Histological and Immunohistochemical Study of Effects of TGF-.ALPHA. and Trp-P-2 on Transplanted Organ-cultured Mouse Tooth Germ

Abstract

In the present study, the effects of both growth factor TGF- α and carcinogen Trp-P-2 on the development of organ-cultured ddY mouse tooth-germ which was transplanted into the subcutaneous tissue of nude mice were investigated histologically, immnohistochemically (PCNA) and histometrically in 5 groups of mice, namely Group A (Control), Group B (DMSO), Group C (TGF-α), Group D (Trp-P-2) and Group E (TGF-α + Trp-P-2). Histologically, in Groups C, D and E, marked proliferation of odontogenic epithelial cells was observed. In Groups D and E, keratinization of the odontogenic epithelial cells was found, but it was not observed in Group C. Moreover, in Group E, a cyst-like space was observed in the area of odontogenic epithelial cells. Immunohistochemically, in Groups C, D and E, PCNA-positivities of the odontogenic epithelial cells were significantly higher than those of Group A. Histometrically, in Groups C and E, the size of the tooth germ was significantly larger than that of Group A. The results of the present study suggest that proliferation, keratinization, cyst-like space formation of odontogenic epitherial cells of transplanted organ-cultured tooth germs in mice were promoted by growth factor TGF- α and carcinogen Trp-P-2.