Protective Effects of Glutamine and Leucine Supplementation on Sepsis-Induced Skeletal Muscle Injuries.

This study investigated the effects of l-glutamine (Gln) and/or l-leucine (Leu) administration on sepsis-induced skeletal muscle injuries. C57BL/6J mice were subjected to cecal ligation and puncture to induce polymicrobial sepsis and then given an intraperitoneal injection of Gln, Leu, or Gln plus Leu beginning at 1 h after the operation with re-injections every 24 h. All mice were sacrificed on either day 1 or day 4 after the operation. Blood and muscles were collected for analysis of inflammation and oxidative damage-related biomolecules. Results indicated that both Gln and Leu supplementation alleviated sepsis-induced skeletal muscle damage by reducing monocyte infiltration, calpain activity, and mRNA expression levels of inflammatory cytokines and hypoxia-inducible factor-1α. Furthermore, septic mice treated with Gln had higher percentages of blood anti-inflammatory monocytes and muscle M2 macrophages, whereas Leu treatment enhanced the muscle expressions of mitochondrion-related genes. However, there were no synergistic effects when Gln and Leu were simultaneously administered. These findings suggest that both Gln and Leu had prominent abilities to attenuate inflammation and degradation of skeletal muscles in the early and/or late phases of sepsis. Moreover, Gln promoted the switch of leukocytes toward an anti-inflammatory phenotype, while Leu treatment maintained muscle bioenergetic function.

Parenteral glutamine supplementation improves serum albumin values in surgical cancer patients.

INTRODUCTION: Patients with gastric adenocarcinoma (GA) often develop malnutrition, which deteriorates after cancer surgery and negatively affects surgical outcomes. Despite being an abundant and versatile amino acid involved in the immune system and metabolic functions, glutamine levels are significantly depleted among patients who are critically ill or hypercatabolic. Therefore, this study aimed to investigate whether parenteral glutamine supplementation may improve nutritional status and surgical outcomes. METHODS: This retrospective, single-center cohort study included patients with GA who underwent gastrectomy between January 2007 and June 2019. Patients were classified into either the non-glutamine or glutamine group. Propensity score matching was used to minimize the bias in patient demographics. Furthermore, the average parenteral glutamine dose from the day of surgery to postoperative day four was calculated in g/kg/day. Surgical outcomes (length of hospitalization, major complication, and mortality) and changes in lymphocyte count and serum albumin levels 7 days post-surgery were assessed in both matched groups using adjusted models. RESULTS: A total of 1950 patients were reviewed, among whom 522 (26.8%) received parenteral glutamine supplementation (glutamine dose ranging from 0.05 to 0.49 g/kg/day). Among the included patients, 57.2% were males, and the median age was 64.9 years. After matching, there were 478 cases in each group. No differences in surgical outcomes and changes in lymphocyte count were observed between both matched groups. The glutamine group exhibited a smaller decrease in serum albumin levels compared to the non-glutamine group (-0.6 vs. -1.1 g/dL; P < 0.001). The adjusted matched model showed that glutamine dose contributed significantly toward increasing serum albumin levels (coefficient = 0.08 per 0.1 g/day/kg increment in glutamine; 95% confidence interval: 0.04 to 0.10; P < 0.001). CONCLUSIONS: Perioperative parenteral glutamine supplementation had a positive dose-dependent impact on the recovery of serum albumin levels among patients with GA undergoing gastrectomy, implying that glutamine supplementation improved postoperative nutritional suppression and ameliorated stress-associated inflammation. Although glutamine supplementation was not associated with surgical outcomes, further studies should be conducted to evaluate the clinical significance of serum albumin restoration.

Intravenous Arginine Administration Downregulates NLRP3 Inflammasome Activity and Attenuates Acute Kidney Injury in Mice with Polymicrobial Sepsis.

Acute kidney injury (AKI) is a major complication of sepsis. Nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasomes are multiprotein complexes that mediate septic AKI. L-arginine (Arg) is a conditionally essential amino acid in catabolic conditions and a substrate for nitric oxide (NO) production; however, its use in sepsis is controversial. This study investigated the effect of intravenous Arg supplementation on modulating NLRP3 inflammasome activity in relation to septic AKI. Mice were divided into normal control (NC), sham, sepsis saline (SS), and sepsis Arg (SA) groups. In order to investigate the role of NO, L-N6-(1-iminoethyl)-lysine hydrochloride (L-NIL), an inducible NO synthase inhibitor, was administered to the sepsis groups. Sepsis was induced using cecal ligation and puncture (CLP). The SS and SA groups received saline or Arg via tail vein 1 h after CLP. Mice were sacrificed at 6, 12, and 24 h after sepsis. The results showed that compared to the NC group, septic mice had higher plasma kidney function parameters and lower Arg levels. Also, renal NLRP3 inflammasome protein expression and tubular injury score increased. After Arg treatment, plasma Arg and NO levels increased, kidney function improved, and expressions of renal NLRP3 inflammasome-related proteins were downregulated. Changes in plasma NO and renal NLRP3 inflammasome-related protein expression were abrogated when L-NIL was given to the Arg sepsis groups. Arg plus L-NIL administration also attenuated kidney injury after CLP. The findings suggest that intravenous Arg supplementation immediately after sepsis restores plasma Arg levels and is beneficial for attenuating septic AKI, partly via NO-mediated NLRP3 inflammasome inhibition.

Antecedent Dietary Glutamine Supplementation Benefits Modulation of Liver Pyroptosis in Mice with Polymicrobial Sepsis.

The liver is the main organ responsible for bacterial and endotoxin clearance. Pyroptosis is a form of proinflammatory programmed cell death activated by caspase-1/11 and gasdermin D (GadD). Pyroptosis protects the host against bacterial infection; however, overactive pyroptosis can lead to organ injury. Glutamine (GLN) is a specific amino acid with anti-inflammatory and immunomodulatory properties. This study investigated the effects of GLN pretreatment on liver pyroptosis in a mouse model of polymicrobial sepsis. Mice were assigned to sham, sepsis control (Sepsis-C), and sepsis GLN (Sepsis-G) groups. The sham and Sepsis-C groups were fed the AIN-93G diet. The Sepsis-G group was provided with identical diet components except that part of the casein was replaced by GLN. After feeding the respective diets for 2 weeks, a cecal ligation and puncture (CLP) procedure was performed in the sepsis groups. An antibiotic was administered after CLP. Mice were sacrificed at either 24 or 72 h after CLP. The results showed that sepsis resulted in upregulated liver caspase-1/11 expression. Compared to the Sepsis-C group, the Sepsis-G group had higher liver caspase-11 and NLRP3 gene expressions at 24 h and lower active caspase-1/11 and cleaved GadD protein levels at 72 h after sepsis. Additionally, liver inflammatory cytokine gene expressions had decreased by 72 h post-CLP. The findings suggest that prophylactic administration of GLN initially upregulated liver pyroptosis to eradicate pathogens, yet the process of pyroptosis was suppressed in the late phase of sepsis. This may have beneficially attenuated liver inflammation and injury in an antibiotic-treated septic condition.

Randomized controlled clinical trial assessing the effects of oral nutritional supplements in postoperative gastric cancer patients.

BACKGROUND: Postoperative weight loss and malnutrition are major issues in gastric cancer patients. The concept of oral nutritional supplements (ONS) is gaining widespread acceptance. We investigated the effects of ONS administration on postoperative body weight loss in patients with gastric cancer who had undergone total gastrectomy or distal gastrectomy. METHODS: Patients were randomized to either the treatment or the control group. In both groups, standard surgery for gastric cancer was performed. In the treatment group, intervention with ONS was performed until 12 weeks after discharge. In the control group, patients were fed the usual postoperative diet. Weight, body composition, quality of life, hematological parameters, and blood chemistry were evaluated. RESULTS: We analyzed 113 cases (73 distal gastrectomy, 40 total gastrectomy). Weight loss in the ONS group after total gastrectomy was significantly less than that in the control group. Weight loss and skeletal muscle mass loss after distal gastrectomy did not differ significantly between the ONS and control groups. CONCLUSION: This study showed ONS after total gastrectomy to significantly diminish postoperative weight loss.

Prospective double-blind randomized study on the efficacy and safety of an n-3 fatty acid enriched intravenous fat emulsion in postsurgical gastric and colorectal cancer patients.

BACKGROUND: A lipid emulsion composed of soybean oil (long-chain triglycerides, LCT), medium-chain triglycerides (MCT) and n-3 poly-unsaturated fatty acids (PUFAs) was evaluated for immune-modulation efficacy, safety, and tolerance in patients undergoing major surgery for gastric and colorectal cancer. METHODS: In a prospective, randomized, double-blind study, 99 patients with gastric and colorectal cancer receiving elective surgery were recruited and randomly assigned to either the study group, receiving the n-3 PUFAs enriched intravenous fat emulsion (IVFE), or the control group, receiving a lipid emulsion comprised of soybean oil and MCTs (0.8 - 1.5 g · kg-1 · day-1) as part of total parenteral nutrition (TPN) regimen from surgery (day -1) up to post-operative day 7. Safety and efficacy parameters were assessed on day -1 and post-operative visits on day 1, 3, and 7. Adverse events were documented daily and compared between the groups. RESULTS: Pro-inflammatory markers, laboratory parameters, and adverse events did not differ prominently between the 2 groups, with the exception of net changes (day 7 minus day -1) of free fatty acids (FFAs), triglyceride, and high-density lipoprotein (HDL). Net decrease of FFAs was remarkably higher in the study group, while the net increase of triglyceride and decrease of HDL was significantly lower. CONCLUSIONS: The n-3 PUFA-enriched IVFE showed improvements in lipid metabolism. In respect of efficacy, safety and tolerance both IVFE were comparable. In patients with severe stress, there is an inflammation-attenuating effect of n-3 PUFAs. Further, adequately powered clinical trials will be necessary to address this question in postsurgical GI cancer patients. TRIAL REGISTRATION: US ClinicalTrials.gov NCT00798447.

Glutamine supplementation attenuates expressions of adhesion molecules and chemokine receptors on T cells in a murine model of acute colitis.

BACKGROUND: Migration of T cells into the colon plays a major role in the pathogenesis in inflammatory bowel disease. This study investigated the effects of glutamine (Gln) supplementation on chemokine receptors and adhesion molecules expressed by T cells in mice with dextran sulfate sodium- (DSS-) induced colitis. METHODS: C57BL/6 mice were fed either a standard diet or a Gln diet replacing 25% of the total nitrogen. After being fed the diets for 5 days, half of the mice from both groups were given 1.5% DSS in drinking water to induce colitis. Mice were killed after 5 days of DSS exposure. RESULTS: DSS colitis resulted in higher expression levels of P-selectin glycoprotein ligand- (PSGL-) 1, leukocyte function-associated antigen- (LFA-) 1, and C-C chemokine receptor type 9 (CCR9) by T helper (Th) and cytotoxic T (Tc) cells, and mRNA levels of endothelial adhesion molecules in colons were upregulated. Gln supplementation decreased expressions of PSGL-1, LFA-1, and CCR9 by Th cells. Colonic gene expressions of endothelial adhesion molecules were also lower in Gln-colitis mice. Histological finding showed that colon infiltrating Th cells were less in the DSS group with Gln administration. CONCLUSIONS: Gln supplementation may ameliorate the inflammation of colitis possibly via suppression of T cell migration.

Randomized clinical trial of new intravenous lipid (SMOFlipid 20%) versus medium-chain triglycerides/long-chain triglycerides in adult patients undergoing gastrointestinal surgery.

BACKGROUND: SMOFlipid 20% is intravenous lipid emulsion (ILE) containing long-chain triglycerides (LCT), medium-chain triglycerides (MCT), olive oil, and fish oil as a mixed emulsion containing α-tocopherol. The aim was to assess the efficacy of this new ILE in gastrointestinal surgery compared with MCT/LCT. METHODS: In this prospective study, 40 patients were randomized to SMOFlipid 20% or MCT/LCT (Lipovenoes 20%) group. Clinical and biochemistry data were collected. Inflammatory markers (CRP, IL-6, IL-10, TNF-α, TGF-ß1) and oxidative stress (ROS and superoxide) were measured. RESULTS: Thirty-five patients (17 males and 18 females) with a mean age of 57 years completed the study. The patients' demographic characteristics (age, gender, height, body weight, and BMI) were similar without significant differences between groups. The increment of triglyceride on day 6 from baseline was significantly lower in SMOFlipid group than in Lipovenoes MCT/LCT group. Inflammatory markers, as well as superoxide radical and total oxygen radical were not different between groups. CONCLUSIONS: Despite the comparable effect on inflammatory response, because of its well-balanced fatty acid pattern, relatively low n-6:n-3 ratio, and high vitamin E content, SMOFlipid had a better triglyceride-lowering effect as compared with MCT/LCT in adult patients undergoing gastrointestinal surgery.

Parenteral glutamine supplement has synergic effects in minimally invasive surgery of subtotal gastrectomy patients.

BACKGROUND/AIMS: Exogenous glutamine supplement is known to improve morbidity and mortality of critically-ill patients. This study was conducted to elucidate the role of glutamine in minimally invasive surgery. METHODOLOGY: We retrospectively reviewed subtotal gastrectomy patients in National Taiwan University Hospital from Dec 2005 to Dec 2008. The patients were divided into three groups. Group 1 underwent subtotal gastrectomy by laparotomy without glutamine supplement, group 2 underwent subtotal gastrectomy by laparotomy with glutamine supplement and group 3 underwent gasless laparoscopy-assisted subtotal gastrectomy with parenteral glutamine supplement. RESULTS: There were 155 patients in total; 85 patients in group 1, 17 in group 2 and 53 in group 3. The mean flatus days after operation are 3.6, 3.1 and 2.8 for groups 1, 2 and 3, respectively (p=0.001). Oral intake after operation was commenced after 6.7, 5.0 and 4.7 days (p=0.006). The body temperature had borderline differences between groups 3 and 1. There were significant differences in postoperative systemic responses including heart rates (p<0.001) and tenderness (p=0.011) 5 days after operation for group 3 vs. group 1. Minimally invasive surgery was a negative factor for postoperative body temperature change. Glutamine was a significant factor for postoperative heart rate change and reduction of tenderness. CONCLUSIONS: Glutamine supplement may have synergic effects of rapid recovery in minimal invasive surgery for subtotal gastrectomy patients by minimizing the postoperative systemic response and accelerating recovery.

Effects of parenteral glutamine supplementation on modulating the immune response in rats undergoing a total gastrectomy.

The present study investigated the effect of parenteral glutamine (Gln) supplementation on cellular adhesion molecule expression and release of chemokines responsible for inflammatory cell recruitment in rats undergoing a total gastrectomy. Normal rats with internal jugular catheters were assigned to one control group and two experimental groups and received total parenteral nutrition (TPN). A total gastrectomy was performed in the experimental groups, whereas the control group received a sham operation (Sham). The TPN solutions were isonitrogenous and identical in nutrient composition except that the Sham group and one of the experimental group received conventional (Conv) TPN solution, whereas the other experimental group received 25% of the amino acid nitrogen as Gln. Half of the rats in each group were killed 1 or 3 d after surgery or the Sham to examine their immune response. The results showed that the surgery produced higher polymorphonuclear leucocyte CD11b/CD18 expressions, and Gln supplementation lowered CD11b/CD18 expressions compared with the Conv group post-operatively. The levels of monocyte chemotactic protein-1 and macrophage inflammatory protein-2 in peritoneal lavage fluid were higher in the Gln group than those in the Conv group 1 d post-operatively; these chemotactic proteins had returned to the levels comparable with those in the Sham group on post-operative day 3. These results suggest that Gln supplementation attenuated polymorphonuclear leucocyte integrin expression. In addition, Gln-enriched parenteral nutrition induced an earlier more intensive and rapid immune response to injury than the Conv parenteral nutrition after a total gastrectomy.

Gastrojejunocolic fistula after gastrojejunostomy: a case series.

INTRODUCTION: Gastrojejunocolic (GJC) fistulae represent a significant post-surgical cause of morbidity and mortality. GJC fistulae represent rare post-surgical complications, and most are associated with gastric surgery. In the past, this complication has been under-recognized because a fistula may form years after surgery. CASE PRESENTATION: We describe two cases of gastrojejunocolic fistula in men aged 67 and 60 who both initially presented with watery diarrhea and weight loss. Upper GI studies with small bowel follow-through or barium contrast enema studies allowed a conclusive diagnosis to be made. Both patients underwent one-stage en bloc resection, and their postoperative course was uneventful. CONCLUSION: With surgery, this condition is entirely correctable. Pre-operative nutritional status should be evaluated in patients undergoing corrective surgery, and total parenteral nutrition plays a major role in the provision of bowel rest to allow recovery in malnourished patients.

Effects of omega-3 fatty acids on leukocyte Th1/Th2 cytokine and integrin expression in rats with gut-derived sepsis.

OBJECTIVES: This study examined the effect of fish oil (FO)-enriched diets before and/or omega-3 fatty acid-containing total parenteral nutrition (TPN) after sepsis on the distribution of the T-lymphocyte subpopulation, intracellular cytokine, and intestinal immunity in rats with gut-derived sepsis. METHODS: Rats were assigned to a control or one of four experimental groups. The control group and groups 1 and 2 were fed a semipurified diet, and groups 3 and 4 received FO instead of 20% soybean oil. After feeding the diets for 10 d, sepsis was induced by cecal ligation and puncture (CLP) in the experimental groups, whereas a sham operation was performed in the control group. TPN was maintained for 3 d after the CLP or sham operation. The control group and groups 1 and 3 were infused with conventional TPN, whereas the TPN solution used for groups 2 and 4 were supplemented with FO. All rats were sacrificed 3 d after the operation to examine their immune responses. RESULTS: Plasma and intestinal immunoglobin A levels were higher in the FO-supplemented groups than in the control group and group 1. Lymphocyte interferon-gamma expression in groups 3 and 4 was significantly lower, whereas interleukin-4 expression was higher than those of the control group and groups 1 and 2. The splenocyte CD4 percentage in groups 3 and 4 and the CD4/CD8 ratio in group 4 were significantly higher than those in group 1. CONCLUSION: These findings suggest that FO administration before and/or after CLP are not immunosuppressive. FO-enriched diets before or before and after CLP resulted in a T-helper type 2 response and enhanced immunoglobulin A secretion. In addition, the splenocyte CD4 levels and CD4/CD8 ratio were maintained in rats with gut-derived sepsis.

Dietary glutamine supplementation reduces cellular adhesion molecule expression and tissue myeloperoxidase activity in mice with gut-derived sepsis.

OBJECTIVES: This study investigated the effects of glutamine (Gln) on plasma intracellular adhesion molecule-1 levels and leukocyte integrin (CD11a/CD18 and CD11b/CD18) expressions in gut-derived sepsis. Myeloperoxidase (MPO) activities in organs were also analyzed to identify the extent of tissue injury resulting from neutrophil infiltration. METHODS: Mice were randomly assigned to a normal group (NC), a control group, or a Gln group. The NC group was fed standard chow diet; the control group was fed a common semipurified diet; and the Gln group received a diet in which part of the casein was replaced by Gln, which provided 25% of total amino acid nitrogen. After 3 wk, sepsis was induced by cecal ligation and puncture (CLP) in the control and Gln groups. Mice in the experimental groups were killed at 0, 6, 12, and 24 h after CLP. Mice in the NC group were killed when CLP was performed. Blood and organ samples were collected for further analysis. RESULTS: Plasma intracellular adhesion molecule-1 levels were significantly lower in the Gln group than in the control group at 6, 12, and 24 h after CLP. Expressions of lymphocyte CD11a/CD18 were significantly higher, whereas polymorphonuclear lymphocyte expressions of CD11b/CD18 were lower in the Gln group than in the corresponding control group at 6 and 12 h after CLP. In comparisons of MPO activities in various organs, the Gln group had lower MPO activities at 6 and 12 h in the lung, at 6, 12, and 24 h in the liver, at 12 and 24 h in the kidneys, and at 12 h in the intestine than those in the control group. CONCLUSIONS: Results of this study demonstrate that a Gln-supplemented enteral diet increased lymphocyte CD11a/CD18 expressions, whereas neutrophil CD11b/CD18 expressions, circulating intracellular adhesion molecule-1 levels, and MPO activities in various organs decreased with gut-derived sepsis. These findings suggest that, under septic conditions, Gln administration may enhance lymphocyte function, attenuate interactions between polymorphonuclear lymphocytes and endothelium, and thus may decrease neutrophil infiltration into tissues.

Parenteral N-3 fatty acids modulate inflammatory and immune response in rats undergoing total gastrectomy.

This study investigated the effect of n-3 fatty acid (FA)-containing parenteral nutrition on the circulatory lymphocyte subpopulation, intracellular cytokine and leukocyte adhesion molecule expression, and phagocytic activity in rats undergoing total gastrectomy. Normal rats with internal jugular catheters were assigned to normal control (NC) and two experimental groups and received total parenteral nutrition (TPN). At the same time, a total gastrectomy was performed in the experimental groups, whereas the NC group underwent a sham operation. The TPN solutions were isonitrogenous and identical in nutrient compositions except for differences in fat emulsion contents. The NC and one of the experimental groups received a soybean oil emulsion (SO), and the other experimental group received 50% soybean oil and 50% fish oil emulsion (FO). Half of the rats in each respective group were sacrificed 1 or 3 days after surgery or the sham operation to examine their immune response. The results showed that the FO group had a higher CD4 proportion and CD4/CD8 ratio than those of the SO and NC groups postoperatively. The phagocytic activity of peritoneal macrophages was higher in the FO group than in the NC group, but no difference was found between the SO and NC groups 3 days after surgery. The intracellular interferon (IFN)-gamma distribution in the FO group was higher than that of the SO group on postoperative days. Leukocyte adhesion molecule expressions and peritoneal monocyte chemotactic protein-1 levels were lower in the FO group than in the SO group on postoperative day 3. These results suggest that parenterally infused FO did not result in immunosuppression. In addition, FO administration promotes lymphocyte Th1 cytokine production, enhances peritoneal macrophage phagocytic activity, and reduces leukocyte adhesion molecule expression in rats with total gastrectomy.

Glutamine-supplemented total parenteral nutrition attenuates plasma interleukin-6 in surgical patients with lower disease severity.

AIM: Previous reports have shown that decrease in plasma glutamine (Gln) level following major surgery may contribute to the state of immunosuppression. Gln supplementation improves the depletion of body Gln pool, and may have indirect effect on reducing proinflammatory mediator release. This study evaluated whether the effect of Gln dipeptide-enriched total parenteral nutrition (TPN) on postoperative cytokine alteration depended on the disease severity of surgical patients. METHODS: Forty-eight patients with major abdominal surgery were allocated to two groups to receive isonitrogenous (0.228 g nitrogen/kg per d) and isocaloric (30 kcal/kg per d) TPN for 6 d. Control group (Conv) using conventional TPN solution received 1.5 g amino acids/kg per day, whereas the test group received 0.972 g amino acids/kg per day and 0.417 g L-alanyl-L-glutamine (Ala-Gln)/kg per day. Blood samples were collected on d 1 and d 6 postoperatively for plasma interleukin (IL)-2, IL-6, IL-8, and interferon (IFN)-gamma analysis. RESULTS: Plasma IL-2 and IFN-gamma were not detectable. IL-6 concentrations were significantly lower on the 6(th) postoperative day in the Ala-Gln group than those in the Conv group in patients with APACHE II <=6, whereas no difference was noted in patients with APACHE II >6. There was no difference in IL-8 levels between the two groups. No difference in cumulative nitrogen balance was observed on d 2-5 after the operation between the two groups (Ala-Gln -3.2+/-1.6 g vs Conv -6.5+/-2.7 g). A significant inverse correlation was noted between plasma IL-6 levels and cumulative nitrogen balance postoperatively in the Ala-Gln group, whereas no such correlation was observed in the Conv group. CONCLUSION: TPN supplemented with Gln dipeptide had no effect on plasma IL-8 levels after surgery. However, Gln supplementation had a beneficial effect on decreasing systemic IL-6 production after surgery in patients with low admission illness severity, and lower plasma IL-6 may improve nitrogen balance in patients with abdominal surgery when Gln was administered.

Effects of glutamine supplementation on splenocyte cytokine mRNA expression in rats with septic peritonitis.

AIM: To investigate the effects of glutamine (GLN)-enriched diets before and GLN-containing total parenteral nutrition (TPN) after sepsis or both on the secretion of cytokines and their mRNA expression levels in splenocytes of rats with septic peritonitis. METHODS: Rats were assigned to a control group and 4 experimental groups. The control group and experimental groups 1 and 2 were fed a semipurified diet, while experimental groups 3 and 4 had part of the casein replaced by GLN which provided 25% of the total nitrogen. After rats were fed with these diets for 10 d, sepsis was induced by cecal ligation and puncture (CLP), whereas the control group underwent a sham operation, at the same time, an internal jugular vein was cannulated. All rats were maintained on TPN for 3 d. The control group and experimental groups 1 and 3 were infused with conventional TPN, while the TPN in experimental groups 2 and 4 was supplemented with GLN, providing 25% of the total nitrogen in the TPN solution. All rats were kiued 3 d after sham operation or CLP to examine their splenocyte subpopulation distribution and cytokine expression levels. RESULTS: Most cytokines could not be detected in plasma except for IL-10. No difference in plasma IL-10 was observed among the 5 groups. The IL-2, IL-4, IL-10, and TNF-alpha mRNA expression levels in splenocytes were significantly higher in experimental groups 2 and 4 than in the control group and group 1. The mRNA expression of IFN-gamma was significantly higher in the GLN-supplemented groups than in the control group and experimental group 1. The proportion of CD45Ra+ was increased, while those of CD3+ and CD4+ were decreased in experimental group 1 after CLP was performed. There were no differences in spleen CD3+ lymphocyte distributions between the control and GLN-supplemented groups. CONCLUSION: GLN supplementation can maintain T-lymphocyte populations in the spleen and significantly enhance the mRNA expression levels of Th1 and Th2 cytokines and TNF-alpha in the spleen of rats with septic peritonitis.

Glutamine supplementation enhances mucosal immunity in rats with Gut-Derived sepsis.

OBJECTIVE: Supplemental glutamine (Gln) has been demonstrated to improve the immunologic response and reduce mortality in rodents with sepsis. However, the effects of Gln on gut-associated lymphoid tissue function after infection and sepsis are not clear. We investigated the effects of Gln-supplemented diets before sepsis, Gln-enriched total parenteral nutrition (TPN) after sepsis, or both on the intestinal immunity in rats with gut-derived sepsis. METHODS: Male Wistar rats were assigned to control and four experimental groups. The control and experimental groups 1 and 2 were fed a semi-purified diet; in experimental groups 3 and 4, part of the casein in the diets was replaced with Gln. After feeding rats the respective diets for 10 d, sepsis was induced by cecal ligation and puncture (CLP) in the experimental groups, whereas the control group underwent a sham operation; at the same time, the internal jugular vein of all rats was cannulated. All rats were maintained on TPN for 3 d. The control group and groups 1 and 3 were infused with conventional TPN, and groups 2 and 4 were given a TPN solution supplemented with Gln, which provided 25% of total amino acid nitrogen. All rats were killed 3 d after the sham operation or CLP. Intestinal immunoglobin A levels, total lymphocyte yields, and lymphocyte subpopulations in Peyer's patches were analyzed. RESULTS: Total Peyer's patch lymphocyte numbers were significantly higher in the Gln-supplemented groups than in the control group. Distributions of CD3+ and CD4+ in group 1 were significantly lower than those in the control group, whereas no differences were observed among the control and Gln-supplemented groups. Plasma immunoglobulin A levels were higher in the Gln-supplemented groups than the control group and group 1. Intestinal immunoglobulin A levels were significantly higher in groups 2 and 4 than in the control group and group 1. CONCLUSIONS: Preventive use of a Gln-supplemented enteral diet before CLP or intravenous Gln supplementation after CLP have similar effects in promoting proliferation of total lymphocyte in gut-associated lymphoid tissue, enhancing IgA secretion, and maintaining T-lymphocyte populations in Peyer's patches. Gln administered before and after CLP did not seem to have a synergistic effect on enhancing mucosal immunity in rats with gut-derived sepsis.

Effects of glutamine supplementation on innate immune response in rats with gut-derived sepsis.

The present study examined the effect of glutamine (Gln)-enriched diets before sepsis or Gln-containing total parenteral nutrition (TPN) after sepsis, or both, on the phagocytic activity and blood lymphocyte subpopulation in rats with gut-derived sepsis. Rats were assigned to a control group or one of four experimental groups. The control group and groups 1 and 2 were fed a semipurified diet; groups 3 and 4 had part of casein replaced by Gln. After feeding the diets for 10 d, sepsis was induced by caecal ligation and puncture (CLP); TPN was maintained for 3 d after CLP. The control group and groups 1 and 3 were infused with conventional TPN and groups 2 and 4 were supplemented with Gln in the TPN solution. All rats were killed 3 d after CLP or sham operation to examine their immune responses. The results showed that compared with the control group, the phagocytic activities of peritoneal macrophages were enhanced in groups 3 and 4, but not in groups 1 and 2. The proportion of CD3+ cells in group 1 was significantly lower (P<0.05) than that of the control group, whereas no differences were observed among the control and Gln-supplemented groups. The CD4+ cell proportion was significantly lower (P<0.05) in group 1 compared with the control group and groups 3 and 4. These findings suggest that Gln-enriched diets before CLP significantly enhanced peritoneal macrophage phagocytic activity, preserved CD4+ cells and maintained blood total T lymphocytes in gut-derived sepsis. However, parenteral Gln administration after caecal ligation and puncture had no favourable effects on modulating immune response in septic rats.

Effects of dietary glutamine on antioxidant enzyme activity and immune response in burned mice.

OBJECTIVES: We investigated the effect of dietary glutamine (Gln) on specific antibody production and antioxidant enzyme activities in burned mice vaccinated with detoxified Pseudomonas exotoxin A linked with the outer membrane proteins I and F (PEIF). We also evaluated the survival rate of vaccinated and non-vaccinated burned mice infected with Pseudomonas aeruginosa. METHODS: There were three consecutive experiments. In experiment 1, 30 BALB/c mice were assigned to one of two groups. The control group was fed casein as the protein source; the Gln group received 4% Gln (w/w) to replace part of the casein. Mice were immunized twice with PEIF, and the production of specific antibodies against PEIF was measured every week. Eight weeks after immunization, all mice received a 30% body surface area burn injury. Mice were killed 24 h after the burn. The antioxidant enzyme activities and lipid peroxides in the tissues and specific antibody production were analyzed. In experiment 2, 12 mice were assigned to a control or a Gln group and fed with one the experimental diets for 4 wk. Then burn injury was induced, and mice were killed 24 h later. In vitro, splenocytes were cultured, and interleukin (IL)-4 and IL-10 were measured after mitogen stimulation. In experiment 3, survival rates of vaccinated and non-vaccinated burned mice complicated with P. aeruginosa infection were evaluated. The survival rate was observed for 8 d after the burn. RESULTS: Antioxidant enzyme activities and lipid peroxides in tissues tended to be lower in the Gln group than in the control group after the burn. Specific antibody production against P. aeruginosa increased significantly in the Gln group at 4 and 7 wk after immunization and at 24 h after the burn. IL-4 concentrations in mitogen-stimulated splenocytes were significantly higher in the Gln group than in the control group. Survival rates of non-vaccinated burned mice in the Gln group were significantly higher than those in the control group, whereas there was no difference in the survival of vaccinated burned mice after bacterial infection. CONCLUSIONS: These results suggested that vaccinated mice receiving a Gln-enriched diet may have enhanced humoral immunity and attenuated oxidative stress induced by burn injury. Also, Gln supplementation improved the survival of burned mice complicated with P. aeruginosa infection.

Effects of arginine-enriched total parenteral nutrition on inflammatory-related mediator and T-cell population in septic rats.

OBJECTIVES: Previous reports have shown that oral arginine (Arg) has immune-enhancing properties in injury. However, the effects of parenterally infused Arg on sepsis are not well understood. We used a septic rat model to study Arg infusion in inflammatory-related cytokines and blood T lymphocyte population in vivo. METHODS: Rats with internal jugular catheters were assigned to one of two groups. Both groups received isonitrogenous total parenteral nutrition (TPN) supplemented with 270 mg of nitrogen per kilogram per day as Arg or glycine (Gly). TPN provided 270 kcal/kg of body weight, and the kilocalorie:nitrogen ratio was 143:1. TPN was maintained for 5 d plus 2, 4, or 6 h or 6 d, according to the scheduled deaths of the rats. On day 5, sepsis was induced by cecal ligation and puncture (CLP). After CLP for 2, 4, 6, and 24 h, rats were killed. RESULTS: The results showed that interleukin-1beta and tumor necrosis factor-alpha concentrations in peritoneal lavage fluid at 6 h and interleukin-6 levels at 24 h after CLP in the Gly group were significantly higher than those in the Arg group. The T-lymphocyte population in blood showed that CD8(+) suppressor T-cell number was significantly higher in the Gly group than in the Arg group at 6 h after CLP. The blood CD4(+):CD8(+) ratio was significantly higher in the Arg group than in the Gly group at 24 h after CLP. A negative nitrogen balance was observed in the Arg and Gly groups after CLP; there was no significant difference in nitrogen balance between the septic groups. No difference in survival rate at 24 h after CLP was observed between the groups. CONCLUSIONS: The results showed that, compared with the Gly group, TPN preinfused with Arg reduces the production of inflammatory mediators at the site of injury and that cellular immunity is enhanced at 24 h after CLP. Parenterally administered Arg had no beneficial effect in preventing nitrogen loss and improving survival in septic rats. Whether Gly has specific effects that reduce the effects of Arg require further investigation.