Avaliação da gliconeogênese hepática em ratos adultos submetidos à desnutrição proteica em fases críticas do desenvolvimento e recuperados com dieta à base de farinha de soja

Abstract

Objective: We investigated whether nutritional recovery on a soybean flour diet alters hepatic gluconeogenesis. Methods: Male rats from mothers that were fed either 17% or 6% protein during pregnancy and lactation were maintained on a 17% casein (CC, LC), 17% soybean flour (CS, LS) or 6% casein (LL) diet after weaning. Basal serum glucose and FFA levels were determined and assays for gluconeogenic enzymes expression activity, glucagon sensitivity test, pyruvate tolerance test and liver glycogen concentrations were performed in adult animals in the fasting state. Results: Soybean diet reduced basal serum glucose and free fatty acid levels, liver glycogen content, lactate dehydrogenase mRNA expression and activity, but increased alanine aminotransferase and phosphoenolpyruvate carboxykinase mRNA expression as well as glicerokinase protein content. Serum glucose concentration and phosphoenolpyruvate carboxykinase activity were increased in rats submitted to protein restriction in early life. The glucose area under the curve during glucagon sensitivity test was reduced by early malnutrition and by soybean diet, whereas glucose area under the curve during pyruvate tolerance test did not differ among groups. Conclusion: Soybean diet reduced basal serum glucose levels without to alter gluconeogenesis. The low basal serum glucose levels appear to have resulted from reduced liver glycogen store due to increased glucogenolisis and/or reduced glucogen synthesis.