Os efeitos do farelo de aveia e da farinha de soja na resposta imune humoral de ratos alimentados com dieta hipercolesterolêmica / The effects of oat bran and soy flour on humoral immune response in rats fed hypercholesterolaemic diets

Estudos anteriores têm demonstrado os efeitos sobre o sistema imune e sobre os níveis de colesterol da dieta com fibra solúvel e proteína de soja em ratos. Nesse estudo, nós avaliamos os efeitos do farelo de aveia e da farinha de soja na resposta imune humoral de ratos Wistar tratados com dietas hipercolesterolêmicas. Os animais (6 grupos) foram alimentados com diferentes dietas por 6 semanas e inoculados duas vezes com antígeno (IgY). As amostras de plasma foram coletadas após cada inoculação e os níveis de anticorpos anti-IgY (IgM, IgG1 e IgG2a) foram avaliados por ELISA. Os animais que receberam 1% de colesterol apresentaram um aumento de IgG1 anti-IgY e uma redução de IgM e IgG2a anti-IgY em relação aos animais controle. Estes efeitos foram anulados em animais alimentados com 1% de colesterol e farelo de aveia ou aveia + proteína de soja, mas não em animais alimentados com 1% de colesterol e proteína de soja. As dietas contendo 1% de colesterol resultaram em lesões hepáticas e aumentaram o peso relativo do fígado e do baço, mas não afetaram o perfil lipídico, o ganho de peso e o consumo de alimentos ou eficiência na conversão alimentar. Em conclusão, uma dieta com alto teor de colesterol influencia na produção de classes de anticorpos em resposta a um antígeno de forma que pode ser revertida pelo farelo de aveia.

Previous studies have demonstrated the immunological and hypercholesterolaemic effects of soluble dietary fibre and soy protein in rats. In this study, we evaluated the effects of oat bran and soy flour on humoral immune response in Wistar rats fed hypercholesterolaemic diets. Animals (6 groups) fed with different diets for 6 wks were inoculated twice with antigen (IgY). Plasma samples were collected after each inoculation and anti-IgY antibody (IgM, IgG1 and IgG2a) levels were evaluated by ELISA. Animals receiving 1% cholesterol presented an increase in anti-IgY IgG1 and a reduction in anti-IgY IgM and IgG2a relative to control animals. These effects were abrogated in animals fed 1% cholesterol and oat bran or oat bran+soy protein, but not in animals fed 1% cholesterol and soy protein. Diets containing 1% cholesterol resulted in hepatic lesions and higher liver and spleen relative weights, but did not affect lipid profile, weight gain, food intake, or food conversion efficiency. In conclusion, a high-cholesterol diet influences classes of antibodies produced in response to an antigen in a way that can be reversed by oat bran

Effects of chronic caffeine intake and low-intensity exercise on skeletal muscle of Wistar rats.

Caffeine can affect muscle cell physiology and the inflammatory response during exercise. The purpose of this study was to analyse muscle damage markers and inflammatory cell infiltration into the soleus muscle of sedentary and exercised animals submitted to chronic caffeine intake. Thirty-two male Wistar rats were divided into the following four groups (n = 8 per group): sedentary control (SCO); sedentary + caffeine (SCAF); trained control (TCO); and trained + caffeine (TCAF). The animals were housed in individual cages and received tap water or caffeine (1 mg ml(-1)); they were maintained at rest or submitted to swimming for up to 40 min day(-1) with a 4% load, five times per week for 30 days. Blood samples were collected for analysis of serum lactate, creatine kinase and calcium. The right soleus muscle and the epididymal fat depot were weighed, and the muscle was submitted to histological analysis. Training and caffeine did not change body or muscle weight, food and liquid intake or serum calcium levels among groups. Decreased fat tissue (P < 0.05) was observed in the SCAF (4.05 ± 1.03 g), TCO (4.14 ± 0.78 g) and TCAF groups (4.02 ± 1.02 g) compared with the SCO group (5.31 ± 1.06 g). Serum creatine kinase activity was significantly reduced in the SCAF (787.3 ± 230.3 U l(-1)), TCO (775.3 ± 232.3 U l(-1)) and TCAF groups (379.5 ± 110.5 U l(-1)) compared with the SCO group (1610.2 ± 276.5 U l(-1)). Few damaged muscle fibres (P < 0.05) were found in SCAF (16.7 ± 12.8%) and TCAF groups (17.3 ± 11.7%) compared with the SCO group (53.6 ± 13.9%). The SCAF group presented fewer fields with inflammatory cells (7.6 ± 8.7 fields) compared with the SCO group (123 ± 146 fields). The results suggest that the chronic intake of caffeine, as well as chronic low-intensity exercise, decreased muscle damage and inflammatory infiltration into skeletal muscle.

Efeito do treinamento físico no pulmão de ratos submetidos à ingestão alcoólica / Effects of physical training on lungs of rats submitted to alcohol intake

O alcoolismo crônico provoca alterações nos tecidos pulmonares caracterizadas por edema pulmonar e formação de extenso infiltrado inflamatório. O objetivo deste trabalho foi avaliar o efeito do exercício físico sobre as lesões pulmonares provocadas por ingestão crônica de álcool em ratos Wistar. MATERIAL E MÉTODOS: Trinta e dois ratos Wistar machos (261,1 ± 1,3 gramas) receberam aguardente de cana-de-açúcar diluída (30 por cento, v/v, grupo alcoolizado) ou água potável (grupo controle) durante 120 dias. Após este período, cinco animais de cada grupo foram sacrificados. Os demais animais receberam apenas água potável até o final do experimento e foram divididos em quatro grupos: alcoolizados sedentários (AS), controle sedentários (CS), alcoolizados treinados (AT) e controles treinados (CT). Os animais AT e CT foram submetidos a protocolo de natação, aumentando gradativamente o tempo de exercício até 20 minutos por dia, cinco vezes por semana, durante um período total de cinco semanas. Neste mesmo período, os animais AS e CS foram mantidos em sedentarismo. RESULTADOS: Após o período de ingestão alcoólica, os animais do grupo alcoolizado apresentaram redução de peso (P < 0,05) e aumento da massa relativa do pulmão (P < 0,05). O pulmão do grupo alcoolizado apresentou edema pulmonar e extenso infiltrado inflamatório. Os animais dos grupos CS e CT não apresentaram diferenças morfológicas. Os animais do grupo AT apresentaram aumento do quadro de edema pulmonar e do número de macrófagos pigmentados em relação ao grupo AC (P < 0,05). CONCLUSÃO: O exercício físico pode acentuar o processo inflamatório pulmonar quando aplicado em animais com lesão pulmonar inflamatória provocada pelo consumo crônico de álcool.

Chronic alcohol consumption causes alterations in the lung tissues characterized by edema and formation of large inflammatory infiltrate. The purpose of this work was to evaluate the effect of physical exercise on lung injuries caused by chronic alcohol intake in Wistar rats. MATERIAL AND METHODS: Thirty-two male Wistar rats (261.1 ± 1.3 g) received sugarcane distilled alcoholic beverage diluted (30 percent, v/v, alcohol group) or tap water (control group) for 120 days. After this period, five animals of each group were sacrificed. The remaining animals received water and were sorted in four groups: alcoholic and sedentary (AS), control and sedentary (CS), alcoholic and trained (AT) and control and trained (CT). The AT and CT groups were submitted to a swimming exercise protocol with progressive daily increase in the training time until 20 minutes per day, five times per week, for five weeks. For the same period, AS and CS groups were maintained at sedentary state. RESULTS: after the alcoholic intake period, the alcohol group presented decreased (P<0.05) body weight and increased relative lung weight (P<0.05). Lungs of alcoholic group showed characteristics of edema and inflammatory infiltrate. The CS and CT groups did not present morphological changes. AT animals showed increased inflammation and number of hyper pigmented macrophages in relation to CT group. CONCLUSION: exercise can increase lung inflammation when applied in animals with inflammatory injury induced by chronic alcohol consumption.