Effects Of Glutamine Supplementation Research Articles

Effect of glutamine supplementation on neutrophil function in male judoists

Glutamine is an important amino acid for immune function. Though high intensity and prolonged exercise decreases plasma glutamine concentration and causes immune suppression, the relationship between neutrophil functions and glutamine has not yet been found. The purpose of this study was to investigate the impacts of glutamine supplementation on neutrophil function. Twenty-six male university judoists were recruited. Subjects were classified into glutamine and control groups. The glutamine group ingested 3000 mg of glutamine per day and the control group ingested placebo for 2 weeks. Examinations were performed at the start of preunified loading exercise (pre-ULE), then 1 and 2 weeks after ULE (post-ULE). Reactive oxygen species (ROS) production, phagocytic activity, serum opsonic activity and serum myogenic enzymes were measured. Differences between the levels obtained in pre-ULE and post-ULE for the two groups were compared. In the glutamine group, ROS production activity increased 1 week after ULE, whereas it was not observed in the control group (P < 0.001). Though myogenic enzymes increased significantly after ULE (P < 0.001), the glutamine group remained unchanged by supplementation during ULE. Glutamine supplementation has prevented excessive muscle damage and suppression of neutrophil function, especially in ROS production activity, even during an intensive training period.

Effects of glutamine supplementation on muscle function and stress responses in a mouse model of spinal cord injury

Spinal cord injury (SCI) results in loss of muscle function due to rapid breakdown of contractile proteins. Glutamine supplementation improves clinical outcomes, but its effects on muscle function after SCI are unknown. The benefits of glutamine in non-skeletal muscle tissues involve elevated heat shock protein (Hsp)70 and Hsp25, but the muscle response may differ because it is the largest contributor to plasma glutamine. We tested the hypothesis that glutamine preserves muscle function after SCI and that this is associated with increased heat shock protein and reduced inflammatory factors, interleukin-6 (IL-6) and tumour necrosis factor-α (TNFα). Changes in plantarflexor force, fatigability and total myofibrillar, Hsp70, Hsp25, IL-6 and TNFα muscle protein levels were measured 7 days after sham or spinal cord transection surgery in mice receiving daily placebo or glutamine. Compared with placebo, after SCI glutamine significantly attenuated the reductions in maximal isometric force (0.22 ± 0.01 versus 0.31 ± 0.03 N, respectively) and fatigue resistance (34 ± 4 versus 59 ± 4% of initial force, respectively). Glutamine significantly ameliorated the loss of myofibrillar protein with spinal cord transection. Spinal cord transection was associated with decreased Hsp70 and Hsp25 with glutamine only (45 ± 3 and 44 ± 5% of placebo, respectively). Glutamine significantly reduced spinal cord transection-associated increases in IL-6 and TNFα compared with placebo (38 ± 6 and 37 ± 8% of placebo, respectively). Functionally, early reductions in contractile protein, force and fatigue resistance after SCI were reversed with glutamine. Spinal cord transection-associated reductions in Hsp70, Hsp25, IL-6 and TNFα with glutamine versus placebo suggest lower stress in the muscle, possibly related to a reduced need to produce glutamine. These findings support glutamine as a therapeutic intervention to accelerate recovery of muscle function after SCI.

Suplementação de glutamina em dietas elaboradas com ingredientes de origem vegetal e animal para pintos de corte

Foi avaliado o efeito da suplementação da glutamina em dietas contendo ingredientes de origem animal sobre o desempenho e a integridade intestinal de pintos de corte, criados até 21 dias de idade. Os tratamentos constituíram-se de combinações entre tipos de dieta, com ingredientes de origem vegetal ou vegetal+animal e suplementação de glutamina (0,0; 0,5; 1,0 e 2,0%). O delineamento foi em blocos ao acaso em arranjo fatorial 2x4, tipos de ração x percentagem de glutamina, com cinco repetições e 12 pintos por unidade experimental. Não houve efeito da interação tipo de dieta versus suplementação de glutamina sobre o desempenho, e os tratamentos não influenciaram o desempenho de pintos de corte. Houve efeito quadrático da suplementação de glutamina sobre o coeficiente de digestibilidade da proteína bruta. A suplementação com glutamina aumentou altura de vilos e profundidade de cripta no duodeno. A utilização de produtos de origem animal em dietas para pintos na fase inicial não prejudica o desempenho, e a inclusão de glutamina melhora a integridade intestinal.

Effects of glutamine supplementation on the immune status in weaning piglets with intrauterine growth retardation

Neonates with intrauterine growth retardation (IUGR) often suffer from impaired cellular immunity, and weaning may further aggravate adverse effects of IUGR on development and function of the immune system. In this study, we investigated effects of glutamine supplementation on immune status in the intestines of weaning pigs with IUGR, focusing on molecular mechanisms underlying altered immune response. Piglets with IUGR were weaned at 21 days of age and received orally 1.22 g alanine or 1 g glutamine per kg body weight every 12 h. Weight gain and intestinal weight of weaning piglets were increased by glutamine supplementation. Levels of serum IgG in piglets supplemented with glutamine were increased compared with Control piglets. The production of IL-1 and IL-8 in the serum and jejunum was decreased by glutamine supplementation, whereas the levels of IL-4 in the serum and the concentrations of IL-4 and IL-10 in the jejunum were increased. The expression of heat shock protein 70 (Hsp70) in the jejunum was increased by glutamine supplementation, but the degradation of inhibitor κB and the activity of nuclear factor-κB (NF-κB) were decreased. In conclusion, glutamine supplementation enhanced immune response in weaning piglets with IUGR. The effects of glutamine in IUGR are associated with increased Hsp70 expression and suppression of NF-κB activation.

Effects of glutamine supplementation on muscle function in a mouse model of spinal cord injury

Spinal cord injury (SCI) results in loss of muscle function due to rapid breakdown of contractile proteins. Glutamine (GLN) supplementation improves clinical outcomes, but its effects on muscle function after SCI are unknown. Improvements with GLN in non‐skeletal muscle tissues have been related to elevated heat shock protein 70 (Hsp70) and Hsp25, but the muscle response may differ since it is the largest contributor to plasma GLN. We tested the hypothesis that GLN preserves muscle function after SCI and this is associated with increased Hsp levels. Changes in plantarflexor mass, force, fatigability, and Hsp70 and 25 protein were measured 7 d after sham or spinal cord transection (ST) surgery in mice receiving daily placebo (PL) or GLN. ST reduced muscle mass with PL or GLN (p&lt;0.05). Maximal isometric force relative to body mass was not different among groups, but GLN prevented greater fatigability seen with ST + PL (59±4 vs. 34±4% of initial force after 10 contractions, respectively, p&lt;0.05). ST was associated with decreased Hsp70 and 25 with GLN only (49±3 and 44±5% of PL, respectively, p&lt;0.05). Functionally, early increases in fatigability after SCI were reversed with GLN. ST‐associated reductions in Hsp70 and 25 with GLN vs. PL suggest lower stress in the muscle, possibly related to a reduced need to produce GLN. These findings support GLN as a therapeutic intervention to accelerate recovery of muscle function after SCI.

The effects of glutamine supplementation on performance and hormonal responses in non-athlete male students during eight week resistance training

Hakimi M, Mohamadi MA, Ghaderi Z. The effects of glutamine supplementation on performance and hormonal responses in non-athlete male students during eight week resistance training. J. Hum. Sport Exerc. Vol. 7, No. 4, pp.770-782, 2012. The aim of this study was to determine the effects of glutamine supplementation on performance, and hormonal changes during an 8-week resistance training program in non athlete male students. Thirty healthy non athlete male (age 21.25 ± 1.6 years, height 173.2 ± 3.2 cm, body mass 72.8 ± 2.8 kg, VO2max 43.48± 2.38 ml·kg -1 ·min -1 ) were randomly divided into a glutamine supplementation (GL) group (n=15), and a placebo (PL) group (n=15). Each group was given either glutamine or a placebo in a double blind manner to be taken orally for eight weeks (0.35 g/kg/day). GL and PL groups performed the same weight training program 3 days, each week for 8 weeks. The training consisted of 3 sets of 8 repetitions, and the initial weight was 80% of the pre-1RM. Subjects were tested for performance and blood hormone concentrations before and after the 8-week period. Both groups increased their performance however the GL group showed significantly greater increases in upper and lower body strength, explosive muscular power, blood testosterone, GH and IGF-1 when compared to the PL group; however, cortisol concentrations were significantly more reduced in GL group when compared to the PL group. It can, therefore, be concluded that within 8 weeks glutamine supplementation during resistance training was found to increase performance (explosive muscular power, muscle strength) and improved

Effects of glutamine supplementation on oxidative stress-related gene expression and antioxidant properties in rats with streptozotocin-induced type 2 diabetes

There are close links among hyperglycaemia, oxidative stress and diabetic complications. Glutamine (GLN) is an amino acid with immunomodulatory properties. The present study investigated the effect of dietary GLN on oxidative stress-relative gene expressions and tissue oxidative damage in diabetes. There were one normal control (NC) and two diabetic groups in the present study. Diabetes was induced by an intraperitoneal injection of nicotinamide followed by streptozotocin (STZ). Rats in the NC group were fed a regular chow diet. In the two diabetic groups, one group (diabetes mellitus, DM) was fed a common semi-purified diet while the other group received a diet in which part of the casein was replaced by GLN (DM-GLN). GLN provided 25% of total amino acid N. The experimental groups were fed the respective diets for 8 weeks, and then the rats were killed for further analysis. The results showed that blood thioredoxin-interacting protein (Txnip) mRNA expression in the diabetic groups was higher than that in the NC group. Compared with the DM group, the DM-GLN group had lower glutamine fructose-6-phosphate transaminase 1, a receptor of advanced glycation end products, and Txnip gene expressions in blood mononuclear cells. The total antioxidant capacity was lower and antioxidant enzyme activities were altered by the diabetic condition. GLN supplementation increased antioxidant capacity and normalised antioxidant enzyme activities. Also, the renal nitrotyrosine level and Txnip mRNA expression were lower when GLN was administered. These results suggest that dietary GLN supplementation decreases oxidative stress-related gene expression, increases the antioxidant potential and may consequently attenuate renal oxidative damage in rats with STZ-induced diabetes.

Effects of glutamine supplementation on kidney of diabetic rat

Glutamine is the most important donor of NH(3) in kidney playing an important role in acid-base buffering system. Besides this effect, glutamine presents many other relevant functions in the whole body, such as a precursor of arginine in adult and neonates. In addition to these effects, some studies have shown that glutamine can potentiate renal disease. In the present study, the effect of short-term treatment (15 days) with glutamine on control and diabetic rats was investigated. Using biochemical, histological and molecular biology analysis from control and diabetic rats we verified that glutamine supplementation increase in pro-inflammatory interleukins (IL)-1beta and IL-6 content in renal cortex and induce alteration in glomerular characteristics. This study showed that short-term treatment with glutamine in association with increased glucose levels could cause important alterations in glomerular morphology that may result in fast progression of kidney failure.

The Effects of Parenteral Glutamine Supplementation on Immunological Modulation in Extensive Burn Injury Patients

Background: Glutamine is an important energy source for immune cells. Several clinical trials have supported that glutamine supplementation in severely burned patients can maintain the immunologic function and improve the outcome. Aim and Objectives: The aim of this clinical study was to observe the effects of glutamine supplementation on immunologic modulation in extensive burn injury patients from the alternations of T cell and B cell lymphocytes counts and their differentiated ratios. Materials and methods: From July 2006 to September 2007, seven patients with extensive burn (total burn surface area 65.57±13.59%, range: 50%-90%) were enrolled in this prospective clinical trial. Patients received parenteral glutamine in doses of 20 g/day for 7 days. Alterations in immunologic function indices including T cell, B cell, CD4+ cell counts (μL^(-1)), differentiated count ratios (%), and the changes of CD4/CD8 ratio were determined on the 1st day and the 8th day from the initiation of glutamine treatment. The pre-treatment data on the 1st day was then compared with the post-treatment data on the 8th day. Results: There were no significant changes between the T cell (721±571 and 361±124 μL^(-1), P=0.149) and B cells counts (311±210 and 190±155 μL^(-1), P=0.267) after glutamine therapy. The T cell differentiated count ratio after glutamine supplementation was significantly higher than before treatment (59.77±16.72% and 71.27±10.94%, P=0.009). We especially observed a greater increase in patients with lower initial T cell differentiated count ratio. However, there was a decrease in B cell differentiated count ratios (29.24±12.96% and 19.93±12.08%, P=0.154). Although the CD4+ cell counts did not increase significantly after parenteral glutamine supplementation, (357±275 and 252±110 μL^(-1), P=0.437), we found the CD4+ differentiated count ratio increased significantly after glutamine therapy (30.93±7.99% and 43.96±3.21%, P=0.01). Conclusion: Parenteral glutamine supplementation in extensive burn patients increases the Tlymphocyte and CD4+ cell differentiated count ratios, as well as modulate the cellular immunologic function rather than the humoral response. The possible process is first to stimulate the helper T (CD4+) cells, which play the most important role in initiation of immunologic function and regulation.

Effects of Glutamine Supplementation on Patients Undergoing Abdominal Surgery

To evaluate the effects of supplementation of glutamine (GLN) on maintaining glutathione (GSH) level, immune system function, liver function, and clinical outcome of patients receiving abdominal operation. Forty patients undergoing elective abdominal surgical treatment were randomly divided into 2 groups: study group (n = 20) and control group (n = 20). All patients received total parenteral nutrition (TPN) for up to 7 days during perioperative period. The study group received TPN supplemented with GLN dipeptide while the control group received TPN without GLN dipeptide. Patients in both groups received equivalent nitrogen and caloric intake. Blood sample was taken on preoperative day, and the 1st, 3rd, 6th postoperative day to measure GSH level, immune indexes, and liver function indexes. The decrease of GSH level in plasma and red blood cell (RBC) in study group was less than that in control group during postoperative period. Ratio of GSH/glutathione disulfide (GSSG) in plasma in study group was higher than that in control group on the 3rd postoperative day (52.53 +/- 11.46 vs. 31.43 +/- 7.27, P = 0.001). Albumin level in study group was higher than that in control group on the 3rd postoperative day (37.7 +/- 3.8 g/L vs. 33.8 +/- 4.2 g/L, P = 0.02). There was no significant difference in the levels of immunoglobin (IgG, IgM, IgA) or T lymphocyte subgroup (CD4, CD8, CD4/CD8) in both groups during postoperative period. There was one case with infectious complication in control group, while none in study group. A trend of shortened hospital stay was observed in study group compared with control group (22.3 +/- 2.1 d vs. 24.9 +/- 1.7 d, P = 0.32). Supplementation of GLN-enriched TPN has beneficial effects on maintaining GSH levels in plasma and RBC, sustaining GSH/GSSG ratio and albumin level, and keeping antioxidant abilities during postoperative period in patients with abdominal operation, with the trends of decreasing incidence of infectious complication and shortening hospital stay.

No effect of glutamine supplementation and hyperoxia on oxidative metabolism and performance during high-intensity exercise

Glutamine enhances the exercise-induced expansion of the tricarboxylic acid intermediate pool. The aim of the present study was to determine whether oral glutamine, alone or in combination with hyperoxia, influenced oxidative metabolism and cycle time-trial performance. Eight participants consumed either placebo or 0.125 g · kg body mass−1 of glutamine in 5 ml · kg body mass−1 placebo 1 h before exercise in normoxic (control and glutamine respectively) or hyperoxic (FiO2 = 50%; hyperoxia and hyperoxia + glutamine respectively) conditions. Participants then cycled for 6 min at 70% maximal oxygen uptake ([Vdot]O2max) immediately before completing a brief high-intensity time-trial (∼4 min) during which a pre-determined volume of work was completed as fast as possible. The increment in pulmonary oxygen uptake during the performance test (Δ[Vdot]O2max, P = 0.02) and exercise performance (control: 243 s, s x = 7; glutamine: 242 s, s x = 3; hyperoxia: 231 s, s x = 3; hyperoxia + glutamine: 228 s, s x = 5; P < 0.01) were significantly improved in hyperoxic conditions. There was some evidence that glutamine ingestion increased Δ[Vdot]O2max in normoxia, but not hyperoxia (interaction drink/FiO2, P = 0.04), but there was no main effect or impact on performance. Overall, the data show no effect of glutamine ingestion either alone or in combination with hyperoxia, and thus no limiting effect of the tricarboxylic acid intermediate pool size, on oxidative metabolism and performance during maximal exercise.

The effect of glutamine supplementation on hematopoietic stem cell transplant outcome in children: A case–control study

HSCT associated morbidity and mortality is usually attributed to high-dose chemotherapy/radiotherapy regimens used for conditioning. Glutamine (Gln), a conditionally essential amino acid during severe catabolic states, has been shown to have favorable effects in patients with malignancies and in those undergoing HSCT. However, controversy exists regarding its routine use. Studies in children investigating gln supplementation are very limited. In the present study, including 21 gln-supplemented and 20 control pediatric patients, gln supplementation was shown to reduce the duration of fever and decrease the incidence of SOS during the HSCT course. In addition, a decrease in drug-related toxicity and a trend toward reduced incidence of severe mucositis were observed.

The effect of glutamine supplementation and physical exercise on neutrophil function

Glutamine is the most abundant free amino acid in the body. Its primary source is skeletal muscle, from where it is released into the bloodstream and transported to a variety of tissues. Several studies have shown that glutamine is important for rat and human neutrophil function and that these cells utilize glutamine at high rates. Physical exercise has also been shown to induce considerable changes in neutrophil metabolism and function. As neutrophils represent 50-60% of the total circulating leukocyte pool and play a key role in inflammation, both physical exercise and glutamine might be expected to regulate the inflammatory process. In this review, the changes in neutrophil function induced by physical exercise and glutamine supplementation are compared.

Effect of Glutamine Supplementation on Splanchnic Metabolism in Lactating Dairy Cows

The suggestion that glutamine (Gln) might become conditionally essential postpartum in dairy cows has been examined through increased postruminal supply of Gln. Net nutrient flux through the splanchnic tissues and mammary gland was measured in 7 multiparous Holstein cows receiving abomasal infusions of water or 300g/d of Gln for 21 d in a crossover design. Milk yield increased significantly (by 3%) in response to Gln supplementation, but the 2.4% increase in milk protein yield was not statistically significant. Glutamine treatment had no effect on portal or hepatic venous blood flows. Net portal appearance of Gln and Glu was increased by Gln supplementation, accounting for 83% of the infused dose with, therefore, only limited amounts available to provide additional energy to fuel metabolism of the portal-drained viscera. The extra net portal appearance of Gln was offset, however, by a corresponding increase in hepatic removal such that net Gln splanchnic release was not different between treatments. Nonetheless, the Gln treatment resulted in a 43% increase in plasma Gln concentration. Infusions of Gln did not affect splanchnic flux of other nonessential amino acids or of essential amino acids. Glutamine supplementation increased plasma urea-N concentration and tended to increase net hepatic urea flux, with a numerical increase in liver hepatic O2 consumption. There were no effects on glucose in terms of plasma concentration, net portal appearance, net liver release, or postliver supply, suggesting that Gln supplementation had no sparing effect on glucose metabolism. Furthermore, mammary uptake of glucose and amino acids, including Gln, was not affected by Gln supplementation. In conclusion, this study did not support the hypothesis that supplemental Gln would reduce glucose utilization across the gut or increase liver gluconeogenesis or mammary glutamine uptake to increase milk protein synthesis.

Does Glutamine Supplementation Decrease the Response of Muscle Glutamine Synthesis to Fasting in Muscle in Adult and Very Old Rats?

Glutamine synthetase (GS), a key enzyme in the production of glutamine, is preserved in rat skeletal muscle during aging but is increased with advanced age in vivo. The aim of this study was to determine whether glutamine supplementation affects up-regulation of GS by fasting in vivo in adult and very old female rats. Muscle GS activities were assessed in 5-day-fasted female Wistar adult (6 months) and very old (27 months) rats refed and supplemented with glutamine or other amino acids (alanine or glycine). Fed rats were used to investigate the possible effect of glutamine supplementation in the fed state. After 5 days' fasting, the up-regulated GS activity was decreased whatever the type of amino acid supplementation (glutamine, alanine, and glycine) in adults, whereas it was only decreased by glutamine supplementation in very old rats). In the fed state, no effect of glutamine supplementation was observed even if GS activity remained up-regulated whatever the age and the period of supplementation. These results confirm that glutamine has a specific role in very old rats. The up-regulated GS activity was decreased by an exogenous supply of glutamine only if intramuscular glutamine was depleted; this was confirmed by studies in the fed state. The up-regulated GS activity in both fed and fasted rats may be associated with increased glutamine requirements in the whole body.

Effects of glutamine supplementation on gut barrier, glutathione content and acute phase response in malnourished rats during inflammatory shock

To evaluate the effect of glutamine on intestinal mucosa integrity, glutathione stores and acute phase response in protein-depleted rats during an inflammatory shock. Plasma acute phase proteins (APP), jejunal APP mRNA levels, liver and jejunal glutathione concentrations were measured before and one, three and seven days after turpentine injection in 4 groups of control, protein-restricted, protein-restricted rats supplemented with glutamine or protein powder. Bacterial translocation in mesenteric lymph nodes and intestinal morphology were also assessed. Protein deprivation and turpentine injection significantly reduced jejunal villus height, and crypt depths. Mucosal glutathione concentration significantly decreased in protein-restricted rats. Before turpentine oil, glutamine supplementation restored villus heights and glutathione concentration (3.24 +/- 1.05 vs 1.72 +/- 0.46 mumol/g tissue, P<0.05) in the jejunum, whereas in the liver glutathione remained low. Glutamine markedly increased jejunal alpha1-acid glycoprotein mRNA level after turpentine oil but did not affect its plasma concentration. Bacterial translocation in protein-restricted rats was not prevented by glutamine or protein powder supplementation. Glutamine restored gut glutathione stores and villus heights in malnourished rats but had no preventive effect on bacterial translocation in our model.

Mountain bike racing - the influence of prior glycogen-inducing exercise and glutamine supplementation on selected stress and immune parameters

Objective. To investigate the effect of pre-exercise glutamine supplementation and the influence of a prior acute bout of glycogen-reducing exercise on the general stress and immune response to acute high-intensity cycling. Design. Randomised, double-blind, cross-over supplementation study. Setting and intervention. Subjects performed a series of 4 simulated mountain-bike races lasting ≈60 minutes each on separate days 1 week apart, with/ without prior glycogen- reducing exercise on a known outdoor course with/ without pre-exercise glutamine supplementation. Blood samples were collected pre- and immediately post-exercise after each race. Main outcome measures. Circulating concentrations of cortisol (COR) and dehydroepiandrosterone-sulphate (DHEAS) were assessed at all time points, as well as changes in white blood cell (WBC) subpopulation distribution. Results. COR was elevated in all groups post-exercise (p &lt; 0.0001), but neither glycogen reduction, nor glutamine supplementation had any effect. DHEAs increased post-exercise (p &lt; 0.05), with a greater relative increase in glutamine-supplemented subjects (p = 0.07). Total WBC and neutrophil counts in all groups were elevated after exercise (both p &lt; 0.0005). Glutamine supplementation had no effect on differential WBC counts or distribution, but total WBC (p = 0.06) and monocyte (p &lt; 0.05) counts showed greater increases after glycogen reduction. Gluta- mine supplementation was associated with greater postexercise decreases in CD4+ count (p = 0.07) and CD4+: CD8+ ratio (p = 0.01) after glycogen-reducing exercise. Conclusions. We conclude that pre-exercise glutamine supplementation may have an anticortisol effect by enhancing the DHEAS response to exercise stress. The suppressive effect of glutamine supplementation on CD4+: CD8+ ratio and its positive effect on monocyte count after repeated bouts of exercise warrants further investigation. South African Journal of Sports Medicine Vol. 18 (4) 2006: pp. 122-128

Effects of Glutamine on Blastocoele Formation and Hatching in Mouse Preimplantation Embryos

ABSTRACT The effects of glutamine supplementation on the blastocoele formation and hatching of mouse preimplantation embryos were investigated. When culturing the 1-cell or 2-cell stage embryos in glutamine-supplemented media, the incidence of development to each stage from the morula stage to the completely hatched blastocyst stage was higher than for culturing in media without glutamine supplementation. When culturing 4-cell stage, 8-cell stage or morula stage embryos in glutamine-supplemented media, percentage of development up to the expanded blastocyst stage was comparable to culturing in media without glutamine supplementation, but the hatching rate for the glutamine-supplemented media was higher or tended to be higher compared to culturing in media without glutamine supplementation. Further, culturing in glutamine-supplemented media from the early blastocyst stage, the blastocyst stage or the expanded blastocyst stage resulted in a higher hatching rate compared to culturing in media without glutami...

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

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. 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. 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. 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.

The effect of glutamine supplementation on the function of neutrophils from exercised rats

In a recent publication, we showed the protective effect of glutamine on neutrophil apoptosis induced by acute exercise. The purpose of the present study was to examine the effect of a single bout of intensive exercise on rat neutrophil function and the possible effect of glutamine supplementation. An aqueous solution of glutamine was given by gavage (1 g per kg b.w.), 1 h before the exercise session. The exercise was carried out on a treadmill for 1 h at 85% VO2máx.. Neutrophils were obtained by intraperitoneal lavage with PBS. The following parameters were evaluated: phagocytosis capacity, production of nitric oxide and reactive oxygen metabolites, expression of iNOS, and expression of NADPH-oxidase components (p22phox, p47phox and gp91phox). One hour of exercise at 85% VO2max. induced no change in the phagocytosis capacity and reactive oxygen species production but decreased nitric oxide production. When rats received oral glutamine supplementation, the phagocytosis capacity was significantly increased, the decrease in nitric oxide production induced by exercise was abolished and production of reactive oxygen species was raised. Glutamine supplementation presents a significant effect on neutrophil function including changes induced by exercise.