Neonatal Overfeeding Induced by Reducing the Litter Size Leads to an Obese Phenotype and Increases Preference for Sweet Food in Adult Male Rats.

Aim: the aim of this study was to induce obesity in rats using the neonatal overfeeding protocol and evaluate in adult male animals standard chow intake, sweet food intake, the preference between sweet food and standard chow, locomotor activity and anxiety-like behavior. Methodology: The neonatal overfeeding protocol consisted of reducing the litter size to 4 animals (small litters = SL) compared to 8 animals in normal litters (NL). In these experiments we used 55 offspring from 18 litters. Results: obesity was successfully induced as observed by increased body weight and depots of abdominal fat in SL animals compared to NL; [F(1, 53)=15.018; P<.001] for body weight and [t(48.06)=2.186 P=.03] for abdominal fat.No difference between groups was found in standard chow [t (16)=1.843 P=.08] and sweet food intake [t(53)=0.453 P=.65], however in the test that evaluated the preference between both foods SL animals consumed more sweet food than NL [t(48) =2.481 P=.02]. Additionally, there was no difference between groups regarding locomotor activity [t(52)=0.073 P=.94] but SL animals showed reduced anxiety-like behavior compared to NL [t(39.36)=2.205 P=.03]. Conclusion: this study supports the use of neonatal overfeeding protocol as a model of early obesity and showed for the first time the increased preference for sweet food in adult neonatal overfed animals.

Produção de óxido nítrico no hipocampo: investigação do envolvimento do óxido nítrico sintase neuronal no desenvolvimento de comportamentos ansiosos em animais submetidos a estresse neonatal / Hippocampal nitric oxide production: investigation of the role of neuronal nitric oxide synthase in the development of anxiety-like behaviors in animals subjected to neonatal stress

Introdução: Estudos indicam que o trauma precoce e o sistema serotoninérgico estão relacionados ao desenvolvimento de ansiedade. Esta relação poderia ser mediada pela enzima óxido nítrico sintase neuronal (nNOS), que tem papel importante no funcionamento dos receptores de serotonina. Objetivo: Investigar, através da mensuração do óxido nítrico (NO) no hipocampo, o possível envolvimento da nNOS no desenvolvimento de ansiedade em um modelo animal de adversidade no início da vida, baseado na qualidade do cuidado materno. Métodos: Ao segundo dia de vida, genitoras Wistar e suas ninhadas foram divididas em dois grupos: intervenção, com redução do material para a confecção do ninho, ou controle. O comportamento materno foi observado do dia 1 ao dia 9 de vida. Na vida adulta, realizaram-se testes comportamentais e determinaram-se os níveis hipocampais de NO, através da mensuração de seus produtos de degradação. Resultados: Observou-se um maior comportamento do tipo ansioso no grupo intervenção, cujas genitoras apresentaram maior contato de baixa qualidade com seus filhotes. Nos machos, o cuidado materno de baixa qualidade correlacionou-se negativamente com o tempo no braço aberto e a frequência de mergulhos (r=-0,4;p=0,03) avaliados no labirinto em cruz elevado. O comportamento materno de lamber os filhotes correlacionou-se com a frequência de mergulhos em ambos os sexos (r=0,5;p<0,001). A quantidade de NO no hipocampo não diferiu entre os grupos. Conclusão: Uma maior atividade da nNOS não parece estar envolvida no comportamento ansioso observado neste modelo animal, no entanto a relação mãe-filhote, alterada por um ambiente neonatal adverso, teve impacto sobre o comportamento ansioso de forma sexo específica.

Background: Studies have shown that an adverse early life environment and the serotonergic system are related to the development of anxiety. This association could be mediated by neuronal nitric oxide synthase (nNOS), an enzyme that plays an important role in serotonin receptor functioning. Aim: To investigate the possible role of nNOS in the development of anxiety by measuring hippocampal nitric oxide (NO) in an animal model of neonatal stress, based on the quality of maternal care. Methods: On the second day of life, Wistar dams and their litters where divided in two groups: intervention, with limited access to nesting material, or control. Maternal behavior was observed from day 1 to 9 of life. In adult life, behavioral tests were performed and hippocampal NO levels were determined by measuring its degradation products. Results: There was more frequent anxiety-like behavior in the intervention group, whose dams showed low quality contact with their pups more often. In males, low quality maternal care was negatively correlated with time spent in open arms and frequency of head dips (r=-0.4; p=0.03) assessed using an elevated plus maze. Licking and grooming score was correlated with frequency of head dips in both sexes (r=0.5;p<0.001). Hippocampal NO levels were not different between groups (p=0.992). Conclusion: A higher nNOS activity does not seem to be involved in anxiety-like behavior observed in this animal model, however the relationship between dam and pup, modified by an adverse early life environment, had a different impact on anxiety behavior between sexes.

O impacto da transição demográfico-epidemiológica na saúde da criança e do adolescente do Brasil / The impact demographic and epidemiological transition in the health of children and adolescents in Brazil

Esse artigo tem como objetivo discutir os novos desafios no campo da saúde da criança e do adolescente como conseqüência do intenso processo de transição demográfica e epidemiológica brasileiro. Os aspectos relacionados à assistência, à pesquisa e ao ensino dos profissionais de saúde e, a presença de um novo perfil de saúde e doença, com seus novos mecanismos de causalidade são objetos de reflexão buscando alternativas para o enfrentamento e a superação das dificuldades advindas dessa situação. Portanto, esse artigo tenta desenvolver uma análise crítica desse novo cenário na perspectiva de oferecer as respostas pertinentes para as novas demandas em saúde das futuras gerações de brasileiros.

The objective of the present study was to discuss the new challenges of children and adolescent health care related the intensive process of demographic and epidemiological transition in Brazil. Aspects related to health care, research, and education of health professionals, as well as the presence of a new profile of health and disease, including its new mechanisms of causality, are analyzed with the purpose of offering alternatives to face and overcome the difficulties arising from this situation. Therefore, we tried to conduct a critical analysis of this new scenario in order to provide relevant solutions to the new health demands of the next Brazilian generations.