Distribution of Laminin on Experimental Periodontitis in Mouse

Observation by Confocal Scanning Laser Microscopy

Abstract

Morphological evaluation of the three-dimen-sional relationship between organ and tissue ele-ments is essential for the study of normal tissue formation and the analysis of periodontal lesions. With conventional methods of observation relying on two-dimensional histological specimens, it has often been difficult to make three-dimensional observations. Laminin, which is found in the extracellular matrix, has a variety of functions, and various strdies have described the distribution of laminin in periodontal tissue. The present study was undertaken to observe the three-dimensional distribution of laminin in mouse periodontal tissue with a confocal laser microscope, and to examine the distribution of laminin during the onset of exper-imental periodontitis.
A confocal laser microscope was used to follow changes in the distribution of laminin in the peri-odontal tissue of normal mice and mice with experi-mental periodontitis. Histological observations using hematoxylin-eosin staining and three-dimen-sional analyses of the distribution of extracellular matrix laminin by the indirect fluorescent antibody method were performed, and the following results were obtained.
1. In normal mouse periodontal tissue, laminin was located in the basal membrane of the gingival epithelium and in the vessels and nerves of the lamina propria of the gingiva. Three dimensional examination of laminin distribution provided three -dimensional pictures of the arrangement of the basal membrane, the morphology and distribution of the papillae in the lamina propria mucosae and the distribution of vessels and nerves.
2. Laminin was also detected in the internal basal lamina of normal mouse periodontal tissue.
3. During the onset of experimental peri-odontitis in mice, laminin was located in the basal membrane of the gingival epithelium and in the vessels and nerves of the lamina propria of the gingiva. Laminin was also detected in inflamed areas (gingival epithelium and lamina propria of the gingiva).
These findings indicate that three-dimensional examination with a co-focal laser microscope is useful in determining the distribution of extracel-lular matrix laminin in normal periodontal tissue and in periodontal tissue during the onset of experi-mental periodontitis. This technique provided three-dimensional images of the arrangement of the laminin-containing basal memberane, the morphol-ogy and distribution of the papillae in the lamina propria mucosae, and the arrangement of vessels and nerves in the periodontal tissue of the normal mouse. Observations by this technique also revealed the presence of laminin in inflamed gin-gival epihelium and the lamina propria of the gin-giva as the region of periodontitis expanded.