Physical activity and low protein diet intake during pregnancy in female rats: effects on pregnancy course and fetal development

Para investigar o efeito da exercício físico e da ingestão de dieta hipoprotéica sobre o curso da gestação e o desenvolvimento fetal, ratas W istar com 50 dias e média de massa corporal de 161,lg (± 8,7), foram divididas nos grupos: Normoprotéico Sedentário (NS), Normoprotéico Treinado (NT), Hipoprotéico Sedentário (HS) e Hipoprotéico Treinado (HT). Os grupos “normoprotéicos” receberam dieta com 17% de proteína, e os “hipoprotéicos” com 6% de proteína, as dietas eram isocalóricas. Os grupos treinados realizaram natação 60 minutos por dia, com 5% da massa corporal fixada ao tronco, cinco dias na semana, do lo. ao 17o. dia gestacional. No 19o. dia as ratas foram sacrificadas em repouso, sendo avaliado: a) nas gestantes: glicose, albumina e proteínas totais circulantes; glicogênio no fígado, útero e músculo gastrocnêmio; b) nos fetos: glicose, albumina e proteínas totais circulantes; glicogênio no fígado; teores de DNA e proteína tecidual no cérebro, coração e fígado. NT e HS apresentaram menor ganho de massa corporal que NS e HT. Em relação aos fetos os dos grupos HT e NT tiveram redução na massa corporal em relação aos NS; e os NT e HS menor teor cardíaco de DNA que o NS. Concluindo, treinamento aliado à ingestão de dieta hipoprotéica, porém isocalórica, minimizou os efeitos deletérios dos tratamentos isolados, não havendo alteração no curso da gestação e no desenvolvimento fetalThis study aimed to investigate the effects of physical activity and intake of low protein diet on pregnancy course and fetal development. We used W istar female rats that at the first day of pregnancy, were separated into four groups: Normal (17%) protein diet, Sedentary (NS); Normal protein diet, Trained (NT); Low (6%) protein diet, Sedentary (HS); and Low protein diet, Trained (HT). Exercise training protocol consisted in swimming in individual tanks, filled with water at 31-34°C, 60min day, five days a week, supporting an overload corresponding to 5% of body mass, fixed at the trunk, starting on first day and ending on 17th day of pregnancy. During the experimental period, body mass and food intake were registered. On the 19th day of pregnancy the rats were sacrificed in rest and their fetuses were immediately removed. W e measured maternal serum glucose, total protein, albumin, and free fat acids and muscle, uterus and liver glycogen. W e also measured litter size; fetal body mass, serum albumin, total protein and glucose; cerebrum, liver and heart DNA and protein contents; and fetal liver glycogen. NT and HS dams showed lower body mass and their fetus showed lower body mass and cell number (as indicated by the low DNA contents) than NS group. Furthermore, NT and HS dams exhibited lower body mass increase than HT ones. Serum glucose was higher in HS dams than HT and muscle glycogen in trained groups was higher than sedentary one. Physical activity and malnutrition, alone reduced maternal body mass gain and fetal cardiac cell number. In summary, physical training association to the intake of a low protein, but high glucose diet, partially counteracted the deleterious effects of the two isolated treatments on pregnancy course and fetal developmen