Wylla Tatiana Ferreira e Silva

Effect of stress on the production of O2− in alveolar macrophages

Abstract Alveolar macrophages (AM) of male rats (200–250 g), stressed or not, were evaluated with relationship to superoxide production (SP). Plasma levels of corticosterone were measured. The control group showed larger SP than the stressed group in all intervals of time. Exposure in vitro of AM to a synthetic glucocorticoid for 40 min (the same time of restraint stress) inhibits SP. Therefore, it seems under stress situations there is an increase of plasma levels of corticosterone and a decrease of SP in AM after stimulation with PMA. O 2 − is a potent microbicide and its reduction could cause the loss of microbicidal activity of AM.

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

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.

Efeito da desnutrição neonatal sobre o recrutamento celular e a atividade oxidante-antioxidante de macrófagos em ratos adultos endotoxêmicos

OBJECTIVE: The objective of this study was to assess if neonatal malnutrition impairs cell recruitment to the lungs and the oxidant-antioxidant activity of alveolar macrophages in adult endotoxemic rats. METHODS: Male Wistar rats (n=48) were divided into two groups and suckled by dams fed experimental diets containing a normal protein content of 23% (nourished group) and a low protein content of 8% (undernourished group) during lactation. After weaning, all animals received a normal protein diet. Between 90 and 120 days, half of each group was submitted to endotoxemia by intraperitoneal administration of 1mg/kg of body weight of lipopolysaccharide. Blood was collected 24 hours after this procedure for total and differential leukocyte count and measurement of nitric oxide. Bronchoalveolar lavage was also done to determine total and differential leukocyte count and measure superoxide, nitric oxide and superoxide dismutase in the macrophages isolated from this lavage. RESULTS: Malnourished animals remained underweight until adulthood. Furthermore, the following also decreased: total blood leukocyte count, number of neutrophils after lipopolysaccharide administration and production of superoxide, nitric oxide and superoxide dismutase before and after induced endotoxemia. CONCLUSION: These results suggest that neonatal malnutrition, even after nutritional recovery, compromises cell recruitment to lungs and the oxidant-antioxidant activity of alveolar macrophages of adult rats. Endotoxemia contributes to evidence these sequelae to the host response before this model of malnutrition.

Atividade antioxidante de macrófagos alveolares em ratos endotoxêmicos

The effects of endotoxemia on the antioxidant activity in alveolar macrophages of Wistar rats were evaluated. Twenty-four male rats, 90-120 days of age, were separated into 2 groups: control and endotoxemic. To the endotoxemic animals was administered, intraperitoneally, a lipopolyssaccaride at dosage of 1mg/kg body weight. Twenty-four hours after this procedure, blood was collected for total and differential leukocytes counts. In addition, bronchoalveolar lavage was collected for total and differential leukocyte counting. From this lavage macrophages were isolated for the dosage of superoxide and superoxide dismutase. The endotoxemia increased the total leukocyte counts and the number of neutrophils in the peripheral blood and bronchoalveolar lavage of the rats. There was an increased superoxide production without changing the superoxide dismutase. Our findings indicate that endotoxemia induces lung inflammatory response. However, it does not alter the antioxidant activity in adult rats. This fact not only enhances host response against infectious agents, but might also contribute to the pathogenesis of pulmonary injury.

Effects of high-fat diet on somatic growth, metabolic parameters and function of peritoneal macrophages of young rats submitted to a maternal low-protein diet.

This study evaluated the effects of a post-weaning high-fat (HF) diet on somatic growth, food consumption, metabolic parameters, phagocytic rate and nitric oxide (NO) production of peritoneal macrophages in young rats submitted to a maternal low-protein (LP) diet. Male Wistar rats (aged 60 d) were divided in two groups (n 22/each) according to their maternal diet during gestation and lactation: control (C, dams fed 17 % casein) and LP (dams fed 8 % casein). At weaning, half of the groups were fed HF diet and two more groups were formed (HF and low protein-high fat (LP-HF)). Somatic growth, food and energy intake, fat depots, serum glucose, cholesterol and leptin concentrations were evaluated. Phagocytic rate and NO production were analysed in peritoneal macrophages under stimulation of zymosan and lipopolysaccharide (LPS)+interferon γ (IFN-γ), respectively. The maternal LP diet altered the somatic parameters of growth and development of pups. LP and LP-HF pups showed a higher body weight gain and food intake than C pups. HF and LP-HF pups showed increased retroperitoneal and epididymal fat depots, serum level of TAG and total cholesterol compared with C and LP pups. After LPS+IFN-γ stimulation, LP and LP-HF pups showed reduced NO production when compared with their pairs. Increased phagocytic activity and NO production were seen in LP but not LP-HF peritoneal macrophages. However, peritoneal macrophages of LP pups were hyporesponsive to LPS+IFN-γ induced NO release, even after a post-weaning HF diet. Our data demonstrated that there was an immunomodulation related to dietary fatty acids after the maternal LP diet-induced metabolic programming.

Biological and behavioral correlates of body weight status among rural Northeast Brazilian schoolchildren

The increase in the prevalence of overweight/obesity in youth is a public health problem worldwide; however, few studies have investigated its prevalence and correlates in children from the Brazilian Northeast region rural zone. The purpose of this study was (1) to estimate the prevalence of childrens weight status according to sex, age, and birth weight categories; and (2) to investigate the links between biological and behavioral factors and weight categories.