Impact of Refeeding on Intestinal Development and Function in Infant Rabbits Subjected to Protein-Energy Malnutrition

Abstract

ABSTRACT. The impact of early postnatal protein-energy malnutrition and of 4, 7, and 14 d of nutritional rehabilitation on small intestinal growth, development, structure and function was examined in 28-, 32-, 35-, and 42-d-old infant rabbits. Malnutrition was induced by litter expansion 7 d postpartum and, in randomly selected malnourished animals, refeeding was begun at weaning, 28 d. Results are compared to ad libitum fed dietary controls. Malnutrition altered the small intestine of the developing rabbit, as evidenced by: 1 ) reduced jejunal and ileal mass as shown by decreased mucosal wt, protein, and DNA content; 2) depressed epithelial proliferation and enterocyte migration along the crypt-villus axis; 3) delayed epithelial maturation as measured by mucosal enzyme activities; and 4) enhanced glucose-stimulated Na+ transport. Refeeding stimulated rapid and complete recovery, as evidenced by: l ) restoration of jejunal and ileal mucosal mass within 4 d; 2) enhancement of epithelial renewal and enterocyte migration by 7 d; and 3) complete return of the normal pattern of mucosal enzymes by 14 d. With 7 d of refeeding, glucose-stimulated Na+ transport was downregulated to the level of dietary controls. We conclude that early postnatal protein-energy malnutrition has a severe impact on small intestinal growth, development, structure, and function. Furthermore, a brief period refeeding induced a rapid and complete recovery of these parameters. In early infancy, the small intestine undergoes a period of rapid growth and development associated with multiple alterations of intestinal structure and function. Also in the immediate postnatal period when nutrient reserves are marginal, the infant is particularly susceptible to intestinal injury. With the refeeding July 17, 1989; accepted October 13, 1989. Correspondence and reprint requests J.

Formula Feeding Predisposes Gut to NSAID-Induced Small Intestinal Injury

“…Previous animal studies have noted that when malnutrition is present, small intestinal development may be altered with decreased jejunal mass and delayed epithelial maturation as measured by mucosal enzymes activities [41]. Because the opposite changes (increased intestinal mass and accelerated maturation) were found in our formula-fed animal groups, we conclude that the formula-fed rat pups were not malnourished at the completion of study and that our findings are not secondary to malnutrition.…”

Proabsorptive Effects of Modified Tapioca Starch as an Additive of Oral Rehydration Solutions

“…This observation is of interest because malnutrition is very often associated with chronic diarrheal illness, especially among children in the underdeveloped world (11‐13). This approach has been introduced in previous studies from our laboratory (6,14‐16) and by other investigators (17‐19). Although induced protein deficiency reduces jejunal absorptive surface(16), mucosal weight, epithelial proliferation, and enterocyte migration(18) in rats or rabbits, it results in enhanced Na‐dependent glucose transport, attributable to a greater number of mucosal carriers which translates into a greater rate of glucose transport(J max ) (19).…”

Importance of Milk and Diet on the Ontogeny and Adaptation of the Intestine

“…These changes include a fall in lactase activity and an increase in sucrase and Na+/K+APTase activities. In malnourished animals, there is a delayed fall in ileal BBM lactase activity as well as a late rise in jejunal and ileal sucrase activities (72). These findings confirm and extend previous observations in infant rats (68) and rabbits (73) that suggest that early nutrient deprivation delays postnatal maturation of BBM enzyme activity.…”

“…The specific activity of thymidine kinase, an enzyme normally associated with cell division in the intestinal crypts, is diminished in the distal segment of the malnourished rat pups (68). In general, the delay in postnatal development of mucosal enzyme activity caused by early postnatal malnutrition recovers rapidly with the institution of adequate nutrition (72). A brief period of refeeding leads to complete recovery of intestinal structure, mucosal mass, epithelial kinetics, and mucosal function in severely malnourished infant rabbits.…”