Experimental epithelial dysplasia produced by excisional wounding and application of Trp‐P‐2 in the hamster tongue

All 10 groups of hamsters received excision of the tip of tongue. Subsequently, 3 groups in which tongues were treated with Trp‐P‐2 (3‐amino‐1‐methyl‐5H‐pyrido[4,3‐b] indole) and then again excised in their tips followed by no treatment or by additional applications of DMSO or Trp‐P‐2, showed moderate to severe epithelial dysplasia. One group in which tongues were not treated and then again excised followed by applications of Trp‐P‐2, exhibited very slight epithelial dysplasia. However, one group in which tongues were treated with DMSO and then again excised followed by additional applications of DMSO, did not show any pathological changes. The remaining 5 groups in which tongues were treated with DMSO or Trp‐P‐2 or received no treatment and then not excised followed by no treatment or by additional applications of DMSO or Trp‐P‐2, also did not show any pathologic changes. These results clearly indicated that Trp‐P‐2 treatment together with two times of excisional wounding could produce lingual epithelial dysplasia in hamsters.