Intestinal Repair in Chronically Undernourished Rabbits

Abstract

ABSTRACT. 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 -C 0.2 kg versus controls, 2.68 f 0.7 kg, p < 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. (Pediatr Res 20: 1301-1304, 1986 Abbreviations Isc, short circuit current Na-K-ATPase, sodium-potassium-dependent ATPase PD, potential difference AIsc, transmucosal Isc Chronic dietary deprivation has been shown in several species to inhibit epithelial renewal in the small intestine (I). We postulated that in the chronically undernourished subject, epithelial repair might be delayed after injury. In fact, a recent study in our laboratory found that chronically under nourished piglets exhibited relatively prolonged recovery from the extensive lesion of experimental viral enteritis (2). The present experiments examine functional and structural intestinal recovery after transient ischemic injury to short segment of mid-small intestine in rabbits subjected to chronic dietary deprivation. MATERIALS AND METHODSBeginning at 4 wk of age, when they weighed 1.2 * 0.2 kg (mean k SEM), New Zealand White rabbits, each day, received 50% of the daily intake of a control ad libitum fed group, for 6 wk. Preliminary experiments had established that any dietary restriction in excess of 50% of control diet caused restlessness, aggressive behavior, and a significant death rate. All rabbits received conventional Rabbit Chow (Ralston Purina Company, Raleigh, NC) and had free access to water. As shown in Figure 1, the deprived diet group gained less weight, 1.95 k 0.2 kg, than the ad libitum fed controls, 2.68 k 0.7 kg (mean k SEM) over the 6-wk study period ( p < 0.00 1).After this 6-wk period, rabbits from both dietary groups, at random, underwent g...

Nutritional Depletion and Dietary Manipulation: Effects on the Immune Response

“…These results could not entirely be confirmed in chronically undernourished rabbits after intestinal ischemia: Only suppression of enterocyte proliferation was observed with no impact on function [35].…”

“…The effects of these changes on intestinal defense mechanisms during stress were demonstrated in chronically undernourished piglets, who were shown to have a significantly delayed anatomic and functional recovery after experimentally induced viral enteritis [34]. These results could not entirely be confirmed in chronically undernourished rabbits after intestinal ischemia: Only suppression of enterocyte proliferation was observed with no impact on function [35].…”