Myeloperoxidase activity in skin lesions. I. Influence of the loss of blood, depth of excoriations and thickness of the skin.

The measurement of the myeloperoxidase activity was used to quantify the acute granulocyte reaction. A 35% loss of blood resulted in a clear decrease of the myeloperoxidase activity at the edges of experimental incision wounds in rat skin in the first day after inflicting the wounds. After 12 h only about one-third and after 24 h about half of the activity observed in the wounds without the loss of blood remained. After 3 days however the activity had returned to the same level as in the wounds without any loss of blood. In very deep excoriations of the rat skin where only a narrow zone of the dermis was left about double the activity increase was observed after 12 and 24 h when compared to values observed in very superficial or moderate excoriations. When the same type of excoriations were made in both thin inguinal skin and thick dorsal skin then a much higher peroxidase activity increase was observed over 4, 12 and 24 h in the thin inguinal skin than in the excoriations made in the thick dorsal skin.