In vitro model for the assessment of luminal factors on rectal mucosa.

An organ culture method for the maintenance of rectal biopsies over a period of 24 hours is described. Good preservation of histological architecture and continued crypt cell proliferation were shown over the culture period. The colonic enzyme alkaline phosphatase was found to rise over the period of culture. This rise was dependent upon continued protein synthesis by the cell. Changes in alkaline phosphatase activity during culture in biopsies from patients with ulcerative colitis and Crohn's disease are reported. This organ culture system and the measurement of alkaline phosphatase activity during culture provides a new approach to the assessment of luminal antigens as possible effectors of colonic epithelial cell damage.