Impairment of inflammatory response in adult rats submitted to maternal undernutrition during early lactation: Role of insulin and glucocorticoid

Objective: Early nutritional environment may program permanent metabolic alterations, predisposing to later diseases. We have investigated the interference of maternal malnutrition during lactation with the development of acute inflammation in adult rats. Material and methods: Adult rats, offspring of dams fed with either protein-free diet (UN group) or 22% protein diet (C group) during the first 10 days of lactation, were submitted to pleurisy with carrageenan (500 mug/cavity). Pleural edema, neutrophil migration and ICAM expression, were evaluated 4 h after and correlated with alterations in plasma insulin and corticosterone. Leukocyte-endothelium interactions were evaluated by intravital microscopy 1 h after inflammation. Results: Compared to controls, UN rats showed a decrease in pleural edema formation (50%), neutrophil migration (50%), endothelial ICAM-1 expression on pulmonary tissue, and impairment in leukocyte adhesion (50%) and migration (80%) through endothelium. Circulating insulin was lower (42%) and corticosterone was higher (34%) in UN, compared to controls. Pre-treatment of UN with insulin (5 IU/day) or RU486 (20 mg/kg/day), inhibitor of glucocorticoid receptor, restored leukocyte functions and ICAM-1 expression. Conclusion: Postnatal maternal malnutrition, programming for permanent alterations in insulin and glucocorticoid secretion in progeny, that were unable to properly mount an inflammatory response, probably predisposes to chronic diseases in adult life.