Efeito da suplementação dietética com L-arginina em subpopulações linfocitárias de ratos submetidos a esplenectomia total isolada ou combinada com autoimplante esplênico / Effect of dietary supplmentation with L-arginine on lymphocyte subpopulations of rats submitted to total splenectomy isolated or combined with splenic autoimplantation

A L-aginina é reconhecida como um nutriente de fundamental importância na resposta imune, apesar de seus efeitos serem, por vezes, considerados inconstantes. O autoimplante esplênico tem sido proposto como alternativa à esplenectomia total isolada, mas existem preocupações quanto à eficácia do restabelecimento da resposta imune, haja vista que o paciente pode permanecer com risco aumentado de desenvolvimento de infecção fulminante pós esplenectomia, mesmo após a regeneração morfológica do órgão. O objetivo deste estudo foi avaliar a participação da suplementação dietética com L-arginina em subpopulações linfocitárias no sangue, no baço e nos autoimplantes esplênicos de ratos submetidos a esplenectomia isolada ou combinada com autoimplante esplênico. Foram utilizados 42 ratos Sprague-Dawlay machos, randomicamente distribuídos em seis grupos: 1 - Controle - operação simulada; 2 - esplenectomia total; 3 - esplenectomia total combinada com autoimplante esplênico; 4 - Controle - operação simulada, com suplementação de L-arginina; 5 - esplenectomia total, com suplementação de L-arginina; e 6 - esplenectomia total combinada com autoimplante esplênico, com suplementação de L-arginina. Os animais dos grupos 4, 5 e 6 receberam suplementação de L-arginina, uma vez ao dia, durante 15 dias anteriores a coleta sangüínea realizada imediatamente antes dos procedimentos operatórios (semanas 0 e 12). A dose utilizada foi de 1,0 g/kg/dia, administrada por via intragástrica em bolus. As avaliações foram realizadas por meio de hemograma e citometria de fluxo. A análise estatística utilizou testes paramétricos e não-paramétricos, sendo p<0,05 considerado para a rejeição da hipótese nula. A suplementação com L-arginina acarretou elevação da contagem relativa e absoluta de neutrófilos periféricos, 12 semanas após a realização de esplenectomia total combinada com autoimplante esplênico. A esplenectomia total ocasionou diminuição da contagem relativa de linfócitos T totais, T CD4+...

L-arginine is recognized as a nutrient of fundamental importance in immune implants has been proposed as an alternative to total splenectomy isolated, but there are concerns about the effectiveness of the restoration of the immune response, considering that the patient can remain at increased risk of developing overwhelming postsplenectomy infection, even after morphological regeneration of the organ. The aim of this study was to determine the role of dietary supplementation with L-arginine in lymphocyte subsets in blood, spleen, and splenic auto-transplantation in rats subjected to total splenectomy alone or in combination with splenic auto-transplantation. Forty two male Sprague-Dawley rats, were randomly divided into six groups: 1 - Control - sham operation, 2 - total splenectomy, 3 - total splenectomy combined with splenic auto-implants, 4 - Control - sham operation, with L-arginine supplementation, 5 - total splenectomy, supplemented with L-arginine, and 6 - total splenectomy combined with splenic auto-implants, supplemented with L-arginine. Animals in groups 4, 5 and 6 were supplemented with L-arginine, once daily for 15 days before blood sample was collected immediately before the operative procedures (weeks 0 and 12). The dose was 1.0 g/kg/day administered by intragastric bolus. The laboratory evaluations were made by blood count and flow cytometry. Statistical analysis used parametric tests and nonparametric, p<0.05 was considered to reject the null hypothesis. Supplementation with L-arginine led to increase in relative and absolute count of peripheral neutrophils, 12 weeks after completion of total splenectomy combined with splenic auto-implants. Total splenectomy caused a decrease in relative count of T lymphocytes, CD4+ and CD8B in blood, but dietary supplementation with L-arginine prevented the decrease in the percentage of total T cells and CD8B in the blood of animals subjected to splenic auto-transplantation...

Efecto de la Arginina sobre el sistema inmunológico y parámetros nutricionales en pacientes con cirugías abdominales complicadas / Effect of Arginine on the inmune system and nutritional parameters in patients wth complicated abdominal surgery

La suplementación de la nutrición enteral con Arginina a dosis mínima (6 g. día) desde el primer día de alimentación posterior a una cirugía abdominal complicada tendría efectos sobre la respuesta inmunológica y los niveles de proteínas plasmáticas. Se encontró un aumento significativo del Recuento Total de Linfocitos y de los niveles de Transferrina en el grupo que recibió la Arginina. Las demás variables no tuvieron una variación significativa...

Immunonutrition.

Nutrition and immunology are interrelated. Several nutrients like arginine, glutamine, omega-3-fatty acids and nucleotides enhance cellular immunity, modulate tumor cell metabolism and improve clinical outcome in stress situations. Glutamine supplementation has been shown to decrease incidence of sepsis and to reduce length of hospital stay in bone marrow transplant patients, low birth weight infants, surgical and multiple trauma patients. Studies with arginine have shown a reduction in infectious complications and lower mortality, however a better understanding of the biology of arginine is needed. Omega-3-fatty acid supplimentation as in fish oil stimulates the immune system. The beneficial effects of immunonutrition in surgical patients has been demonstrated in several studies. It significantly reduces infectious complications and length of hospital stay. In critically ill patients immunonutrition may decrease infectious complications but it is not associated with a mortality advantage. Pediatric experience is limited, but the future is promising.

Killing of blood stage Plasmodium vinckei petteri by spleen macrophages through L-arginine dependent mechanism.

A series of experiments was carried out to investigate the involvement of the L-arginine-dependent effector mechanism (LADEM) in the killing of the blood stages of the rodent malaria parasite, Plasmodium vinckei petteri, by activated spleen macrophages in vitro. P.v.petteri-infected red blood cells were co-incubated with spleen macrophages from normal mice which had previously received 10(8) Mycobacterium bovis (BCG) 5 days earlier, in the presence of 0.1 microgram/ml LPS with and without 0.1 mM L-NMMA, an L-arginine analogue which inhibits LADEM, for 16 hours. The viability of the parasites was assessed according to their infectivity following inoculation into experimental mice. Incubation of parasites with spleen macrophages in the presence of LPS without L-NMMA reduced the parasite viability to about 3%. When L-NMMA was included in the culture, inhibition of parasite killing was observed, resulting in an increase of parasite viability to about 21%. These data provide evidence to suggest that spleen macrophages play an important role as effector cells in the immune mechanisms against P.v.petteri infection, and that the parasite killing of these cells, at least in part, was mediated by LADEM.

Memorias: inmunomodulacion / Memories: immunomodulation

La arginina tiene efectos inmunoestimulatorios, anabolicos y antitumorales. Sus efectos se deben a sintesis de proteinas, poliaminas, nitrogeno, secrecion hormonal y estimulacion de linfocitos T4