[Experimental study on aqueous areca nut extracts inducing oral submucous fibrosis in rats. I. Observation of histomorphology].

The purpose of this study was to establish the animal model of oral submucous fibrosis (OSF) in buccal mucosa of SD rats by submucosa injecting and surface painting aqueous areca nut extracts (AANE). The animals of all groups were killed randomly in the 12th, 16th, 22nd and 28th week. The buccal mucosae were collected, and were detected by light microscope and transmission electron microscope. The results were obtained: at different stages, the OSF-like lesions appeared in different degrees among some animals of the model groups, including atrophic epithelium with loss or partial loss of rate pegs, inflammation, accumulation and disorder of collagen fibre in juxta-epithelial region, along with concomitant muscle degeneration. The lesions didn't reverse obviously themselves after the authors stopped using AANE. Histomorphologic changes didn't appear in any animal of the control groups. The results indicated that the typical and stable OSF animal model were induced rapidly by submucosa injecting and surface painting AANE.