Staple Strength

Two experiments were carried out to determine the mechanisms underlying the reduced effect of nutritional status on wool growth rate in Merino sheep that have been selected for high staple strength (SS). In Expt 1, each group of 6 young sheep of SS+ and SS– genotypes were fed at 0.4 or 1.1 times maintenance, and in Expt 2, groups of 8 sheep of each genotype were fed at 1.1 and 1.8 times maintenance. In both experiments, rates of protein synthesis in skin, muscle, gut, rumen, and liver were determined using a flooding dose of labelled phenylalanine. Feed intake and the digestibility of feed were not affected by genotype. Neither dissection of the carcasses at slaughter, nor deuterated water analysis in Expt 1, detected any differences between the genotypes in body composition. The feeding level affected the total daily amount of protein synthesised in all the organs examined, and the fractional rate of protein synthesis was affected by feeding level in all organs except the liver. The fractional synthesis rate of protein was less responsive to feeding level in the SS+ sheep in both skin and muscle (P < 0.05), but not in the liver, jejunum, or rumen. Total protein synthesis in muscle, and the estimated rate of protein degradation, were also less responsive to feeding level in the SS+ sheep (P < 0.05). We conclude that sheep genetically selected for high or low SS have altered local mechanisms in both skin and muscle that control the way they respond to nutrition. These findings provide a mechanism by which selection for wool growth rate also affects body metabolism.

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