Morphological Changes in the Lingual Papillae and Their Connective Tissue Cores on the 7,12-dimethylbenz[α]anthracene (DMBA) stimulated Rat Experimental Model

• Published in: Okajimas Folia Anatomica Japonica Vol. 85; no. 4; pp. 129 - 137
• Main Authors: ZHENG, Jinhua, XIE, Liping, TENG, He, LIU, Shilong, YOSHIMURA, Ken, KAGEYAMA, Ikuo, KOBAYASHI, Kan
• Format: Journal Article
• Language: English
• Published: Japan Editorial Board of Okajimas Folia Anatomica Japonica 01.02.2009
• Subjects: 9,10-Dimethyl-1,2-benzanthracene - toxicity; Animals; Carcinogens - toxicity; Connective Tissue - drug effects; Connective Tissue - ultrastructure; Connective tissue cores; DMBA; Epithelium - drug effects; Epithelium - ultrastructure; Lingual papillae; Male; Microscopy, Electron, Scanning; Precancerous Conditions - chemically induced; Rat; Rats; Rats, Sprague-Dawley; Scanning Electron Microscope (SEM); Tongue - drug effects; Tongue - ultrastructure
• ISSN: 0030-154X; 1881-1736
• DOI: 10.2535/ofaj.85.129

The aim of the study was to analyze morphological changes of the epithelial surface and underlying connective tissue cores (CTCs) of the lingual mucosa in the rat using a DMBA induced pre-cancerous experimental model. Lightmicroscopically, initially DMBA treated sections exhibited infiltration of chronic inflammatory cells. At 16 weeks, aldehyde-fuchsin (AF) positive elastic fibers decreased and were scanty in the juxtaepithelium. On the other hand, rather densely packed thick bundles of AF positive fibers were observable in the deep layers of lamina propria. Carcinomas were not found at any stage, however, epithelial dysplasia was observed at 24 weeks post-treatment with DMBA. Scanning electron microscopy revealed an irregular arrangement of filiform papillae 4-12 weeks following DMBA stimulation. Patchy degenerated areas were observed especially at 16-24 weeks post-treatment and filiform papillae were totally attenuated on the central part of the degenerated areas. After removal of the epithelium, attenuated CTCs were observed from 4-8 weeks. Morphology of CTCs seemed to be gradually remodeled and severely altered in the later stage. The CTCs were however attenuated and exhibited a patchy distribution. The animal experimental model in this study revealed degenerative morphological changes of CTCs of the lingual papillae in the precancerous stage induced by DMBA.