AgNORs during the process of wound healing. Time dependency as evaluated in vital and postmortem biopsy

Silver staining of paraffin sections to detect changes in nucleolar organizer regions (AgNORs) is an established method for detecting cellular proliferation. To determine whether AgNORs are helpful in assessing wound age and vitality, we examined intravital and postmortem skin biopsies from rats surviving incised wounds to both pinnae for defined intervals up to 384 h using, 7 rats per time interval. One biopsy was taken immediately before death, a second 24 h after been sacrificed and storage at 8 degrees C. Interactive computer-assisted image analysis revealed that in the first 120 h after trauma the total number of AgNORs, the mean AgNOR sum area in the nucleus, and the mean AgNOR area per nucleus were dependent on survival time. Taken as indicators of proliferative activity these morphological phenomena revealed an increase in proliferative activity after survival times ranging from 10 to a maximum of 96 h. The findings were the same in both intravital and postmortem biopsies. These findings are in accordance with those obtained using bromodeoxyuridine. The value of these experimental findings in assessing wound age of human beings is discussed.