Primary Cultures for Studies of Cell Regulation and Physiology in Intestinal Epithelium

The transport functions of intestinal epithelium are critical to health, and defects in these functions underlie clinical conditions such as diarrhea, mucoviscidosis, and malabsorption of sugars, iron, lipids, and bile acids. Many of these conditions can be reversed by direct intervention using pharmacological agents, but inherited genetic defects such as cystic fibrosis (71) and glucose-galactose malabsorption (91) represent a different challenge for therapy. The development of new pharmacological agents depends upon physiological studies to identify, characterize, and understand the regulation of these cellular processes. Traditional techniques for studying transport processes, such as patch clamping and Ussing chambers, depend on ex vivo manipulation of mucosa. This has been achieved by physically dissecting sheets of mucosa (15) and by isolating intact crypt and villus epithelium with divalent ion chelating solutions (17). These methods provide important insights into transport function, but the short-term viability of the isolated cells is an important limiting factor. Organ culture was initially used as a method to maintain cell,S ex vivo for longer periods, but tissue cultured in this way was also