Association of diamine oxidase and ornithine decarboxylase with maturing cells in rapidly proliferating epithelium.

Diamine oxidase and ornithine decarboxylase activities are shown to have a parallel distribution across rat small intestine mucosa; levels of both enzyme activities are sharply higher in mature cells in the villus tip region than in proliferating cells in the crypt areas. Histidine decarboxylase levels were not measurable in the same cell preparations and aromatic-L-amino-acid decarboxylase activity was distributed in an opposite pattern to diamine oxidase and ornithine decarboxylase. The results suggest that intestinal diamine oxidase could be involved with polyamine metabolism. The new findings for ornithine decarboxylase suggest an in vivo role for polyamines in non-proliferative cells; rat small intestinal mucosa may be an excellent model for investigating the function of polyamines in regenerating cells.