Surface characteristics of cultured adult rat colon using scanning electron microscopy

The surface characteristics of cultured distal colonic mudosa from adult male Fischer 344 rats have been studied under the scanning electron microscope (SEM). Colonic mucosa, physically separated from the submucosa and muscle, was cultured on a matrix of human fibrin foam. The luminal surface of uncultured colonic mucosa formed repeating circular units of cells around individual crypt openings. After 2 days in organ culture, this normal arrangement of surface epithelium was lost. Circular arrangement of cells surrounding the crypts reappeared after 7 days in culture but did not show the well-demarcated crypt units. By 14 days in vitro fewer crypt units were seen; many of these showed a slightly convex contour. Organ cultures retained a variable number of glandular crypts after 21 to 28 days. Occasional epithelial cells were found attached to the interstitial surfaces of the fibrin foam. The organ culture system described appears to be applicable to experimental investigations into the direct effects of various substances on adult colonic epithelium.