ABSTRACT
This chapter deals with the behavior of diamine oxidase (DAO) activity in some hyperplastic and hypertrophic tissues, and considers some aspects of its control and possible functional significance in growing cells. DAO activity is therefore involved in putrescine catabolism of hyperplastic and hypertrophic tissues, and it may be considered part of a cellular system that also includes the acetylation/oxidation pathway of polyamines for the removal of these substances when a diminution of their levels in the cell is required. In contrast to the large number of investigations on putrescine levels and metabolism in growing tissues, very few studies on the behavior of DAO on other physiological substrates such as histamine and cadaverine1 have been carried out. A substantial histamine formation in tissues undergoing rapid growth and repair has been described. In the hypertrophic kidney and heart of rats treated with this inhibitor, an increase in putrescine levels proportional to the inhibition of DAO activity has been found.
