Haut • Skin • Peau

The methods of enzyme histochemistry seem suitable for detection of the very first reactions in the wounded tissue (cf. Raekallio, Nature 188, 234, 1960). — Circular excision wounds, 5 mm in diameter, were cut in the dorsal skin of several hundreds of albino rats and guinea pigs. The animals were decapitated at intervals of 1/2, 1, 2, 4, 8, 16, 24, 48, 72, 96, and 120 hours after the injury. Skin flaps containing the wounds were removed immediately and frozen fresh or fixed. The activity of the following enzymes was visualized: nonspecific phosphatases, adenosine triphosphatase, nonspecific esterases, β-glucuronidase, transglucosylases, aminopeptidase, cytochrome oxidase, monoamine oxidase, and succinic dehydrogenase. — In the immediate vicinity of the wound edge, a central or superficial zone, 200 to 500 μ in depth, showed decreased enzyme activity in the connective tissue cells. This decrease, commencing one to eight hours after injury, was considered as an early sign of imminent necrosis. Surrounding the central area, a 100 to 300 μ deep peripheral zone exhibited an increase in enzyme activity, appearing one to eight hours after wounding. This initial increase seemed to represent an adaptive defence mechanism by the local connective tissue cells, as a response to injury.