Imunonutrição em colite experimenta: efeitos benéficos dos ácidos graxos ômega-3 / Immunonutrition in experimental colitis: benefical effects of omega-3 fatty acids

Recent data have given emphasis to the benefits of immunonutrition with omega-3 fatty acids (n-3 FA) in various clinical situations. This work presents the results of parenteral administration of different lipid emulsions in experimental acute colitis and reviews the pertinent literature. METHODS: Seventy-four adult male Wistar rats were randomized in six groups that had 10% acetic acid-induced colitis (except CS). During 7 days, control groups CS (without colitis) and CC (with colitis) received physiological solution and the others received specific lipid emulsion by a central venous catheter (0.5 mL/h). The n-3/n-6 FA ratio and lipidic compositions were: group L--1:7.7 (LCT, n = 12), M--1:7.0 (MCT and LCT, n = 12), LW-3--1:4.5 (LCT plus FO, n = 12) and MW-3--1:3.0 (MCT and LCT plus FO, n = 13). Rats were evaluated to assess abdominal and intestinal alterations, macrophage cellularity and colonic concentrations of LTB4, LTC4, PGE2 and TXB2. RESULTS: N-3 FA treated rats (LW-3 and MW-3) presented less inflammatory abdominal alterations than CC rats. Mucosal ulcer formation in MW-3 group was the only comparable to CS group. Only CS, M and MW-3 rats presented smaller cellularity than CC group. Comparing to CC group, there were found smaller averages of LTB4 in CS, LW-3 and MW-3 groups, of PGE2 in CS, M and MW-3 groups, and of TXB2 in CS and MW-3 groups. LTC4 averages were not different. CONCLUSIONS: 1) LCT-containing lipid emulsion with low n-3/n-6 ratio do not modify inflammatory colitis derived manifestations; 2) the association of MCT/LCT-containing lipid emulsion with fish oil with high n-3/n-6 ratio impels great beneficial impact, attenuating morphological and inflammatory consequences and decreasing colonic concentrations of proinflammatory mediators

Padronizaçäo tecnica e histologica de colite experimental com acido trinitrobenzenosulfonico (TNBS) / Technical and histological standardization of experimental colitis with trinitrobenzene sulfonic acid

A tentativa de reproduzir doença inflamatoria experimental no colon gerou varios modelos de colite. Desde os trabalhos pioneiros de Morris e col., soluçöes de acido 2,4,6-trinitrobenzesulfonico (TNBS) vem sendo utilizadas em diferentes doses. Os objetivos deste trabalho foram padronizar a induçäo de colite, avaliar os efeitos clinicos (peso, ingestäo diaria, diarreia) e intestinais (alteracçös morfologicas do intestino inflamado) da utilizaçäo de soluçöes com TNBS e atestar a reprodutibilidade do processo inflamatorio. Utilizaram-se ratos Wistar submetidos a introduçäo por via retal de 2,5 ml de soluçöes contendo diferentes concentraçöes de TNBS a 5 por cento diluido em etanol...