Using microradioautography, the origin of the gastric parietal (and zymogen) cells was deduced by observing the time of appearance of labelled parietal cells in relation to the other labelled cells i n the gastric mucosa. In order to see whether the parietal cell divides in the adult mouse, time grain count curves of the labelled parietal cells were made from animals which were killed at 1-291 days after thymidine SH injection DPT). Parietal cell survival was followed by observing the disappearance of the labelled parietal cell population. Parietal cells appear to be entirely derived from other cells since a significant number of labelled parietal cells does not appear unless the animal is allowed to survive for several days. Parietal cells do not seem to undergo mitosis in the adult mouse because the time grain count curves did not shift with time. Although a few labelled parietal cells persisted in the 291 DPT animals, a large majority of the labelled parietal cells disappeared by 90 DPT and had a half life of roughly 23 days. This suggests an element of renewal for the parietal cell population.

No abstract

A comparative histological and histochemical study of the gastric mucosa was done with the frog, mouse, rat, hamster, guinea pig, rabbit, cat, dog and man. Enzymatic histochemical studies were done to demonstrate acid phosphatase (PbS and azo-dye methods), thiamine pyrophosphatase (TPP-ase) and NADHz tetrazolium reductase activity. Cytoplasmic organelles were stained in some cases by three of the above methods i.e. acid phosphatase (PbS) activity marked the lysosomes, TPP-ase activity marked the Golgi apparatus and NADHz tetrazolium reductase activity marked the mitochondria. The acid phosphatase activity of the four major cell types was markedly different in the various species. The activity shown by both methods in individuals of a given species coincided well except in the rabbit and the dog. TPP-ase activity demonstrated the Golgi region in the surface cells of all species except the guinea pig and the frog. The Golgi zones of zymogen cells showed strong activity only in the cat, while the parietal cell Golgi was not demonstrated in any of the species. NADHz tetrazolium reductase activity in the parietal cells was strong in all animals except the mouse and the rat where staining was faint. The relationship between the lysosomes and the Golgi apparatus, as demonstrated histochemically in the gastric cells of the nine species, is discussed. The functional significance of these different enzymatic patterns has yet to be determined.

No abstract

No abstract