Can physical exercise during gestation attenuate the effects of a maternal perinatal low-protein diet on oxygen consumption in rats?

Abstract

A protocol of physical exercise, based on maximal oxygen uptake, for female rats before and during pregnancy was developed to evaluate the impact of a low-protein diet on oxygen consumption during gestation and growth rate of the offspring. Virgin female Wistar rats were divided into four groups as follows: untrained (NT, n = 5); trained (T, n = 5); untrained with low-protein diet (NT+LP, n = 5); and trained with low-protein diet (T+LP, n = 5). Trained rats were submitted to a protocol of moderate physical training on a treadmill over a period of 4 weeks (5 days week-1 and 60 min day-1, at 65% of). At confirmation of pregnancy, the intensity and duration of the exercise was reduced. Low-protein groups received an 8% casein diet, and their peers received a 17% casein diet. The birth weight and growth rate of the pups up to the 90th day were recorded. Oxygen consumption, CO2 production and respiratory exchange ratio (RER) were determined using an indirect open-circuit calorimeter. Exercise training increased by about 20% when compared with the initial values (45.6 ± 1.0 ml kg-1 min-1). During gestation, all groups showed a progressive reduction in the resting values. Dams in the NT+LP group showed lower values of resting than those in the NT group. The growth rate of pups from low-protein-fed mothers was around 50% lower than that of their respective controls. The T group showed an increase in body weight from the 60th day onwards, while the NT+LP group presented a reduced body weight from weaning onwards. In conclusion, physical training attenuated the impact of the low-protein diet on oxygen consumption during gestation and on the growth rate of the offspring. © 2009 The Physiological Society.