Cell proliferation in developing human stomach.

Cell proliferation during morphogenesis of human stomach was investigated using radioautography and biochemical determinations of [3H]-thymidine incorporation into DNA. Labeling indices in the epithelium, mesenchyme and muscle layer were established on radioautographs and the heights (mm) of the gastric glands were measured between 10 and 17 weeks of gestation. At 11-12 weeks, the appearance of the first pit/gland was noted, and the labeling index ranged from 9.2 to 10.2%. Labeled cells were present at all levels of the stratified epithelium. Between 14 and 16 weeks, the total epithelial labeling index declined sharply (8.1 to 5.4%) with a concomitant increase of the height of the pit/gland structures (0.055 to 0.080 mm). High proliferative activity was also recorded in the mesenchyme and the muscle layer, the labeling indices decreasing between 10 and 17 weeks. The biochemical quantitation of the [3H]-thymidine uptake into the total gastric DNA clearly supported the continuous decrease of the cell proliferation determined by radioautography. Detailed analysis of the epithelium showed that proliferative cells were more numerous at the base of the gland at the earliest stage (11 weeks) but concentrated in the pit/neck regions by 13-14 weeks. As the pit/gland development proceeded (14 to 17 weeks) labeled cells remained more abundant in the pit/neck regions of the gland (10.9%) and were rarely seen on the surface epithelium (2%). The present investigation provides basic quantitative data regarding cell proliferation in developing human stomach, and indicates that the morphogenesis of the gastric glands is correlated with the high proliferative capacity of the pit/neck cells.