Influence of starvation, surgery, and sepsis on cardiac protein synthesis in rats: effects of parenteral nutrition, glutamine, and growth hormone.
The effect of sepsis on the rate of protein synthesis in the heart is poorly described. We have investigated changes in protein synthesis in the ventricles of the heart over time after cecal ligation and puncture (CLP) in rats in comparison with sham-operated and unoperated animals (ad libitum). All operated animals were starved from the time of surgery to the time of sacrifice. When operated animals were compared with ad libitum animals, ventricular weight and ventricular protein, and DNA and RNA contents were unchanged at 24 h, but were invariably reduced at 72 and 96 h. Fractional rate of protein synthesis (FSR), RNA activity, and cellular efficiency were reduced at 24 h and further reduced at 72 and 96 h. There were no differences, however, between septic and sham-operated animals. Eighteen hours after CLP, additional groups of rats were infused intravenously with 0.9% sodium chloride, parenteral nutrition (PN), or PN with glutamine, and were given a single dose of 400 microg recombinant human growth hormone (rhGH) or an equal volume of 0.9% sodium chloride. FSR was higher in animals given PN when compared with those given 0.9% sodium chloride only, and did not differ from FSR measured in unoperated animals. There was no additional benefit from the acute administration of either glutamine-enriched PN or rhGH. These results indicate that ventricular protein synthesis is markedly reduced by surgery and starvation, but that superimposed sepsis does not further influence these changes. PN can prevent the fall in cardiac protein synthesis associated with starvation, surgery, and sepsis, but neither glutamine nor rhGH produced any additional benefit.
D000818:Animals; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D004247:DNA / Q000032:analysis / Q000378:metabolism; D005973:Glutamine / Q000494:pharmacology*; D013006:Growth Hormone / Q000494:pharmacology*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010288:Parenteral Nutrition; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics; D012313:RNA / Q000032:analysis / Q000378:metabolism; D051381:Rats; D018805:Sepsis / Q000378:metabolism*; D013217:Starvation / Q000378:metabolism*
D011506:Proteins; D005973:Glutamine; D012313:RNA; D013006:Growth Hormone; D004247:DNA