ABSTRACT
A technique is presented which yields single cells and intact crypts in suspension from unfixed rat intestinal mucosal epithelium. Everted lengths of intestine were digested by 27 mM sodium citrate in phosphate-buffered saline (pH = 7.3) at 37 degrees C. Mucosal cells were dislodged by vibratory stress (hand vortexing) following incubation for prescribed intervals at 37 degrees C in 1.5 mM ethylenediamine tetraacetic acid (EDTA) and 0.5 mM dithiothreitol (dtt). Alkaline phosphatase determinations, phase microscopy, and in vivo and in vitro evaluations of tritiated thymidine ([3H]TdR) incorporation were performed on isolated intestinal cells. Data indicate that cells were sequentially derived from villus tip to crypt base as judged by cellular morphology, alkaline phosphatase activity/mg protein and radioactivity per microgram protein. Upon completion of the intestinal cell isolation assay, scanning electron microscopy of the remaining intestine revealed that approximately 95% of the crypt openings were vacant; the villi were totally denuded; the supporting structures, including the lamina propria, appeared intact. In vitro radiolabelling of intestinal cell fractions enriched with crypts revealed a linear incorporation of [3H]TdR from 0-60 min which was strongly influenced by the presence of foetal calf serum (FCS). Measurements of the compensatory response of the mucosa to resection of 70% of the small bowel indicated that the mucosal cell separation is capable of detecting alterations in crypt cell proliferation. Previously, such alterations were monitored by other methods utilizing microdissection procedures or stathmokinetic agents.
