Pre-weaning undernutrition alters the expression levels of reactive oxygen species enzymes but not their activity levels or lipid peroxidation in the rat brain

It has been hypothesised that the increased life span commonly observed in rodents that have had their diet restricted after weaning may be related to its effects on the anti-oxidant defence systems. However, undernutrition during the gestation and pre-weaning period is known to have long-term deleterious effects on a rodent's growth and development, and it has been suggested that this may reduce their life span. We have now examined some of the anti-oxidant defence system in rats that have been undernourished from conception until 21 postnatal days-of-age, followed in some cases by a period of nutritional rehabilitation until 62 days of age. We found that such undernutrition could modulate the mRNA expression of Cu/ZnSOD and catalase in some brain regions. However, only catalase showed any undernutrition-induced change of enzyme activity level. There was some evidence that undernourished (but not control) rats had an age-related increase in the level of lipid peroxidation between 21 and 62 days of age, although the group × age interaction was not statistically significant. There was no significant change in the level of reduced glutathione induced by the pre-weaning period of undernutrition. If ROS and the extent of oxidative damage are truly implicated in the determination of life span, our results indicate that this is unlikely to be markedly affected by the relatively small changes we have observed in the anti-oxidant defence systems induced by undernutrition of rats from conception until weaning.