EFFECTS OF PROTEIN RESTRICTION IN EARLY-LIFE ON GROWTH AND FUNCTION OF THE GASTROINTESTINAL-TRACT OF THE RAT

Background: Undernutrition during early life may have both immediate a nd later consequences. This study was undertaken to measure the long-t erm effects of perinatal undernutrition on the growth and function of the gastrointestinal tract. Methods: Pregnant rats were assigned to on e of four groups that received isocaloric diets restricted in protein during pregnancy or lactation and during both or neither. Thereafter, their pups were followed until aged 1 year. Results: At 21 days the bo dy weights of the young of those born of dams with postnatal protein r estriction were halved, with comparable reductions in the weights of t he stomach and caecum, compared with those of control animals. The len gths of the small and large intestines and mucosal weights of the fore gut were also significantly reduced. Lactase activities were significa ntly increased and sucrase and maltase activities significantly reduce d. By 42 days all the effects were less marked, and at 1 year the dime nsions of the organs of the gastrointestinal tract and the composition and enzyme levels of the mucosa were all insignificantly different re lative to body weight. Conclusions: Prenatal protein restriction alone had no significant long-term negative effects on body weight, growth, or mucosal hydrolase activity of the gastrointestinal tract. Postnata l protein restriction had a marked effect on these indices in early li fe and delayed the changes in mucosal hydrolases usually seen at weani ng. In contrast with other organs and their functions, long-term growt h of the gut and activity of small intestinal hydrolases are preserved in the face of perinatal protein restriction.