Capacidade aeróbia de ratos alimentados com dieta rica em frutose Aerobic capacity of rats fed with fructose rich diet

INTRODUÇÃO: Evidências apontam que a ingestão exacerbada de frutose pode desencadear distúrbios característicos da síndrome metabólica. OBJETIVOS: Analisar os efeitos da ingestão de dieta rica em frutose sobre aspectos metabólicos de ratos da linhagem Wistar. Adicionalmente, verificar a capacidade aeróbia através da identificação da máxima fase estável de lactato (MFEL). MÉTODOS: Dezesseis ratos foram separados em dois grupos de oito animais: a) controle, alimentados com dieta balanceada, e b) frutose, alimentados com dieta rica em frutose. Foram analisadas a tolerância à glicose (área sob a curva de glicose durante teste de tolerância à glicose), sensibilidade à insulina (taxa de remoção da glicose sérica após sobrecarga exógena de insulina), perfil lipídico sérico e concentração de lactato sanguíneo [lac]s durante exercício na intensidade da MFEL. RESULTADOS: Teste t não pareado (p < 0,05) revelou diferença para a tolerância à glicose e triglicérides, porém não houve diferença na sensibilidade à insulina e na [lac]s. Anova one way com post hoc de Newman-Keuls (p < 0,05) revelou diferença para a cinética da glicose durante o teste de tolerância, mas não para a cinética do lactato durante exercício na MSSL. CONCLUSÃO: As Alterações fisiológicas provocadas pela dieta rica em frutose e inerentes à síndrome metabólica não prejudicam a capacidade aeróbia de ratos.<br>INTRODUCTION: Evidence points that exacerbated ingestion of fructose may trigger disturbs characteristic of the metabolic syndrome. OBJECTIVES: To analyze the effects of a fructose rich diet on metabolic aspects of Wistar lineage rats. Additionally, to verify the aerobic capacity, through the identification of the maximal lactate steady state (MSSL). PROCEDURES: Sixteen rats were separated in two groups of eight animals: a) Control, fed a balanced diet, and b) fructose, fed a fructose-rich diet. The glucose tolerance, (area under serum glucose during a glucose tolerance test), insulin sensibility (glucose disappearance rate after exogenous insulin administration), serum lipid profile and blood lactate concentration [lac]b during exercise at MSSL intensity, have been analyzed. RESULTS: Non-paired t test (p<0.05) revealed difference between groups in the area under the curve of glucose and serum triglycerides, no difference in insulin sensibility or in [lac]b was detected, though. One-way ANOVA with Newman Keuls post hoc revealed difference in the glucose kinetics during tolerance test, but not in the lactate kinetics during the MSSL. CONCLUSION: The physiological alterations promoted by fructose-rich diet and intrinsic to the metabolic syndrome do not harm the aerobic capacity of rats

Oral sensitization to whey proteins induces age- and sex-dependent behavioral abnormality and neuroinflammatory responses in a mouse model of food allergy: a potential role of mast cells

Abstract Background Growing evidence has strengthened the association of food allergy with neuropsychiatric symptoms such as depression, anxiety, and autism. However, underlying mechanisms by which peripheral allergic responses lead to behavioral dysfunction are yet to be determined. Allergen-activated mast cells may serve as mediators by releasing histamine and other inflammatory factors that could adversely affect brain function. We hypothesized that eliciting food allergy in experimental animals would result in behavioral changes accompanied by mast cell accumulation in the brain. Our hypothesis was tested in a mouse model of milk allergy using bovine milk whey proteins (WP) as the allergen. Methods Male and female C57BL/6 mice at 4 weeks (young) and 10 months (old) of age underwent 5-week WP sensitization with weekly intragastric administration of 20 mg WP and 10 μg cholera toxin as an adjuvant. Age-matched sham animals were given the vehicle containing only the adjuvant. All animals were orally challenged with 50 mg WP in week 6 and their intrinsic digging behavior was assessed the next day. Animals were sacrificed 3 days after the challenge, and WP-specific serum IgE, intestinal and brain mast cells, glial activation, and epigenetic DNA modification in the brain were examined. Results WP-sensitized males showed significantly less digging activity than the sham males in both age groups while no apparent difference was observed in females. Mast cells and their activities were evident in the intestines in an age- and sex-dependent manner. Brain mast cells were predominantly located in the region between the lateral midbrain and medial hippocampus, and their number increased in the WP-sensitized young, but not old, male brains. Noticeable differences in for 5-hydroxymethylcytosine immunoreactivity were observed in WP mice of both age groups in the amygdala, suggesting epigenetic regulation. Increased microglial Iba1 immunoreactivity and perivascular astrocytes hypertrophy were also observed in the WP-sensitized old male mice. Conclusions Our results demonstrated that food allergy induced behavioral abnormality, increases in the number of mast cells, epigenetic DNA modification in the brain, microgliosis, and astrocyte hypertrophy in a sex- and age-dependent manner, providing a potential mechanism by which peripheral allergic responses evoke behavioral dysfunction