Effect of gastrin on the cell kinetics of rat gastric mucosa

The effects of gastrin on the cell kinetics of the gastric mucosa were studied in the rats. The labelling index by tritiated thymidine of the cell in the mucous neck zone began to rise 14 hours after a single dose of tetragastrin at 100 or 1,000 microgram/kg or synthetic human gastrin at 1,000 microgram/kg and reached the peak at 18 hours. With tetragastrin 100 microgram/kg administered subcutaneously together with a depot for 35 days, observations were made on the change in the turnover rate of the gastric epithelium by means of labelling index. The turnover rate was delayed in the surface epithelium and accelerated in the cells at the lower part of the foveolae in the gastrin-administered group. The cell suspension prepared from the rat gastric mucosa by trypsin digestion was cultivated with 5 per cent of CO2 in air for 48 hours. The group which was added with 10 microgram/ml of tetragastrin showed fluctuations in the labelling index almost similar to the groups administered 100 and 1,000 microgram/kg in vivo. It might be possible to support the hypothesis that gastrin not only has a trophic effect on the mucous neck zone but it also might be concerned with the turnover of the mature stage of gastric mucosa.