DETECTION OF THE KI-67 PROLIFERATION-ASSOCIATED NUCLEAR EPITOPE IN NORMAL CANINE TISSUES USING THE MONOCLONAL-ANTIBODY MIB-1

This report describes the immunohistochemical detection of the Ki-67 p roliferation associated nuclear epitope by means of the MIB-1 monoclon al antibody (mAb) in paraffin tissue sections from nine samples of 16 tissues obtained from nine dogs. Three parameters were considered: the localization of the cells expressing the Ki-67 epitope, the cytologic al characteristics of the Ki-67 expression, and the proliferative acti vity of some of the tissues measured by means of the proliferative ind ex (percentage of Ki-67 positive cells measured on 500 and 1000 cells) . The MIB-1 mAb reacts with the nuclei of proliferating cells, as in h umans. The proliferative index was far from representative, but we wer e able to give a range of values concerning the proliferative activity of normal tissues. This study serves as a basis for the expression of the Ki-67 antigen by normal canine tissues in order to visualize the proliferative compartments and, thus, allows its application as a prol iferative marker in routine veterinarian histopathology.