Cell death in early burn wounds in guinea pig skin

Abstract

yasUne Deparbnent of Dermatology, Kyoto Prefectural University of Mediclnc, Kyoto, Japan. In a preliminary study, we induced second and third degree bum wounds in guinea pig skins with various heat-stresses. Second and third degree bum wounds were made with heat-stress of 43°C for 5 minor 180% for 3 set respectively. The wounds were removed 1, 3, 6,12, and 48 hrs after burn. The specimens were processed for TUNEL staining or transmission electron microscopy. TUNELpositivc cells were uniformly dishibuted in a second degree bum wound, but narrowly distribukd to the periphery of the central portion of a third degree burn wound. Positive cells were first found in the granular cell layers of the epidermis at 3 hrs, and then found in the granular and basal cell layers at 6 hrs. Positive cells developed in the whole epidennal cells at 12 hrs and in the deep dermis and follicles at 48 hrs after burn. Electron microscopic findings demonstrated the characteristics for apoptosis or necrosis in TLJNBL-positive epidermis. Furthermore, endothelial cell death was first found in the capillaries of upper dermis beneath the vesicle and then developed to the deep perifollicular capillaries with time in spite of intact follicular keratinocytes. The present findings demonstrate that TUNEL-positive cells show cell death by apptosis or necrosis and that burn wounds are nxtde first with direct heat-stress and then with local ischemia.