The deleterious effects of maternal protein deprivation on the brainstem are minimized with moderate physical activity by offspring during early life.

Maternal protein malnutrition during developmental periods might impair the redox state and the brain's excitatory/inhibitory neural network, increasing central sympathetic tone. Conversely, moderate physical exercise at an early age reduces the risk of chronic diseases. Thus, we hypothesized that a moderate training protocol could reduce the harmful effects of a low-protein maternal diet on the brainstem of young male offspring. We used a rat model of maternal protein restriction during the gestational and lactation period followed by an offspring's continuous treadmill exercise. Pregnant rats were divided into two groups according to the protein content in the diet: normoprotein (NP), receiving 17% of casein, and low protein (LP), receiving 8% of casein until the end of lactation. At 30 days of age, the male offspring were further subdivided into sedentary (NP-Sed and LP-Sed) or exercised (NP-Ex and LP-Ex) groups. Treadmill exercise was performed as follows: 4 weeks, 5 days/week, 60 min/day at 50% of maximal running capacity. The trained animals performed a treadmill exercise at 50% of the maximal running capacity, 60 min/day, 5 days/week, for 4 weeks. Our results indicate that a low-protein diet promotes deficits in the antioxidant system and a likely mitochondrial uncoupling. On the other hand, physical exercise restores the redox balance, which leads to decreased oxidative stress caused by the diet. In addition, it also promotes benefits to GABAergic inhibitory signaling. We conclude that regular moderate physical exercise performed in youthhood protects the brainstem against changes induced by maternal protein restriction.

Effects of perinatal protein restriction on the oxidative balance in the hypothalamus of 60-day-old rats / Efeitos da restrição proteica perinatal sobre o balanço oxidativo no hipotálamo de ratos de 60 dias de idade

ABSTRACT Objective Evaluate the effects of maternal low-protein diet on the oxidative stress in the hypothalamus of 60-day-old rats. Methods Male Wistar rats were divided into two experimental groups according to the mother's diet during pregnancy and lactation; control group (NP:17% casein n=6) and a malnourished group (LP:8% casein n=6). At 60 days of life, the rats were sacrificed for the collection of the hypothalamus for further biochemical analysis. Results Our results showed an increase in oxidative stress in malnourished group, observed through an increase in carbonyl content (p=0.0357), a reduction in the activity of the glutathione-S-transferase enzyme (p=0.0257), and a reduction in the non-enzymatic antioxidant capacity evidenced by the decrease in the ratio reduced glutathione/oxidized glutathione (p=0.0406) and total thiol levels (p=0.0166). Conclusion A low-protein diet during pregnancy and lactation is closely associated with increased oxidative stress and reduced antioxidant capacity in the hypothalamus of sixty-day-old rats.

RESUMO Objetivo Avaliar os efeitos da restrição proteica materna sobre o estresse oxidativo no hipotálamo de ratos de 60 dias de idade. Métodos Ratos Wistar machos foram divididos em dois grupos experimentais de acordo com a dieta da mãe durante a gestação e lactação: grupo controle (NP: 17% caseína n=6) e grupo desnutrido (LP: 8% caseína n=6). Aos 60 dias de vida, os ratos foram sacrificados para coleta do hipotálamo para posterior análise bioquímica. Resultados Os resultados demonstraram aumento do estresse oxidativo no grupo desnutrido, observado através do aumento do conteúdo de cabonilas (p=0,0357) e redução da atividade da enzima glutationa-S-transferase (p=0,0257) e da capacidade antioxidante não enzimática, evidenciada pela queda da razão glutationa reduzida/glutationa oxidada (p=0,0406) e dos níveis de tióis totais (p=0,0166). Conclusão Uma dieta com baixo teor de proteínas durante a gestação e lactação está intimamente associada ao aumento do estresse oxidativo e à redução da capacidade antioxidante no hipotálamo de ratos de 60 dias de vida.