RESUMO
Dietary glutamine (Gln) supplementation improves intestinal function in several stressful conditions. Therefore, in the present study, the effects of dietary Gln supplementation on the core body temperature (T core), bacterial translocation (BT) and intestinal permeability of mice subjected to acute heat stress were evaluated. Male Swiss mice (4 weeks old) were implanted with an abdominal temperature sensor and randomly assigned to one of the following groups fed isoenergetic and isoproteic diets for 7 d before the experimental trials: group fed the standard AIN-93G diet and exposed to a high ambient temperature (39°C) for 2 h (H-NS); group fed the AIN-93G diet supplemented with l-Gln and exposed to a high temperature (H-Gln); group fed the standard AIN-93G diet and not exposed to a high temperature (control, C-NS). Mice were orally administered diethylenetriaminepentaacetic acid radiolabelled with technetium (99mTc) for the assessment of intestinal permeability or 99mTc-Escherichia coli for the assessment of BT. Heat exposure increased T core (approximately 41°C during the experimental trial), intestinal permeability and BT to the blood and liver (3 h after the experimental trial) in mice from the H-NS group relative to those from the C-NS group. Dietary Gln supplementation attenuated hyperthermia and prevented the increases in intestinal permeability and BT induced by heat exposure. No correlations were observed between the improvements in gastrointestinal function and the attenuation of hyperthermia by Gln. Our findings indicate that dietary Gln supplementation preserved the integrity of the intestinal barrier and reduced the severity of hyperthermia during heat exposure. The findings also indicate that these Gln-mediated effects occurred through independent mechanisms.
Assuntos
Translocação Bacteriana/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Suplementos Nutricionais , Febre/prevenção & controle , Glutamina/uso terapêutico , Temperatura Alta , Mucosa Intestinal/efeitos dos fármacos , Animais , Dieta , Escherichia coli , Glutamina/farmacologia , Golpe de Calor/prevenção & controle , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Fígado/microbiologia , Camundongos , PermeabilidadeRESUMO
Glutamine may be a precursor for NO synthesis, which may play a crucial role in bacterial translocation (BT). The goal of the present study was to investigate the potential effects of glutamine on BT and the immunological response in an experimental model of NO synthase inhibition by NG-nitro-L-arginine methyl ester (l-NAME). Mice were randomly assigned to four groups: sham; intestinal obstruction (IO); IO+500 mg/kg per d glutamine (GLN); IO+GLN plus 10 mg/kg per d l-NAME (GLN/LN). The groups were pretreated for 7 d. BT was induced by ileal ligation and was assessed 18 h later by measuring the radioactivity of 99mTc-Escherichia coli in the blood and organs. Mucosal damage was determined using a histological analysis. Intestinal permeability (IP) was assessed by measuring the levels of 99mTc-diethylenetriaminepentaacetic acid in the blood at 4, 8 and 18 h after surgery. IgA and cytokine concentrations were determined by ELISA in the intestinal fluid and plasma, respectively. BT was increased in the GLN/LN and IO groups than in the GLN and sham groups. IP and intestinal mucosa structure of the sham, GLN and GLN/LN groups were similar. The GLN group had the highest levels of interferon-γ, while IL-10 and secretory IgA levels were higher than those of the IO group but similar to those of the GLN/LN group. The present results suggest that effects of the glutamine pathway on BT were mediated by NO. The latter also interferes with the pro-inflammatory systemic immunological response. On the other hand, IP integrity preserved by the use of glutamine is independent of NO.
Assuntos
Translocação Bacteriana , Glutamina/metabolismo , Íleo/metabolismo , Mucosa Intestinal/metabolismo , Obstrução Intestinal , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico/metabolismo , Animais , Translocação Bacteriana/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Escherichia coli , Glutamina/farmacologia , Íleo/efeitos dos fármacos , Íleo/microbiologia , Íleo/patologia , Imunoglobulina A/metabolismo , Imunoglobulina A Secretora/metabolismo , Interferon gama/metabolismo , Interleucina-10/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Obstrução Intestinal/microbiologia , Obstrução Intestinal/patologia , Ligadura , Masculino , Camundongos , Camundongos Endogâmicos , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/imunologia , Ácido Pentético/sangue , Permeabilidade , Transdução de SinaisRESUMO
OBJECTIVE: To evaluate the effects of arginine on intestinal barrier integrity and bacterial translocation (BT) in mice undergoing intestinal obstruction. METHODS: Mice were divided into 3 groups, treated for 7 d before surgical intervention with isocaloric and isoprotein diets. The ARG group received a diet containing 2% arginine, the IO (intestinal obstruction) and Sham groups, standard chow diet. On the eighth day of treatment, all animals received diethylenetriamine pentaacetic acid (DTPA) solution labeled with 99mTechnetium (99mTc-DTPA) by gavage for intestinal permeability analysis. After 90 min, the animals were anesthetized and the terminal ileum ligated. The Sham group only underwent laparotomy. After 4, 8, and 18 h, blood was collected for radioactivity determination. Samples of ileum were collected 18 h after surgery for histological analysis. In another set of animals, BT was evaluated. After 7 d of treatment, all animals received 10(8) CFU/mL of 99mTc-E.coli by gavage; 90 min later they were submitted to the surgical procedure described above. BT was determined by the uptake of 99mTc-E.coli in blood, mesenteric lymph nodes, liver, spleen, and lungs, assessed 18 h after the surgery. RESULTS: The intestinal permeability and BT were higher in the IO group when compared with the Sham group (P < 0.05). Arginine supplementation reduced intestinal permeability and BT to physiologic levels. Histological analysis showed mucosal ileum preservation in animals treated with arginine. CONCLUSION: Arginine was able to preserve barrier integrity, thus reducing BT.
Assuntos
Arginina/farmacologia , Translocação Bacteriana/efeitos dos fármacos , Escherichia coli/fisiologia , Mucosa Intestinal/efeitos dos fármacos , Obstrução Intestinal , Animais , Arginina/administração & dosagem , Sangue/efeitos dos fármacos , Sangue/microbiologia , Dieta , Infecções por Escherichia coli/prevenção & controle , Íleo/efeitos dos fármacos , Íleo/microbiologia , Íleo/patologia , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Isótopos , Fígado/efeitos dos fármacos , Fígado/microbiologia , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Linfonodos/efeitos dos fármacos , Linfonodos/microbiologia , Camundongos , Ácido Pentético , Permeabilidade , Baço/efeitos dos fármacos , Baço/microbiologia , TecnécioRESUMO
The aim of this study was to investigate the effect of ingesting high-sucrose (HSD) and high-lipid diets (HLD) on the concentrations of plasma glucose and leptin in lean and overweight women. Twenty healthy women were selected: 13 lean (G1) and 7 overweight (G2). The test diets HSD (23% sucrose) and HLD (45% lipid) were calculated for intake under non-restrictive conditions during 14 days. Anthropometry, body composition, plasma glucose and leptin determinations were carried out. The fasting and postprandial plasma leptin values were higher in G2 (p< 0.05), correlating positively with the anthropometry and body composition data (p< 0.05), and special positive correlation with hip circumference. Glucose and leptin concentrations did not differ between diets. Circulating glucose 30 (p< 0.01) and 60 (p< 0.05) minutes after ingestion of HSD were positively correlated with postprandial leptin concentration. The results confirm the positive association between plasma leptin concentration and body fat, specifically the subcutaneous fat tissue, and suggest that more studies are necessary to identify the modulating role of energy intake and macronutrients profile on leptin concentration.
Assuntos
Glicemia/análise , Gorduras na Dieta/metabolismo , Sacarose Alimentar/metabolismo , Leptina/sangue , Obesidade/metabolismo , Adulto , Antropometria , Composição Corporal/fisiologia , Registros de Dieta , Ingestão de Energia/fisiologia , Feminino , Humanos , Estudos Prospectivos , Estatísticas não ParamétricasRESUMO
O presente estudo teve como objetivo investigar o efeito da ingestão de dietas ricas em sacarose (DRS) e em lipídio (DRL) nas concentrações de glicose e leptina plasmáticas. Foram selecionadas 20 mulheres hígidas, 13 com peso normal (G1) e 7 com sobrepeso (G2). As dietas testes DRS (23,0 por cento de sacarose) e DRL (45,0 por cento de lipídio) foram calculadas para consumo em condições de vida livre, por 14 dias. Foram realizadas determinações de antropometria, de composição corporal, de glicose e leptina plasmáticas. Os valores de leptina plasmática de jejum e pós-prandiais foram maiores em G2 (p< 0,05) e correlacionaram-se positivamente com os dados antropométricos e de composição corporal (p< 0,05), destacando-se sua correlação positiva com a circunferência do quadril. As concentrações de glicose e leptina de jejum e pós-prandiais não diferiram entre as dietas. A glicemia nos tempos de 30 (p< 0,01) e 60 (p< 0,05) minutos após a ingestão de DRS correlacionou-se positivamente com a leptinemia pós-prandial. Os resultados confirmam a relação positiva entre a leptinemia e a gordura corporal, especificamente com o tecido adiposo subcutâneo e indicam que mais estudos são necessários para identificar o papel modulador da ingestão energética e do perfil de macronutrientes na leptinemia.
The aim of this study was to investigate the effect of ingesting high-sucrose (HSD) and high-lipid diets (HLD) on the concentrations of plasma glucose and leptin in lean and overweight women. Twenty healthy women were selected: 13 lean (G1) and 7 overweight (G2). The test diets HSD (23 percent sucrose) and HLD (45 percent lipid) were calculated for intake under non-restrictive conditions during 14 days. Anthropometry, body composition, plasma glucose and leptin determinations were carried out. The fasting and postprandial plasma leptin values were higher in G2 (p< 0.05), correlating positively with the anthropometry and body composition data (p< 0.05), and special positive correlation with hip circumference. Glucose and leptin concentrations did not differ between diets. Circulating glucose 30 (p< 0.01) and 60 (p< 0.05) minutes after ingestion of HSD were positively correlated with postprandial leptin concentration. The results confirm the positive association between plasma leptin concentration and body fat, specifically the subcutaneous fat tissue, and suggest that more studies are necessaries to identify the modulating role of energy intake and macronutrients profile on leptin concentration.