Biochemical and morphological changes in the digestive tract of rats after prenatal and postnatal malnutrition.

Six-week-old rats subjected to prenatal and postnatal dietary restriction (maternal and weanling intake = 50% that of controls) were studied. Compared with controls, malnourished rats not only had reduced body (78 +/- 12 vs 187 +/- 21 g) and organ weights (small intestine: 4.51 +/- 0.46 vs 9.89 +/- 0.61 g; colon: 0.75 +/- 0.08 vs 1.77 +/- 0.18 g; liver: 2.75 +/- 0.34 vs 9.13 +/- 1.33 g; pancreas: 0.78 +/- 0.14 vs 1.67 +/- 0.49 g) but also decreased body weight-length ratios (6.5 +/- 0.3 vs 10.8 +/- 1.4 g/cm) and serum albumin levels. The small intestinal mucosa was hypotrophic (protein-DNA ratio: 5.02 +/- 1.43 vs 8.82 +/- 0.68, malnourished vs controls, respectively) with reduced mucosal thickness, villus height, and crypt depth. Specific activities of lactase, maltase, and sucrase were diminished (53%, 66%, 54% of control values, respectively). Colonic mucosa was hypoplastic with decreased mucosal thickness and crypt depth. Liver and pancreas were both hypotrophic and hypoplastic. The findings suggest that, in contrast to colonic mucosa, pancreas, and liver, the small intestinal mucosa maintained cell number during prolonged prenatal and postnatal malnutrition.