Stress/aggressiveness-induced immune changes are altered in adult rats submitted to neonatal malnutrition.
OBJECTIVE
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.
Barreto-Medeiros
Jairza
J
School of Nutrition, Federal University of Bahia, Bahia, Brazil. jmbm@ufba.br
Queiros-Santos
Adenilda
A
Cabral-Filho
José Eulálio
JE
Ferreira E Silva
Wylla Tatiana
WT
Leandro
Carol Góis
CG
Deiró
Tereza Cristina
TC
Manhaes-de-Castro
Raul
R
Machado Barbosa de-Castro
Célia Maria
CM
D000374:Aggression / Q000502:physiology* / Q000523:psychology; D000375:Aging / Q000276:immunology*; D000818:Animals; D000906:Antibodies / Q000097:blood; D000917:Antibody Formation / Q000276:immunology; D001522:Behavior, Animal / Q000502:physiology; D003345:Corticosterone / Q000097:blood / Q000378:metabolism; D004195:Disease Models, Animal; D005508:Food Deprivation / Q000502:physiology; D006801:Humans; D007107:Immune System / Q000503:physiopathology*; D007223:Infant; D007228:Infant Nutrition Disorders / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology; D007231:Infant, Newborn; D007958:Leukocyte Count; D008297:Male; D044342:Malnutrition / Q000276:immunology* / Q000378:metabolism / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar; D012919:Social Behavior; D013315:Stress, Psychological / Q000276:immunology* / Q000378:metabolism / Q000503:physiopathology; D013995:Time
D000906:Antibodies; D003345:Corticosterone