Stress/Aggressiveness-Induced Immune Changes Are Altered in Adult Rats Submitted to Neonatal Malnutrition

Abstract

Background/Aims: Neonatal malnutrition induces metabolic and endocrine changes that have beneficial effects on the neonatal in the short term but, in the longer term, these alterations lead to maladaptations. We investigated the effect of neonatal malnutrition on immune responses in adult rats submitted or not to an aggressiveness test. Methods: Male Wistar rats were distributed to one of two groups according to their mothers’ diet during lactation: the well-nourished group (group C, n = 42, receiving 23% of protein) and the malnourished group (group MN, n = 42, receiving 8% of protein). After weaning, all rats received normoproteic diet. Ninety days after birth, each group was subdivided into three subgroups: control rats (n = 14, respectively), aggressive rats (n = 14, respectively) and rats receiving foot shock (FS; n = 14, respectively). Plasma corticosterone concentration was measured after FS sessions. Leukocyte counts and humoral immunity were evaluated. Results: In neonatal malnourished animals, FS-induced stress reduced plasma corticosterone concentration. Intraspecific aggressiveness induced alterations in leukocyte counts and antibody titers 7 and 15 days after immunization. Neonatal malnourished animals showed no changes in the immune parameters evaluated. Conclusions: Expression of intraspecific aggressiveness activates the immune system. Neonatal malnutrition seems to have a long-lasting effect on components of both neuroendocrine and immune functions.

Effects of maternal high fat intake during pregnancy and lactation on total cholesterol and adipose tissue in neonatal rats

“…In our previous studies it was shown that malnutrition during pregnancy and lactation can promote lasting effects on the offspring (Barreto-Medeiros et al, 2007;Melo et al, 2011). We also found in previous studies that maternal intake of high fat diet, promoting hypercholesterolemia (Oliveira et al, 2011;Perez et al, 2015), increased visceral fat and hepatic steatosis in rats in adulthood (Perez et al, 2015).…”

Perinatal Malnutrition Programs Sustained Alterations in Nitric Oxide Released by Activated Macrophages in Response to Fluoxetine in Adult Rats

“…The impairment of bone marrow cell proliferation in undernourished animals and humans assayed in pregnancy or after birth is well documented [25] ; however, studies exploring these long-term effects are scarce. Although alterations in primary lymphoid organs were not investigated in the present study, and no difference was found in the differential or total counts of peripheral blood leukocytes (the latter according to Barreto-Medeiros et al [15] , using the same malnutrition model), we do not discard the hypothesis that the reduction in cell number and AMs in the BAL fluid is a consequence of perinatal malnutrition. We also found reductions in viability after culture in vitro in AMs from malnourished rats, a response that may be linked to apoptosis [26] .…”

“…The dams' daily RDB consumption caused energy and protein malnutrition in the nestlings, which replicates the malnutrition observed in children [11] . RDB consumption by animals reproduces many changes observed in humans such as cardiovascular and renal alterations, a modified response to antidepressants, and secondary immunodeficiency [11,15,16] . These effects may be due to maternal nutritional deficiencies during the nursing period.…”

“…The ontogeny of the vertebrate immune system requires a rigorously regulated series of events that includes the production of hematopoietic cells, migration of cells through organs, cell-to-cell interactions during cytodifferentiation and acquisition of definitive functional properties [6,7] . Malnutrition in the course of the perinatal phase appears to damage the development and differentiation of the normal immune system [15,23] . In our study, the environmental challenges during the nursing period caused injuries to the immune system that persisted into adult life despite the switch to a normal diet.…”

Perinatal nutrition programs neuroimmune function long-term: mechanisms and implications

“…A calorie restricted perinatal diet has also been shown to influence macrophage activation in adulthood so that adult rats undernourished during lactation had fewer alveolar macrophages and these released less nitric oxide in response to a fluoxetine challenge (Ferreira et al, 2009). Similarly, adult rats undernourished during lactation showed no change in immune parameters after an immune challenge either under control conditions or after being subjected to footshock, while control rats (normal diet during lactation) had elevated leukocyte counts and antibody titers (Barreto-Medeiros et al, 2007). These data suggest neonatal malnutrition can lead to a less reactive or less efficient immune response.…”