Histamine catabolism in proliferating skin.

The histamine (HI) content and the activities of the enzymes involved in its degradation have been studied in guinea pig skin after stimulation of epidermal proliferation. As compared with unstimulated skin the HI content and histamine N-methyltransferase (HMT) activity in the stripped skin were reduced at the time of increased epidermal proliferation and were higher than the normal when the epidermis becomes hyperplastic. Diamine oxidase (DAO) followed an inverse pattern.