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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The relationship of glucogenesis and other energy-requiring functions of the liver to the proteolysis which is characteristic of trauma and sepsis was studied in conscious pigs following laporotomy and after the induction of intraperitoneal sepsis. By means of appropriately placed thermal dilution catheters, portal and hepatic arterial blood flows, hepatic oxygen consumption, glucogenesis, and uptake of the fuel, substrates were measured. No animal was in shock. Despite significant increases of lactate and aminoacids delivered to the liver, the blood concentrations were maintained in the normal range. The rate of glucogenesis was proportional (r equals 0.71) to the sum of the glucogenic precursors (lactate, pyruvate, glycerol, and alanine) taken up by the liver. Higher rates of glucose production were accompanied by elevated blood insulin values. Hepatic oxygen consumption and the uptake of free fatty acids also were related directly to the glucogenic rate, the correlation coefficients being 0.69 and 0.74, respectively. In the absence of shock, the liver function and hepatic energy production remained normal in post-traumatic and septic states. Under the conditions insulin-resistant muscle in the presence of reduced free fatty acid availability mobilize protein to satisfy local energy requirements. Skeletal muscle can oxidize only branch chain aminoacids; other aminoacids, including alanine, are transported to the liver for glucogenesis or other purposed. This concept accounted for failure of glucose infusion to eliminate post-traumatic and septic proteolysis, since alanine is cleared only from blood by conversion in the liver to glucose. Thus it is concluded that in sepsis the release of glucogenic substrates because of altered metabolism in peripheral tissues determines the rate of hepatic glucogenesis. This relationship constitutes an important metabolic homeostatic mechanism.
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PMID:Liver metabolism and glucogenesis in trauma and sepsis. 114 47

The contribution of alanine to the synthesis of glucose and the oxidation of alanine was evaluated in normal and septic patients using (14C)L-alanine. The data indicate that there is a twofold increase in the conversion of alanine into glucose in sepsis and, further, this increase was observed while the patients were receiving a constant glucose infusion (100 mg/min) prior to and during the single injection of (14C)L-alanine. Failure of glucose to decrease this gluconeogenic response in these septic patients clearly indicates that the controlling mechanism for glucose synthesis is modified following injury and undoubtedly plays a role in the abnormal carbohydrate metabolism observed in injury. The contribution of alanine carbon to oxidation was the same in the control and septic group as measured by the per cent of the (14C)L-alanine dose expired in 3 h. Since the control subjects received glucose continuously during the study with and without amino acids, it is clear that nutritional intake and injury has minimal effect on the oxidation of alanine. This suggests that transamination is not affected by sepsis nor is there an inhibition of pyruvate oxidation following sepsis.
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PMID:Nonsuppressability of gluconeogenesis by glucose in septic patients. 125 Jan 57

The catabolism of glucose and amino acids has been studied in the normal, the fasted, and the fasted septic dog. The fasted septic dog oxidized more glucose and alanine, and had more gluconeogenesis from alanine and the five tritiated amino acids--glutamate, threonine, phenylalanine, leucine, and valine--as compared to the normal and equally fasted dog. Thus the total body protein catabolic state was characterized in biochemical terms. In contrast, following glucose infusion, the fasted septic animal responded much like the fasted animal in terms of decreased animo acid gluconeogenesis and decreased plasma concentrations of amino acids, fats and fat products, but considerably increased the oxidation of alanine. The increased alanine oxidation appeared to be primarily related to increased tissue clearance and increased plasma concentration. There was some suggestive evidence for enhanced oxidation of the tritiated amino acids including leucine and valine during glucose infusion. The protein catabolic state secondary to this sort of sepsis in dogs only on per os fluid support appears to be best characterized as a glucose catabolic state with alanine being oxidized directly. Such states are known to be ones of enhanced metabolic rate secondary to enhanced synthetic processes generally. This is probably related to enhanced sympathetic nervous system release of glucagon with insulin being normally responsive to glucose because of a normal plasma epinephrine.
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PMID:Turnover of amino acids in sepsis and starvation: Effect of glucose infusion. 125 26

1. The hepatic metabolism of glutamine, alanine, ammonia, urea, glutathione and glucose was studied in rats made septic by caecal ligation and puncture and was compared with that in rats that had undergone sham operation (laparotomy). 2. Sepsis resulted in increases in the plasma activities of gamma-glutamyltransferase (P less than 0.001), alanine aminotransferase (P less than 0.001) and aspartate aminotransferase (P less than 0.001), the serum total and direct bilirubin concentrations (P less than 0.001), and the blood lactate (P less than 0.01), glutamine (P less than 0.05), alanine (P less than 0.001) and urea (P less than 0.05) concentrations, but produced decreases in the blood ketone body (P less than 0.001) and glutathione (P less than 0.05) concentrations and in the plasma cholesterol concentration (P less than 0.05). These changes were associated with marked negative nitrogen balance in septic rats. 3. Sepsis increased total hepatic blood flow (by 22.7%) together with hepatic arterial flow (by 25.8%) and portal venous flow (by 18.7%). Sepsis resulted in marked increases in the net rates of hepatic extraction of glutamine (by 164%), alanine (by 138%) and ammonia (by 259%) with concomitant increases in the net rates of hepatic release of glutamate (by 105%), glutathione (by 87.5%), glucose (by 70.1%) and urea (by 100.4%). 4. Sepsis increased the activities of liver carbamoylphosphate synthase (by 16.4%), ornithine transcarbamylase (by 29.8%), argininosuccinate synthase (by 28.1%) and arginase (by 33.8%). 5. Septic rats exhibited marked increases in hepatic protein (by 46.0%), RNA (by 43.4%) and DNA (by 37.7%) contents. These changes were accompanied by marked increases in the activity of thymidine kinase (by 35.9%).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Hepatic glutamine metabolism in the septic rat. 137 98

A steroid binding capacity assay and a radioimmunoassay were both used to measure corticosteroid binding globulin (CBG) in serum samples from 22 patients with sepsis. An approximately 50% discordancy between the two values in one patient suggested the presence of a CBG variant with reduced affinity for cortisol, and this was confirmed by Scatchard analysis. We therefore used the polymerase chain reaction to amplify exons that encode for human CBG from the genomic DNA of this patient. This revealed two mutations within the coding sequences: one of which results in a Leu----His substitution at residue 93 and another which encodes a Ser----Ala substitution at residue 224 of the human CBG polypeptide. To assess the impact of each substitution on the steroid binding affinity of CBG, each mutation was introduced separately into a normal human CBG cDNA, and the normal and mutated cDNAs were expressed in Chinese hamster ovary cells. Scatchard analysis of the CBG produced in culture indicated that the His93 mutation (Kd = 2.24 +/- 1.75 nM) reduced the cortisol binding affinity of CBG (mean +/- SD) significantly (P less than 0.024) when compared to normal CBG (Kd = 0.64 +/- 0.31 nM), while the Ala224 mutation (Kd = 0.63 +/- 0.33 nM) did not influence cortisol binding affinity. We therefore conclude that residue 93 may play an important role in determining the structure of the CBG steroid binding site.
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PMID:A Leu----His substitution at residue 93 in human corticosteroid binding globulin results in reduced affinity for cortisol. 150 7

The metabolism of skeletal muscle glutamine was studied in rats made septic by cecal ligation and puncture technique. Blood glucose was not significantly different in septic rats, but lactate, pyruvate, glutamine, and alanine were markedly increased. Conversely, blood ketone body concentrations were markedly decreased in septic rats. Both plasma insulin and glucagon were markedly elevated in septic rats. Sepsis increased the rates of glutamine production in muscle, but without marked effects on skin and adipose tissue preparations, with muscle production accounting for over 87% of total glutamine produced by the hindlimb. Sepsis produced decreases in the concentrations of skeletal muscle glutamine, glutamate, 2-oxoglutarate, and adenosine monophosphate (AMP). The concentrations of ammonia, pyruvate, and inosine monophosphate (IMP) were increased. Hindlimb blood flow showed no marked change in response to sepsis, but was accompanied by an enhanced net release of glutamine and alanine. The maximal activity of glutamine synthetase was increased only in quadriceps muscles of septic rats, whereas that of glutaminase was decreased in all muscles studied. Tyrosine release from incubated muscle preparation was markedly increased in septic rats; however, its rate of incorporation was markedly decreased. It is concluded that there is an enhanced rate of production of glutamine from skeletal muscle of septic rats. This may be due to changes in efflux and/or increased intracellular formation of glutamine; these suggestions are discussed.
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PMID:Glutamine metabolism in skeletal muscle of septic rats. 167 Nov 65

1. The metabolism of glutamine and alanine in the lung was studied in rats made septic by a caecal ligation and puncture technique. 2. The blood glucose concentration was not significantly different in septic rats, but blood pyruvate, lactate, glutamine and alanine concentrations were markedly increased as compared with sham-operated rats. Conversely, blood ketone body and plasma cholesterol concentrations were significantly decreased in septic rats. Both plasma insulin and plasma glucagon concentrations were markedly elevated in response to sepsis. Sepsis resulted in a negative nitrogen balance. 3. Sepsis increased the rates of production of glutamine (52.5%, P less than 0.001), alanine (38.9%, P less than 0.001) and glutamate (48.6%, P less than 0.001) by lung slices incubated in vitro. 4. Sepsis increased lung blood flow by 27.6% (P less than 0.05). Blood flow and arteriovenous concentration difference measurement across the lung of septic rats showed an increase in the net exchange rates of glutamine (142.5%, P less than 0.001), alanine (129.4%, P less than 0.001), glutamate (100.9%, P less than 0.001) and ammonia (138.0%, P less than 0.001) as compared with sham-operated control rats. 5. Sepsis produced significant decreases in the lung concentrations of glutamine (36.8%), glutamate (20.8%), 2-oxoglutarate (64.8%) and AMP (18.3%). The lung concentrations of alanine (95.9%), ammonia (67.7%) and pyruvate (89.7%) were increased. 6. The maximal activities of glutamine synthetase (20.4%, P less than 0.05), phosphate-dependent glutaminase (18.9%, P less than 0.05) and alanine aminotransferase (25.5%, P less than 0.05) were increased, but there was no marked change in that of glutamate dehydrogenase, in the lungs of septic rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Glutamine and alanine metabolism in lungs of septic rats. 168 36

The clearance rate of endogenous and exogenous circulating lipids during the septic or inflammatory state remains a controversial subject. Thus, we have developed rat models of gram-negative and gram-positive sepsis and of sterile inflammation to study this problem. In addition to the febrile response, these stresses induced some of the following metabolic changes in the blood: decreased total protein, albumin, and ketone body levels and increased lactate, pyruvate, alanine, cholesterol, and triacylglycerol levels. The activities of heart, diaphragm, and adipose tissue lipoprotein lipase and of hepatic lipase decreased to differing extents depending on whether the enzyme substrate was a long-chain or a medium- and long-chain triglyceride-based emulsion. However, the latter emulsion was always hydrolyzed faster than the former. This observation suggests that, during infection/inflammation, the medium- and long-chain triglyceride-based emulsion would be cleared more quickly, would induce less hypertriglyceridemia, and would thus deliver lipid energy more rapidly than a traditional long-chain triglyceride-based emulsion.
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PMID:Decreased lipolytic activity in tissues during infectious and inflammatory stress. 180 2

Total parenteral nutrition (TPN) after trauma and sepsis has two major goals. One is the reduction of enhanced protein catabolism; the second is the avoidance of enhancement of whole-body glucose turnover. Glucose and xylitol differ in their quantitative utilization rate after trauma and sepsis. Maximal glucose utilization is reduced during such states, while the utilization of xylitol is more than doubled. In order to investigate whether these differences are associated with beneficial effects with regard to whole-body glucose turnover rate of gluconeogenesis and protein sparing, we conducted two studies using animal models and two clinical studies. METHODS. For the determination of glucose and protein turnover, radioactive and stable isotope techniques were applied. In an animal model a primed constant infusion of 3-H-6-glucose, 14-C-1-alanine and 13-C-3-alanine and 14-C-U-acetate was used to determine total glucose appearance, gluconeogenesis from 3-C-precursors and alanine flux. In the human studies hepatic glucose production was determined by using a primed constant infusion of 6.6-D-2-glucose and urea synthesis rate was determined by a primed constant infusion of 2-N-15-urea. RESULTS. In the first rat model we were able to show that hypocaloric xylitol compared to glucose significantly reduced whole-body glucose turnover from 1741 +/- 232 mumol/h during glucose infusion to 449 +/- 49 mumol/h during xylitol infusion and gluconeogenesis from C-3 carbons form 382 +/- 24 mumol/h during glucose infusion to 155 +/- 39 mumol/h during xylitol infusion after a burn trauma. In a second septic rat model the exchange of glucose calories by xylitol in a proportion of 1:1 was associated with a significantly ameliorated N-balance from +144 +/- 90 mgN/kg body weight per day during glucose infusion to +699 +/- 80 mgN/kg body weight per day during glucose-xylitol infusion and a reduced 3-methyl-histidine excretion from 7.14 +/- 0.61 mumol/kg body wt. per day during glucose infusion to 4.10 +/- 0.56 mumol/kg per day during glucose-xylitol infusion, respectively. In two studies with surgical intensive care patients we were able to confirm the nitrogen-sparing properties of xylitol infusion, together with amino acids during hypocaloric feeding or during TPN with a glucose/xylitol mixture in a proportion of 1:1. From a basal urea production rate of 9.2 +/- 1.6 mumol/kg min. xylitol led to a significant reduction with 6.4 +/- 1.5 mumol/kg per min. Hepatic glucose production was significantly reduced during xylitol infusion from basal 4.8 +/- 0.6 mg/kg per min to 3.1 +/- 0.7 mg/kg per min, respectively. Equicaloric glucose in a dosage of 3 g/kg per day had no effect. During TPN glucose/xylitol, in a proportion of 1:1 at a total dosage of 0.24 g/kg per h, significantly reduced whole-body glucose turnover, endogenous glucose production and lactate concentrations compared to an isocaloric glucose infusion. DISCUSSION. In animal as well as in human studies hypocaloric xylitol as well as a glucose-xylitol mixture were more efficient in preserving body protein than glucose alone. Whole-body glucose turnover was significantly reduced during hypocaloric xylitol or glucose-xylitol infusion compared to isocaloric glucose infusion. During the acute phase after trauma we therefore recommend a carbohydrate supplementation of 3 g/kg body wt. per day using xylitol. During long-term TPN, a glucose-xylitol mixture in a proportion of 1:1 in a dosage of 3 g/kg body wt. per day each is recommended as energy source, together with amino acids and, if necessary, lipids.
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PMID:[The mechanism of the reduction of protein catabolism following trauma and during sepsis using xylitol]. 190 89

Concentrations of amino acids in the plasma of 13 neonatal foals with septicemia were compared with the concentrations of amino acids in the plasma of 13 age-matched neonatal foals without septicemia. Analysis of the results revealed significantly lower concentrations of arginine, citrulline, isoleucine, proline, threonine, and valine in the plasma of foals with septicemia. The ratio of the plasma concentrations of the branched chain amino acids (isoleucine, leucine, and valine) to the aromatic amino acids (phenylalanine and tyrosine), was also significantly lower in the foals with septicemia. In addition, the concentrations of alanine, glycine, and phenylalanine were significantly higher in the plasma of foals with septicemia. Therefore, neonatal foals with septicemia had significant differences in the concentrations of several amino acids in their plasma, compared with concentrations from healthy foals. These differences were compatible with protein calorie inadequacy and may be related to an alteration in the intake, production, use, or clearance of amino acids from the plasma pool in sepsis.
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PMID:Concentrations of amino acids in the plasma of neonatal foals with septicemia. 190 45


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