ALTERED INTESTINAL DEVELOPMENT AFTER JEJUNAL LIGATION IN FETAL SHEEP

Experimental obstruction of the fetal small intestine resulted in mass ive hypertrophy of the segment proximal to the site of obstruction. Vi llus morphology was grossly abnormal. Enterocytes developed many irreg ular features, most notably cytoplasmic extensions (pseudopods, or ble bs) from their apical surface. Distal to the site of obstruction, morp hological anomalies which resembled those seen after experimental oeso phageal ligation were found. These included delayed disappearance of t he apical endocytic network, disrupted or absent microvilli, glycogen accumulation and inappropriate cell extrusion. Proximal to the obstruc tion, where stasis of swallowed fluid occurs, distension and abnormal intestinal development ensues. Distal to the obstruction where the int estine develops in the absence of swallowed fluid, development is also abnormal. The anomalies resemble those noted after oesophageal ligati on in utero, and possibly are the results of reduced cellular nutritio n. These results suggest that fetal ingestion provides the developing gastrointestinal tract with an important stimulus for normal growth.