ULTRASTRUCTURAL STUDIES OF INFLAMMATION INDUCED IN RATS BY INJECTION OF ANTIGEN-ANTIBODY PRECIPITATES - CHANGES IN PALATAL BONE AND PERIOSTEUM TO A SINGLE EXPOSURE

Single intramucosal injectins of ferritin‐antiferritin into the palate adjacent to the 1st molar produced a dense neutrophil infiltration within perivscular tissue adjacent to the palatal bone. Neutrophil degranulatin related to the phagocytosisi of antigen‐antibody (Ag‐Ab) precipitates occurred during the 1st 24 hours post injection. Rapidly developing bone damage was characterized by periosteal disruption, osteoblast and osteocyte necrosis and occasional swquestration of necrotic bone. Cytoplasmic changes such as dilated endowere observed inosteoblasts within 2 hrs of Ag‐Ab injection. Wound healing with regeneraionof periosteal tissue at the margins of the lesion was observed to begin at 4 days post injection. New bone was formed directly over the older necrotic bone without any intervening bone resorption. Extracellular matrix vesicles were observed adjacent ot newly differentiated bone cells. Copyright © 1979, Wiley Blackwell. All rights reserved