Cell differentiation in human gastric gland as revealed by nuclear binding of tritiated actinomycin.

The nuclear binding of H3 actinomycin, which is closely linked to the differentiation phenomenon, was studied in human normal gastric mucosa. Actinomycin binding decreases in cells which differentiate and becomes very low in fully differentiated cells. In the gastric pits, there is a decreasing gradient of labelling from the deeper stem cells to the well-differentiated superficial cells. This indicates that migration and renewal of the surface epithelium occurs following a 'pipe-line' system. All the undifferentiated stem cells are labelled. Where the parietal cells are concerned all degrees of labelling are observed at various levels with a decreasing proportion of labelling from the surface to the bottom of the gland. With mucous cells and chief cells in the upper part of the gland a great number of poorly labelled mucous neck cells is observed. In the middle and lower part of the gland there is a new growth of heavily labelled cells. This means that in the normal human stomach chief cells probably do not originate from mucous cells.