Effects of a single pentagastrin injection on diamine oxidase activity in the rat intestinal mucosa.

The effect of a single injection of pentagastrin on diamine oxidase (DAO) activity in the rat intestinal mucosa was examined. The animals of subsequent groups were sacrificed by decapitation at 6, 12 and 24 h after the administration of pentagastrin or 0.9% NaCl (controls). Diamine oxidase activity was also tested in entire animals. The intestinal fragments were rinsed with 0.9% NaCl. The mucosal scrapings were frozen in liquid nitrogen. Diamine oxidase activity increased in the 24 h after the administration of pentagastrin, when compared with respective controls. No significant differences at other times were evident. The present data are in agreement with the hypothesis that DAO is an enzyme involved in the negative feedback control mechanism of intestinal mucosa cell proliferation.