Intestinal repair in chronically undernourished rabbits

To assess the effect of chronic undernutrition on intestinal epithelial repair after injury, we studied 10-wk-old rabbits, nutritionally deprived for 6 wk (body weight 1.95 +/- 0.2 kg versus controls, 2.68 +/- 0.7 kg, p less than 0.001). Intestinal structure and function were assessed 4, 24, 48, 72, or 96 h after a 90-min vascular occlusion of a 20-cm segment of midintestine in undernourished and control-diet animals. Tritiated thymidine autoradiography showed that movement of epithelial cells along the crypt-villus axis was significantly curtailed in undernourished rabbits after sham operation or after ischemic injury. In sham-operated rabbits, no significant differences were observed in mucosal structure, disaccharidase and Na-K-ATPase activities, or Na transport (Ussing chambers) between nutritionally deprived and control diet rabbits. Four and 24 h after ischemic injury, significant but similar structural and functional small intestinal abnormalities occurred in both diet groups; recovery of enzyme function was not significantly delayed but crypt-villus length recovery was minimally delayed in undernourished rabbits. Glucose-stimulated Na absorption diminished in short circuited jejunum from malnourished but not from control diet animals 24 h after injury and was normal in both diet groups at 72 h. After transient small intestinal villus cell injury we observed suppressed epithelial proliferation but no consistent impact on epithelial differentiation in nutritionally deprived rabbits.