phosphocreatine and Bacterial-Infections

In this study we compared the effect of sepsis on muscle protein metabolism in infant (3 to 4 weeks) and adult (3 to 4 months) rats. Sepsis was induced by cecal ligation and puncture (CLP). Control animals underwent sham operation. Sixteen hours after CLP or sham operation, metabolic studies were performed in incubated intact extensor digitorum longus muscles from infant rats or in strips of the same muscle from adult rats. Protein synthesis rate was determined as incorporation of 3H-phenylalanine into protein; total and myofibrillar protein breakdown rates were determined as release of tyrosine and 3-methylhistidine, respectively. Mortality rate following CLP was similar in both age groups. Basal protein synthesis rate was 3 times higher, total protein breakdown rate was 50% higher, and myofibrillar protein breakdown rate was 3 times higher in infant than in adult animals. However, the relative changes in protein turnover rates induced by sepsis were similar in infant and adult rats: protein synthesis rate decreased by approximately 30%, total protein breakdown increased by 40% to 50%, and myofibrillar protein breakdown increased severalfold. The data suggest that despite prominent differences in basal protein turnover rates between infant and adult rats, the effect of sepsis on muscle protein metabolism is not age dependent.

Topics: Adenosine Triphosphate; Age Factors; Animals; Bacterial Infections; Cecum; Disease Models, Animal; Ligation; Male; Methylhistidines; Muscle Proteins; Muscles; Phosphocreatine; Rats; Rats, Sprague-Dawley; Tyrosine

1. Intramuscular concentrations of adenosine 5'-triphosphate (ATP) and creatine phosphate were measured in the vastus lateralis muscle of 28 non-septic malnourished patients and 31 septic malnourished patients. Similar measurements were made on the rectus abdominis muscle of about one-third of these patients. All results were compared with those obtained from 15 normally nourished non-septic control subjects. 2. Objective measurements of nutritional status (both anthropometric and biochemical) and sepsis were recorded in all subjects. 3. The vastus lateralis muscle of the non-septic and septic malnourished patients had intramuscular concentrations of ATP and total adenine nucleotides (TAN) that were up to 30% lower than control values, depending on the reference base used. 4. In the rectus abdominis muscle, ATP and TAN concentrations were up to 60% lower than control values, and creatine phosphate up to 47% lower, again depending on the reference base used. 5. In both muscles, the changes were more marked in those patients who were septic as well as malnourished.

Topics: Adenosine Triphosphate; Adult; Aged; Aged, 80 and over; Bacterial Infections; Humans; Middle Aged; Muscles; Nutrition Disorders; Phosphocreatine

Experiments were conducted to test the hypothesis that the previously demonstrated depression in ventricular function of rats with hyperdynamic sepsis was a result of depressed high energy phosphate levels or altered myocardial substrate utilization. Rats were inoculated with a pooled fecal homogenate, and 48 hr later their hearts were removed and studied using the Langendorff preparation. The coronaries were perfused with a hydrostatic pressure of 90 mmHg, and hearts were paced at 310-320 beats/min. Substrate oxidation was determined by supplying 14C-labeled glucose, lactate, or palmitate in physiologic concentrations, ie, 5.5, 1, and 0.6 mM, respectively. Hearts were frozen either in situ or after 40-50 min of perfusion for the determination of tissue metabolite levels. Myocardial content of high energy phosphates, total adenine nucleotides, and creatine were similar in septic animals and time-matched controls both in situ and after perfusion. Oxidation of exogenous substrates accounted for the total myocardial O2 consumption in both groups of perfused hearts. Palmitate oxidation was responsible for approximately 50% of the total O2 consumption of the heart, with glucose accounting for approximately 20% and lactate for the remainder. The percentage contribution of the three substrates to oxidative metabolism was similar in hearts from septic and time-matched controls; therefore, myocardial substrate preference was not altered by sustained sepsis. These studies also indicate that ischemia and the concomitant fall in high energy phosphates do not contribute to the myocardial dysfunction of hyperdynamic sepsis.

Topics: Adenine Nucleotides; Animals; Bacterial Infections; Energy Metabolism; Glucose; Glycogen; Lactates; Lactic Acid; Myocardium; Palmitic Acids; Phosphocreatine; Rats; Triglycerides