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(Journal of Nutrition. 2000;130:2897-2902.)
© 2000 The American Society for Nutritional Sciences


Articles

Bacterial Dissemination and Metabolic Changes in Rats Induced by Endotoxemia following Intestinal E. coli Overgrowth Are Reduced by Ornithine {alpha}-Ketoglutarate Administration1

Laurent Schlegel*,{dagger}, Colette Coudray-Lucas*,{dagger}, Frédéric Barbut**, Jacques Le Boucher*, Alain Jardel{ddagger}, Setareh Zarrabian{dagger}{dagger} and Luc Cynober{dagger},{ddagger}{ddagger}2

* INSERM U402, Faculté de médecine Saint-Antoine, 75012 Paris, France; {dagger} Laboratoire de Biologie de la Nutrition, E.A. 2498, Faculté de Pharmacie, 75270 Paris Cedex 06-France; ** Laboratoire de bactériologie, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 75012 Paris, France; {ddagger} Laboratoire de physiologie humaine, UFR de Pharmacie, 49000 Angers, France; {dagger}{dagger} INSERM U458, Hôpital Robert Debré, Assistance Publique-Hôpitaux de Paris, 75019 Paris, France; and {ddagger}{ddagger} INSERM U341, Hôtel-Dieu, 75181 Paris Cedex 04-France

2To whom correspondence should be addressed.


    ABSTRACT
 TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
The efficacy of ornithine {alpha}-ketoglutarate (OKG) in preventing bacterial translocation and dissemination, metabolic disorders and changes in mucosal enzyme activities was assessed in a model of bacterial translocation in rats. Antibiotic decontamination was performed 4 d before intragastric inoculation with an Escherichia coli strain (1010 bacteria/kg body). Two days later, the rats were given either a lipopolysaccharide (LPS) 0127:B8 or a saline injection and were deprived of food for 24 h. Enteral nutrition, [Osmolite, 880 kJ/(kg · d)] supplemented with either OKG (LPS + OKG) or glycine (Saline + Gly or LPS + Gly), was then given for 2 d. Urinary total nitrogen losses and 3-methylhistidine excretion were determined daily. On killing at d 3, bacterial translocation to the mesenteric lymph nodes (MLN) and dissemination to the spleen and liver were evaluated, jejunal mucosa enzyme activities were assayed and tissue free amino acids in muscles were measured. Endotoxin induced translocation from the gut lumen to the MLN in all groups, whereas dissemination occurred only in LPS-treated rats. OKG significantly reduced dissemination of the bacteria in the spleen. 3-Methylhistidine excretion was greater in the LPS + Gly group (+25%, P < 0.05) than in either the LPS + OKG or Saline + Gly group. The group fed the OKG-enriched diet had higher muscular glutamine, ornithine and arginine concentrations than did the Gly-supplemented groups (P < 0.05). Intestinal sucrase and aminopeptidase activities were higher in the LPS + OKG group than in the LPS + Gly group (-30%, P < 0.05). OKG supplementation limits bacterial dissemination and metabolic changes after injury in rats and thus may be useful in the prevention of gut-derived sepsis in critically ill patients.


KEY WORDS: • ornithine {alpha}-ketoglutarate • endotoxemia • bacterial translocation • protein catabolism • rats


    INTRODUCTION
 TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
The high incidence of systemic infection after injury in a clinical setting and in different experimental models, together with the specific flora found in such infections, has led to the concept of bacterial translocation (Berg and Garlington 1979Citation , Berg 1992Citation ). The gut was first thought to be of major importance in these situations because it is a large reservoir of microorganisms usually retained by a powerful mucosal barrier (Laissue and Gebbers 1992Citation ). Numerous studies in animals later demonstrated that bacterial translocation is a multifactorial phenomenon. Disruption of the normal ecological balance of the indigenous microflora, resulting in bacterial overgrowth, impaired host immune defenses or physical disruption of the gut mucosal barrier, may promote bacterial translocation (Berg and Garlington 1979Citation , Berg 1992Citation , Deitch and Berg 1987Citation , Deitch et al. 1987aCitation and 1987bCitation , Gennari et al. 1995Citation , Gianotti et al. 1993Citation ). Because these different factors may be related to the nutritional status of the host, subsequent studies have investigated the metabolic changes occurring during infection, i.e., a severe catabolic state and an impaired nitrogen metabolism are often associated with bacterial translocation and dissemination to the extraintestinal organs (Braga et al. 1994Citation , Cerra 1992Citation , Gennari et al. 1995Citation , Gianotti et al. 1994Citation and 1995Citation , Schlegel et al. 1999Citation ).

It has become evident that providing adequate nutritional support can improve the metabolic status and immune defenses in critically ill patients (Braga et al. 1994Citation , Elia 1995Citation , Gennari et al. 1995Citation ). In addition, compared with parenteral nutrition, enteral nutrition may specifically prevent translocation of bacteria from the gut (Braga et al. 1994Citation , Daly et al. 1992Citation , Deitch et al. 1987bCitation , Gianotti et al. 1994Citation ). Supplementing the enteral diet with nutrients known to have trophic effects on enterocytes and to sustain the functionality of immunologic intestinal cells has opened an exciting new area in postsurgical care (Cerra 1992Citation , Cynober 1995Citation and 1999Citation , Daly et al. 1992Citation ). Thus, the use of ornithine {alpha}-ketoglutarate (OKG;3 Cétornan-Laboratoires Chiesi, Courbevoie, France) has attracted attention in recent years. OKG is a salt formed from one molecule of {alpha}-ketoglutarate and two molecules of ornithine. It is quickly dissociated after both parenteral and enteral administration. However, interactions between the metabolic pathways of the two components have been shown, resulting in the formation of glutamine, arginine and proline (Cynober 1991Citation , 1995Citation and 1999Citation ). The beneficial effects of OKG on the nutritional status and protein metabolism have been documented in various catabolic states, including burns, surgery and trauma [for a review, see Cynober (1995)Citation ]. More recently, studies [reviewed in Cynober (1999)Citation ] have also indicated the beneficial effect of OKG on intestinal structure and function, and on cellular immunity.

However, all of the studies described in the literature have focused solely on the metabolic response, the intestinal functions or immunity, and it remains unclear whether OKG limits primarily bacterial translocation, bacterial dissemination or both. The aim of this study was to investigate the effect of enteral OKG supplementation in preventing mucosal functional changes in the jejunum (where ornithine and {alpha}-ketoglutarate are absorbed) and bacterial dissemination. The action of OKG on the host hypercatabolic response was assessed simultaneously by measuring nitrogen balance, urinary 3-methylhistidine excretion and tissue amino acid pools together. For this purpose, a rat model of endotoxemia followed by selective bowel decontamination and bacterial recontamination was used. This model offers the advantages of eliciting a high catabolic response and of mimicking a clinical situation encountered in an intensive care unit (Schlegel et al. 1999Citation ).


    MATERIALS AND METHODS
 TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Animals and animal care.

Male Wistar rats (Center d’élevage René Janvier, St-Denis-les-Laval, France), 4 wk old, weighing 50–75 g on arrival were used (n = 30). They were housed in individual metabolic cages with wire-grid bottoms. Temperature, humidity and light conditions (reversed 12-h light:dark cycle) were controlled automatically. Food (A03, Usine d’Alimentation Rationnelle, Epinay-sur-Orge, France; 13400 kJ/kg, 235 g protein/kg and 37.6 g N/kg) and water were consumed ad libitum during the acclimation period of 4–6 d. The rats were weighed every day to check growth and detect any underlying disease. They were then randomly assigned to three experimental groups as described below.

Two of the investigators (C.C.L. and L.C.) are authorized by the French Ministry for Agriculture to use this model. Animals were housed in a facility approved by the French Ministry for Agriculture.

Experimental design.

At the end of the acclimation period, the rats underwent selective intestinal decontamination with 1 g/kg amoxicillin (SmithKline Beecham, Nanterre, France), 0.2 g/kg streptomycin (Laboratoire Diamant, Puteaux, France), 0.1 g/kg vancomycin (Lilly France SA, Saint-Cloud, France) and 0.05 g/kg amphotericin B (Bristol-Myers Squibb, Paris-La Défense, France) given orally, twice a day, for a total of 4 d (i.e., from d -6 to -2). The Escherichia coli STA strain was prepared as previously described (Schlegel et al. 1999Citation ). On d -2, the rats were inoculated orally with 1010 bacteria/kg body and continued to receive streptomycin alone until the end of the experiment so as to allow a selective advantage to E. coli STA vs. other enteric bacteria. Two days after oral colonization with E. coli (i.e., d 0), lipopolysaccharide (LPS) from E. coli ATCC 12740 serotype O127:B8 (Sigma-Aldrich, St-Quentin-Fallavier, France) was prepared in saline. Rats (n = 22) were given an intraperitoneal LPS injection (3 mg/kg body). Control rats (n = 8), which were antibiotic-decontaminated and colonized by the same E. coli strain, received a saline injection instead of LPS. Food was then withdrawn for 24 h (d 0 to 1) to amplify the LPS-induced hypercatabolism (Schlegel et al. 1999Citation ).

The rats were observed for signs of toxicity (inactivity, ruffled fur, chromodacryorrhea) and mortality for 24 h. On d 1, an enteral nutrition solution (Osmolite, Laboratoires Abbott, Rungis-France, Table 1Citation ) was given intragastrically by gavage three times a day for 48 h as previously described (Le Boucher et al. 1997bCitation and 1997cCitation , Roch-Arweiler et al. 1996Citation ). The enteral nutrition solution was supplemented with either 5.0 g/(kg · d) OKG (LPS + OKG group) or 3.5 g/(kg · d) glycine (LPS + Gly and Saline + Gly groups). Hence, the three experimental groups received isonitrogenous supplemented diets [184 g N/(kg · d)]. The OKG dose was selected according to the literature (Cynober 1995Citation ). Water was consumed ad libitum throughout this period.


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Table 1. Composition of the basal diet administrated enterally to rats1

 
Urine was collected quantatively three times per day, from d 0 to 3, for total urinary nitrogen and 3-methylhistidine determinations. Each morning, the cages were cleaned and a fresh fecal sample was taken to monitor the evolution of the enterobacterial flora. Rats were killed by decapitation on d 3 after endotoxemia.

Evaluation of the postinjury hypermetabolic response.

The thymus and muscle [extensor digitorum longus (EDL) and anterior tibialis] were removed at the time of killing and weighed. The muscle tissue was immediately frozen in liquid nitrogen and stored at -80°C for amino acid analysis. Homogenates were prepared in 10% trichloroacetic acid containing 0.5 mmol/L EDTA (1 mL/100 mg tissue). After centrifugation at 2500 g for 10 min the amino acids were quantified in the supernatants by ion-exchange chromatography (Hitachi L8500A-Sciencetec, Les Ulis, France) as previously described (Le Boucher et al. 1997aCitation ).

Total urinary nitrogen excretion was determined daily by pyrochemiluminescence (Antek 7000N analyzer, Antek, Houston, TX). The nitrogen balance (nitrogen intake - urinary nitrogen losses) was calculated daily and totaled for the 3 d of the experiment. Urinary 3-methylhistidine was measured after hydrolysis (HCl 6 mol/L, 110°C for 24 h) by ion-exchange chromatography (Hitachi L8500A).

Measurement of bacterial translocation.

Mesenteric lymph nodes (MLN), spleen and liver were aseptically removed according to Berg and Garlington (1979)Citation , weighed and homogenized in sterile water. Aliquots of homogenates (100 µL) were plated onto Drigalski gram-negative bacilli selective agar for bacterial counts. After 18 h of aerobic incubation at 37°C, each colony was identified according to its biochemical profile (API 20E, bioMérieux, La Balme-les-Grottes, France) and its antibiotic resistance profile established using a disk diffusion method (Comité de l’Antibiogramme 1998Citation ). The bacterial count was expressed as colony-forming units (cfu) per gram of tissue. The detection limit of the assay was 20 cfu/g.

Jejunal mucosa enzyme activity.

The jejunum was quickly removed and the first 10 cm, starting at the ligament of Treitz, was measured with no traction. This segment was washed with cold NaCl (90 g/L) and gently dried. It was then weighed and everted. The mucosa were removed by scraping with a glass slide onto a chilled plate and frozen in liquid nitrogen before storage at -80°C.

Before analysis, the mucosa were homogenized in phosphate buffer. Enzyme activities for sucrase isomaltase and lactase were measured using a modified method of Dahlqvist as previously described (Cézard et al. 1979) and for neutral brush border aminopeptidase as described by Cézard et al. (1994)Citation . Protein concentrations were assayed by the method of Lowry et al. (1951)Citation . Results are expressed per 10 cm intestine (total activity) and per mg of protein (specific activity).

Statistics.

Qualitative data such as mortality or bacterial translocation incidence among groups were analyzed using the {chi}2 or Fischer’s exact test where appropriate (see Results). Other results are presented as means ± SEM. One-way ANOVA followed by a Newman-Keuls test was used for statistical analysis (PCSM, DeltaSoft, Grenoble, France). Differences were considered significant at P < 0.05.


    RESULTS
 TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
During antibiotic decontamination, the rats exhibited normal growth (Fig. 1Citation ), indicating that the manipulation of the flora had no deleterious effect per se. The 2nd day after E. coli administration was chosen for the LPS injury because the bacterial population had reached a high and stable level by this day (Fig. 1)Citation . Throughout the experimental period, we did not find any differences among groups in body weight or fecal bacterial population, which supports the presentation of a single statistical mean for all rats in Figure 1Citation . On the day after the endotoxin injection, the rats were lethargic, their eyes were closed and their fur ruffled. Three deaths occurred, all in the LPS + Gly group. Surviving LPS-treated rats promptly recovered and, at the time of killing, displayed no signs of intestinal distension.



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Figure 1. Body weight and fecal Escherichia coli population in rats treated with antibiotics injected with either lipopolysaccharide (LPS) or saline, with Osmolite supplemented with 1.84 g N/(kg · d) in the form of either glycine (LPS + Gly and saline + Gly) or ornithine {alpha}-ketoglutarate (LPS + OKG), deprived of food for 24 h and then refed. There were no differences among the experimental groups for these two variables; thus, a single mean ± SEM for all rats studied is presented (n = 23).

 
The LPS-injected rats had a significantly greater nitrogen loss, resulting in a lower nitrogen balance (Fig. 2Citation ) in the first 24 h compared with the Saline controls. On d 2, the LPS + Gly rats had a significantly lower nitrogen balance than did either the Saline + Gly or LPS + OKG groups (P = 0.03). In the Saline + Gly, LPS + Gly and LPS + OKG groups, cumulative 3-methylhistidine excretion was 5402 ± 145, 6791 ± 305 and 5790 ± 447 µmol/3 d (P < 0.05, LPS + Gly vs. Saline + Gly and LPS + OKG), respectively. Relative thymus weights were lower, and spleen and liver relative weights were higher in the LPS + Gly group than in the LPS + OKG–supplemented rats (Table 2Citation ). The anterior tibialis, EDL and jejunal mucosa tissue weights did not differ among groups (Table 2)Citation . The concentrations of glutamine and other OKG-related amino acids (arginine, glutamate, proline, citrulline and ornithine) were significantly greater in the anterior tibialis of rats after OKG administration than after Gly (Table 3Citation ). A similar pattern was found in EDL (data not shown). Free amino acid levels in the jejunal mucosa did not differ among groups (data not shown).



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Figure 2. Evolution of nitrogen balance in rats treated with antibiotics injected with either lipopolysaccharide (LPS) or saline (control), with Osmolite supplemented with 1.84 g N/(kg · d) in the form of either glycine (LPS + Gly and saline + Gly groups) or ornithine {alpha}-ketoglutarate (LPS + OKG group), food deprived for 24 h and then refed. Data are presented as the mean ± SEM, n = 7 (LPS + Gly) or 8 (Saline + Gly and LPS + OKG). Different superscripts at a time indicate significantly different means, P < 0.05.

 

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Table 2. Relative organ weights on the day of killing in rats treated with antibiotics, inoculated with Escherichia coli, injected with either lipopolysaccharide (LPS) or saline, deprived of food for 24 h and then refed with Osmolite supplemented with 1.84 g N/(kg · d) in the form of either glycine (LPS + Gly and saline + Gly) or ornithine {alpha}-ketoglutarate (LPS + OKG)1

 

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Table 3. Free amino acid concentrations in the anterior tibialis of rats treated with antibiotics, inoculated with Escherichia coli, injected with either lipopolysaccharide (LPS) or saline, deprived of food for 24 h and then refed with Osmolite supplemented with 1.84 g N/(kg · d) in the form of either glycine (LPS + Gly and saline + Gly) or ornithine {alpha}-ketoglutarate (LPS + OKG)1

 
Bacteria identified in the tissues were similar to the inoculated strain as determined by their biochemical identification and resistance to antibiotics. The magnitude (i.e., number of bacteria/g of tissue) of translocation to the MLN did not differ among the groups treated with LPS + Gly or LPS + OKG and the control (Saline + Gly) group (168 ± 84 and 188 ± 115, respectively, vs. 83 ± 54 cfu/g tissue, P = 0.09). Dissemination to the spleen was significantly higher in the LPS + Gly group than in the LPS + OKG and Saline + Gly groups (Table 4Citation ).


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Table 4. Incidence of bacterial translocation and dissemination after injury in rats treated with antibiotics, inoculated with Escherichia coli, injected with either lipopolysaccharide (LPS) or saline, deprived of food for 24 h and then refed with Osmolite supplemented with 1.84 g N/(kg · d) in the form of either glycine (LPS + Gly and saline + Gly) or ornithine {alpha}-ketoglutarate (LPS + OKG)

 
Total enzymatic activities of sucrase, lactase and N-aminopeptidase, and protein concentrations were not altered in the total jejunal mucosa by LPS injection (data not shown). The specific activities of sucrase and N-aminopeptidase were lower in the LPS + Gly group than in the LPS + OKG group (Fig. 3Citation ).



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Figure 3. Enzyme specific activities in the jejunal mucosal homogenates of rats treated with antibiotics injected with either lipopolysaccharide (LPS) or saline (control), with Osmolite supplemented with 1.84 g N/(kg · d) in the form of either glycine (LPS + Gly and saline + Gly groups) or ornithine {alpha}-ketoglutarate (LPS + OKG group), deprived of for 24 h and then refed. Data are presented as the mean ± SEM, n = 7 (LPS + Gly) or 8 (Saline + Gly and LPS + OKG). Different superscripts at a time indicate significantly different means, P < 0.05.

 

    DISCUSSION
 TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Methodological considerations.

The experimental model we designed (Schlegel et al. 1999Citation ), using endotoxemia as the injury after decontamination and recontamination of the gut, associates a severe catabolic response with an increased susceptibility to gut-derived infection in rats. This model mimics a situation encountered in intensive care units [see Schelgel (1999)Citation ]).Weanling rats were selected because they are more sensitive to injury than adult rats (Cynober 1989Citation , Vaubourdolle et al. 1991Citation ). Our experimental protocol led to a bacterial overpopulation on the day of injury (i.e., LPS administration) sufficient to enhance bacterial translocation (Berg and Garlington 1979Citation , Berg 1992Citation , Schlegel et al. 1999Citation ). Increased 3-methylhistidine excretion and a reduction in the intramuscular free glutamine pool were observed in our model for as long as 72 h postinjury. These changes are similar to alterations usually observed in injured rats and indicate that a long-lasting hypercatabolic state was achieved (Austgen et al. 1991Citation , Vaubourdolle et al. 1991Citation ).

Previous studies have demonstrated the efficacy of OKG supplementation on postinjury metabolic response (Dumas et al. 1998Citation , Le Boucher et al. 1997bCitation , Vaubourdolle et al. 1991Citation ). The optimal regimen for OKG administration remains undefined, but the dose of 5 g/(kg · d) was used by most investigators (Cynober 1995Citation ) as a pharmacologic dose in rats. Additional results have recently shown an OKG dose-response effect on free glutamine and nitrogen metabolism in tissues (Pernet et al. 1999Citation ). Reduction of nitrogen losses and impairment of myofibrillar catabolism, together with an increase in glutamine concentration in tissues, are consistent with the changes previously observed in similar models of endotoxemia in rats (Le Boucher et al. 1997bCitation , Pernet et al. 1999Citation , Vaubourdolle et al. 1991Citation ). However, none of these studies have simultaneously explored the metabolic, trophic and immunologic effects of OKG in a unique and well-defined animal model of experimental injury.

Effect of OKG on bacterial translocation and dissemination.

The occurrence of bacterial translocation to the MLN in noninjured animals was previously observed in similar models in rats or mice (Deitch and Berg 1987Citation , Deitch et al. 1987aCitation , Kalfarentzos et al. 1996Citation ). It was assumed to be a part of the normal antigenic stimulation of the gut-associated lymphoid tissue in the absence of injury (Berg and Garlington 1979Citation , Berg 1992Citation , Laissue et al. 1992Citation ). In our model (Schlegel et al. 1999Citation ), the LPS injection did not actually induce bacterial translocation because it occurred at the same level in the saline controls; more specifically, it led to the dissemination of bacteria to the extraintestinal organs such as the spleen and liver. We (Schelgel et al. 1999Citation ) and others (Deitch et al. 1987bCitation , Gianotti et al. 1993Citation , 1994Citation and 1995Citation ) have postulated that bacterial translocation, dissemination and infection occurring after injury involve both impairment of the gut barrier and a failure and suppression of the local specific immune response. The simultaneous reduction of thymic weight and increase in spleen and liver weights in our model suggest a redistribution of the lymphoid cells from the lymphoid central compartment to splanchnic areas. Our observations are consistent with the results of other studies (Lasnier et al. 1996Citation , Torre et al. 1993Citation ). We hypothesized that the adaptive response to injury was not efficient in LPS + Gly-treated rats because the bacterial dissemination occurred to a large extent in that group. Dissemination may be considered to be a direct consequence of a functional defect in the immune cells (Gianotti et al. 1994Citation , Kalfarentzos et al. 1996Citation , Xu et al. 1998Citation ). Oral supplementation with OKG counteracts a reduction of thymic weight, an increase of spleen or liver weight, and simultaneously reduces bacterial dissemination after an endotoxin injection in rats. These protective effects were observed previously in experimental models of endotoxemia (Lasnier et al. 1996Citation ), radiation-induced enterocolitis (Kalfarentzos et al. 1996Citation ), small bowel resection (Czernichow et al. 1997Citation , Dumas et al. 1998Citation ) or transplantation (de Oca et al. 1997Citation ). OKG has been demonstrated to display immunostimulating properties, improving the oxidative burst of neutrophil polymorphonuclear cells (Moinard et al. 1999Citation , Roch-Arveiller et al. 1996Citation ) and immune cell responses (Albina 1993Citation , Moinard et al. 2000Citation , Robinson et al. 1999Citation ) in rat models of burn, cancer or dexamethasone treatment. Thus, we speculate that OKG is responsible for a better host response against infection originating from the gut through its action on the immune cells involved in the defense of the organism. In addition, OKG supplementation may preserve the functionality and integrity of the intestinal mucosal barrier because it was effective in improving the restitution of a normal mucosal architecture (Dumas et al. 1998Citation , Raul et al. 1995Citation ) and in reducing degenerative changes after injury (Czernichow et al. 1997Citation , Kalfarentzos et al. 1996Citation ).

OKG action of intestine functionality.

Although changes in the intestinal architecture after endotoxemia and refeeding have been studied extensively (Deitch and Berg 1987Citation , Deitch et al. 1987aCitation and 1987bCitation , Dumas et al. 1998Citation , Raul et al. 1995Citation ), the effects of injury and OKG supplementation on enzymatic activities of the enterocytes are less well known. This study shows that endotoxemia is associated with reduced specific activities of sucrase and N-aminopeptidase, an effect that is counteracted in part by OKG administration. Previous studies have implicated either a reduction in both number and height of the villi, or a delayed enzymatic differentiation during epithelial cell migration from the crypt to the villus, through a reduction of disaccharidase activities (Holt et al. 1985Citation , Lee et al. 1997Citation , Raul et al. 1995Citation ). Interestingly, OKG had a stimulating effect on villous height in both the jejunum and ileum (Czernichow et al. 1997Citation , Dumas et al. 1999Citation , Kalfarentzos et al. 1996Citation , Raul et al. 1995Citation ). Because our study was limited to the jejunal segment of the intestine, and also because we studied total mucosal homogenates instead of the purified brush border membrane, we may have observed a limited effect of injury and treatment on the enzymatic activities. In addition, some studies using the resection model (Czernichow et al. 1997Citation , Zaouch et al. 2000Citation ) indicate that the extent of both the morphological and functional adaptive response of the gut to injury may be limited after 4 d and may have occurred between 4 and 7 d after injury. These preliminary results warrant further cellular and molecular studies to explore the regulation of the intestinal disaccharidase activity in trauma and the mechanism of action of OKG.

In conclusion, we demonstrate here for the first time in a single study that OKG administration in injured rats significantly reduces both the hypercatabolic response, and immunologic and functional defects of the intestinal cells. OKG contributes to a better adaptive response to injury as shown by a limitation of bacterial dissemination and subsequent reduction of hypercatabolism and muscular protein wasting. These results suggest that critically ill patients, admitted shortly after injury, might benefit from the addition of OKG to their enteral diet with the goal of reducing gut-derived sepsis and the occurrence of infected multiple-system organ failures.


    FOOTNOTES
 
1 Supported in part by a grant from Laboratoires Chiesi, Courbevoie, France. Back

3 Abbreviations used: cfu, colony forming units; EDL, extensor digitorum longus; Gly, glycine; LPS, lipopolysaccharide, MLN, mesenteric lymph nodes; OKG, ornithine {alpha}-ketoglutarate. Back

Manuscript received March 27, 2000. Initial review completed May 23, 2000. Revision accepted August 28, 2000.


    REFERENCES
 TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

1. Albina J. E. Ornithine {alpha}-ketoglutarate enhances macrophages tumor cytotoxicity. Clin. Nutr. 1993;12(suppl.):2(abs.)

2. Austgen T. R., Chen M. K., Flynn T. C., Souba W. W. The effect of endotoxin on the splanchnic metabolism of glutamine and related substrates. J. Trauma 1991;31:742-752[Medline]

3. Berg R. D. Translocation of enteric bacteria in health and disease. Curr. Stud. Hematol. Blood Transfus. 1992;59:44-65

4. Berg R. D., Garlington A. W. Translocation of certain indigenous bacteria from the gastrointestinal tract to the mesenteric lymph nodes and other organs in gnotobiotic mouse model. Infect. Immunol. 1979;23:403-411[Abstract/Free Full Text]

5. Braga M., Gianotti L., Costantini E., di Francesco A., Socci C., Paganelli G., Ossi C., di Carlo V. Impact of enteral nutrition on intestinal bacterial translocation and mortality in burned mice. Clin. Nutr. 1994;13:256-261

6. Cerra F. B. Role of nutrition in the management of malnutrition and immune dysfunction of trauma. J. Am. Coll. Nutr. 1992;11:512-518[Abstract]

7. Cézard J. P., Conklin K. A., Das B. C., Gray G. M. Incomplete intracellular forms of intestinal surface membrane sucrase-isomaltase. J. Biol. Chem. 1979;254:8969-8975[Free Full Text]

8. Cézard J. P., Tran T. A., Macry J., Zarrabian S., Roger L., Bressolier P., Julien R., Mendy F., Kahn J. M. Effect of two protein hydrolysates on growth, nitrogen balance and small intestine adaptation in growing rats. Biol. Neonate 1994;65:60-67[Medline]

9. Comité de l’Antibiogramme de la Société Française de Microbiologie Communiqué 1998. Path. Biol. 1998;46:I-XVI(En encart)

10. Cynober L. Amino acid metabolism in thermal burns. J. Parent. Enteral Nutr. 1989;13:196-205[Abstract]

11. Cynober L. Ornithine {alpha}-ketoglutarate in nutritional support. Nutrition 1991;7:313-322[Medline]

12. Cynober L. Ornithine {alpha}-ketoglutarate. Cynober L. eds. Amino Acid Metabolism and Therapy in Health and Nutritional Disease 1995:385-395 CRC Press Boca Raton, FL.

13. Cynober L. The use of {alpha}-ketoglutarate salts in clinical nutrition and metabolic care. Curr. Opin. Clin. Nutr. Metab. Care 1999;2:33-37[Medline]

14. Czernichow B., Nsi-Emvo E., Galluser M., Gossé F., Raul F. Enteral supplementation with ornithine {alpha}-ketoglutarate improves the early adaptative response to resection. Gut 1997;40:67-72[Abstract/Free Full Text]

15. Daly J. M., Lieberman M. D., Goldfine J., Shou J., Weitraub F., Rosato E. F., Lavin P. Enteral nutrition with supplemental arginine, RNA, and omega-3 fatty acids in patients after operation: immunologic, metabolic, and clinical outcome. Surgery 1992;112:56-67[Medline]

16. Deitch E. A., Berg R. D. Endotoxin but not malnutrition promotes bacterial translocation of the gut flora in burned mice. J. Trauma 1987;27:161-166[Medline]

17. Deitch E. A, Berg R. D., Specian R. Endotoxin promotes the translocation of bacteria from the gut. Arch. Surg. 1987a;122:185-190[Abstract]

18. Deitch E. A., Winteston J., Li M., Berg R. D. The gut as a portal of entry for bacteria, role of protein malnutrition. Ann. Surg. 1987b;205:681-692[Medline]

19. de Oca J., Bettonica C., Cuadrado S., Vallet J., Martin E., Garcia A., Montanes T., Jaurrieta E. Effect of oral supplementation of ornithine {alpha}-ketoglutarate on the intestinal barrier after orthotopic small bowel transplantation. Transplantation 1997;63:436-439[Medline]

20. Dumas F., De Bandt J. P., Colomb V., Le Boucher J., Coudray-Lucas C., Lavie S., Brousse N., Ricour C., Cynober L. Enteral ornithine {alpha}-ketoglutarate enhances intestinal adaptation to massive resection in rats. Metabolism 1998;47:1366-1371[Medline]

21. Elia M. Changing concepts of nutrient requirements in disease: implications for artificial nutritional support. Lancet 1995;345:1279-1284[Medline]

22. Gennari R., Alexander J., Eaves-Pyles T. Effect of different combinations of dietary additives on bacterial translocation and survival in gut-derived sepsis. J. Parent. Enteral Nutr. 1995;19:319-325[Abstract]

23. Gianotti L., Alexander J. W., Gennari R., Pyles T., Babcock G. F. Oral glutamine decreases bacterial translocation and improves survival in experimental gut-origin sepsis. J. Parent. Enteral Nutr. 1995;19:69-74[Abstract]

24. Gianotti L., Alexander J., Pyles T., James L., Babcock G. F. Relationship between extent of burn injury and magnitude of microbial translocation from the intestine. J. Burn Care Rehabil. 1993;14:336-342[Medline]

25. Gianotti L., Nelson J., Alexander J. W., Chalk C. L., Pyles T. Post-injury hypermetabolic response and magnitude of translocation: prevention by early enteral nutrition. Nutrition 1994;10:225-231[Medline]

26. Holt P. R., Tierney A. R., Kolter D. P. Delayed enzyme expression, a defect of aging rat gut. Gastroenterology 1985;89:1026-1034[Medline]

27. Kalfarentzos F., Spiliotis J., Melachrinou M., Katsarou C., Spiliopoulou I., Panagopoulos C., Alexandrides T. H. Oral ornithine {alpha}-ketoglutarate accelerates healing of the small intestine and reduces bacterial translocation after abdominal radiation. Clin. Nutr. 1996;15:29-33[Medline]

28. Laissue J. A., Gebbers J. O. The intestinal barrier and the gut associated lymphoid tissue. Curr. Stud. Hematol. Blood Transfus. 1992;59:19-43

29. Lasnier E., Coudray-Lucas C., Le Boucher J., Jardel A., Cynober L. Ornithine alpha-ketoglutarate counteracts thymus involution and glutamine depletion in endotoxemic rats. Clin. Nutr. 1996;15:197-200[Medline]

30. Le Boucher J., Charret C., Couday-Lucas C., Giboudeau J., Cynober L. Amino acid determination in biological fluids by automated ion-exchange chromatography: performance of Hitachi L-8500A. Clin. Chem. 1997a;43:1421-1428[Abstract/Free Full Text]

31. Le Boucher J., Coudray-Lucas C., Lasnier E., Jardel A., Ekindjian O. G., Cynober L. Enteral administration of ornithine {alpha}-ketoglutarate or arginine {alpha}-ketoglutarate: a comparative study of their effects on glutamine pools in burn-injured rats. Crit. Care Med. 1997b;25:293-298[Medline]

32. Le Boucher J., Obled C., Farges M. C., Cynober L. Ornithine {alpha}-ketoglutarate modulates tissue protein metabolism in burn-injured rats. Am. J. Physiol. 1997c;273:E557-E563[Abstract/Free Full Text]

33. Lee M. F., Russell R. M., Montgomery R. K., Krasinski S. D. Total intestinal lactase and sucrase activities are reduced in aged rats. J. Nutr. 1997;121:1382-1387

34. Lowry O. H., Rosebrough N. J., Farr A. L. Protein measurement with the Folin phenol reagent. J. Biol. Chem. 1951;193:265-275[Free Full Text]

35. Moinard C., Chauveau B., Walrand S., Felgines C., Chassagne J., Caldefie F., Cynober L., Vasson M. P. Phagocyte functions in stressed rats: comparison of modulation by glutamine, arginine and ornithine 2-oxoglutarate. Clin. Sci. (Lond.) 1999;97:59-65[Medline]

36. Moinard C., Caldefie F., Walrand S., Felgines C., Vasson M. P., Cynober L. Involvement of glutamine, arginine, and polyamines in the action of ornithine {alpha}-ketoglutarate on macrophage functions in stressed rats. J. Leukoc. Biol. 2000;67:834-840[Abstract]

37. Pernet P., Coudray-Lucas C., Jardel A., Gillet C., Cynober L. Ornithine {alpha}-ketoglutarate dose-response effect on tissue glutamine concentrations and nitrogen metabolism after injury. Clin. Nutr. 1999;18(suppl. 1):43(abs.)

38. Raul F., Gossé F., Galluser M., Hasselmann M., Seiler N. Functional and metabolic changes in intestinal mucosa of rats after enteral administration of ornithine {alpha}-ketoglutarate salt. J. Parent. Enteral Nutr. 1995;19:145-150[Abstract]

39. Robinson L. E., Bussière F. I., Le Boucher J., Farges M. C., Cynober L., Field C. J., Baracos V. E. Amino acid nutrition and immune function in tumour-bearing rats: a comparison of glutamine-, arginine- and ornithine 2-oxoglutarate-supplemented diets. Clin. Sci. (Lond.) 1999;97:657-669[Medline]

40. Roch-Arveiller M., Tissot M., Coudray-Lucas C., Fontagne J., Le Boucher J., Giroud J. P., Cynober L. Immunomodulatory effects of ornithine {alpha}-ketoglutarate in the rats with burn injury. Arch. Surg. 1996;131:718-723[Abstract]

41. Schlegel L., Coudray-Lucas C., Barbut F., Le Boucher J., Pernet P., Cynober L. Bacterial dissemination, rather than translocation, mediates hypermetabolic response in endotoxemic rats. Crit. Care Med. 1999;27:1511-1516[Medline]

42. Torre P. M., Ronnenberg A. G., Hartman W. J., Prior R. L. Oral arginine supplementation does not affect lymphocyte proliferation during endotoxin-induced inflammation in rats. J. Nutr. 1993;123:481-483

43. Vaubourdolle M., Coudray-Lucas C., Jardel A., Ziegler F., Ekindjian O. G., Cynober L. Action of enterally administrated ornithine {alpha}-ketoglutarate on protein breakdown in skeletal and liver of burned rat. J. Parent. Enteral Nutr. 1991;15:517-520[Abstract]

44. Xu D. Z., Lu Q., Deitch E. A. Elemental diet-induced bacterial translocation associated with systemic and intestinal immune suppression. J. Parent. Enteral Nutr. 1998;22:37-41[Abstract]

45. Zaouche A., Loukil C., de Lagausie P., Peuchmar M., Macry J., Fitoussi F., Bernascomi P., Bingen E., Cézard J. P. Effects of oral Saccharomyces boulardii on bacterial overgrowth, translocation, and intestinal adaptation after small-bowel resection in rats. Scand. J. Gastroenterol. 2000;2:160-165





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