DIAMINE AND POLYAMINE OXIDASE ACTIVITIES IN PHYTOHEMAGGLUTININ-INDUCED GROWTH OF RAT SMALL-INTESTINE

The activities of diamine and polyamine oxidases, two enzymes of polyamine catabolism, were studied in hyperplastic growth of rat small intestine induced by phytohaemagglutinin. This growth, evaluated by the elongation of Lieberkuhn's crypts, was more extensive in the proximal than in the distal parts of the gut. The activity of diamine oxidase was significantly reduced in the proximal (70%), medial (45%) and the distal (25%) parts. The activity of polyamine oxidase was doubled. The concentrations of putrescine, cadaverine and spermidine were significantly elevated in the three intestinal parts studied, whereas those of histamine and spermine were unchanged. It appears that changes in the activities of diamine and polyamine oxidases may contribute to the increased putrescine content, which is necessary to maintain active polyamine turnover for sustaining growth of the gut.