The development of a method for the preparation of rat intestinal epithelial cell primary cultures.

We describe a reproducible method for growing small intestinal epithelium (derived from the suckling rat intestine) in short-term (primary) cultures. Optimal culture conditions were determined by quantitative assays of proliferation (i.e. changes in cellularity and DNA synthesis). Isolation of the epithelia and, significantly, preservation of its three-dimensional integrity was achieved using a collagenase/dispase digestion technique. Purification of the epithelium was also facilitated by the use of a simple differential sedimentation method. The results presented below support the idea that proliferation of normal gut epithelium ex vivo is initially dependent upon the maintenance of the structural integrity of this tissue and upon factors produced by heterologous mesenchymal cells. Proliferation in vitro was also critically dependent upon the quality of the medium and constituents used. Cultures reached confluence within 10-14 days and consisted of epithelial colonies together with varying amounts of smooth-muscle-like cells. Cultures have been maintained for periods up to one month, but the longer-term potential for growth by sub-culturing has not been examined. Strategies for reducing the proliferation of these non-epithelial cells are also described.