Effect of nutritional rehabilitation on the development of intestinal brush border disaccharidases of postnatally malnourished weanling rats
Rossi, T.M.; Lee, P.C.; Young, C.M.; Lerner, A.; Lebenthal, E.
Pediatric Research 20(8): 793-797
ISSN/ISBN: 0031-3998 PMID: 3090509 DOI: 10.1203/00006450-198608000-00019
The reversibility of the effects of postnatal malnutrition on the intestinal brush border enzymes and somatic and intestinal weights were examined using either ad libitum or restricted feedings. Malnutrition was induced in the immediate postnatal period by expanding newborn rat litters to 20 pups/dam. At 21 days of age, malnourished pups exhibited significantly decreased body and intestinal weights as compared to those from control litters. Malnourished pups also had significantly elevated lactase specific activities whereas sucrase and maltase activities were not affected in the proximal small intestine. With subsequent nutritional rehabilitation by an ad libitum (food available 24 h/day) or restricted feeding regimen (food available 2 h/day), body and intestinal weights remained significantly depressed by 56 days in malnourished as compared to control animals. Rats on 2-h feedings consumed approximately 35% of the food consumed by their ad libitum-fed counterparts. Comparison of the ratio of weight gained to the amount of food consumed did not demonstrate a greater food efficiency with any particular feeding pattern. With ad libitum or restricted feedings, lactase specific activity in the proximal segment attained control values by 14 days. Restricted feedings resulted in an apparent elevation of specific activity of sucrase and of maltase, when rats were sacrificed at one chosen time point. Multiple time studies in a 24-h cycle showed that maximal elevations in enzyme activities were associated with feeding time. There were no significant differences in mean specific daily enzyme activities between the two feeding regimens. Restricted feedings show no advantage in enzyme efficiency or in promoting the rate of recovery of the intestine after postnatal malnutrition.