Organ culture studies of rat antrum: evidence for an antral inhibitor of gastrin release.

The regulation of gastrin release in rodent antral mucosal organ cultures was investigated. The tissue was well preserved morphologically and medium gastrin concentration increased steadily throughout a 24-h culture period. The effects of peptone and a bovine serum albumin digest on gastrin release were independently investigated. During the periods these agents were in contact with the tissue, medium gastrin concentration did not differ from those of control cultures. However, treatment cultures released a significantly greater amount of gastrin into the medium than did control cultures during the two posttreatment periods. Prolongation of the period of exposure to peptone did not alter this secretory pattern. The rise in medium gastrin concentration that followed the removal of peptone was directly related to the medium peptone concentration and was partially inhibited by readdition of peptone to cultured antral explants. These results suggest that substances which stimulate gastrin release in vivo may cause the accumulation of an antral inhibitor of gastrin release when exposed to rat antral mucosa in culture.