Comparative study of AgNOR and PCNA in experimental carcinogenesis of salivary glands of rats.

Previous studies regarding experimental carcinogenesis demonstrated that submaxillar glands (GSM) submitted to DMBA present cellular modifications of progressive gravity in different periods after eight days of the experiment (J. Dent. Res 59: 1067, 1980). This current work pursues the objective of determining, quantitatively, regions of nucleolar organizations (AgNOR) and immunomarkation of the antigen of nuclear proliferation (PCNA) for their possible link with the morphostructural findings previously described. By means of argentic impregnation, the AgNOR were identified. The histometric was performed according to the numeric parameters of AgNOR per nucleus (CABRINI et al. 1992) immersed 1000x. A triple blind reading of the five randomly chosen studies from each of the twenty cases studies with distinct experimentation stages was completed. The results were compared to the normal areas (control group). The PCNA was determined immunohistochemically (Avidina-Biotina System Dako). The average number of AgNOR was 11 after eight days; 16 after fifteen days and 12 after twenty days of the experiment (100% adenocarcinoma). In the control group, the average number of AgNOR did not exceed 6. The PCNA after eight days was negative. The reaction in the tumor area was between 20 and 30% positive. The results indicate an increase in the number of AgNOR in relation to the neoplastic proliferation, corroborated by PCNA immunodetection.