DETECTION OF CHOLECYSTOKININ-B GASTRIN RECEPTOR MESSENGER-RNA EXPRESSING CELLS IN THE STOMACH OF HYPERGASTRINEMIC RATS/

Enterochromaffin-like (ECL) cells, which are numerous in the oxyntic m ucosa of the rat stomach, proliferate in the presence of hypergastrine mia. We investigated the distribution of cells expressing gastrin rece ptor (GR) in Sprague-Dawley rats in hypergastrinemia was induced by ga stric corpectomy. The ECL cell density was determined by immunohistoch emical staining for histamine. The expression of GR mRNA was investiga ted using digoxigenin-labeled complementary RNA probes. The labeling i ndex of the generative cell zone was determined by H-3-thymidine autor adiography. The ECL cell density and the labeling index in the generat ive cell zone increased in association with increased plasma levels of gastrin after 24 weeks (p<0.05). The expression of GR mRNA was seen n ot only in ECL, generative, parietal and chief cells, but also in stro mal cells of hypergastrinemic rats. The expression of GR mRNA became m ore marked in the oxyntic mucosa as plasma levels of gastrin increased , and it was suggested that GR mRNA expression acts as one indication in the development of ECL cell hyperplasia.