CELL KINETIC IN EPITHELIUM AND STROMA OF BENIGN PROSTATIC HYPERPLASIA

The induction of benign prostatic hyperplasia (BPH) from normal prosta te is obviously associated with a distinct increase in epithelial and stromal proliferation. We have shown previously that the further incre ase of BPH volume in aging men is not associated with a further increa se in proliferation. We studied whether an imbalance between programme d cell death (apoptosis) and cell proliferation may explain continuing growth in aging men. In prostates of 17 men with BPH removed by open prostatectomy proliferating cells were localized immunohistochemically with the Ki-67 antibody. Apoptotic cells were detected with the termi nal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelin g (TUNEL) method. Proliferation and apoptotic index was calculated wit h a computer assisted image analysis system. Mean proliferation index +/- standard deviation in epithelium (0.142 +/- 0.097) and stroma (0.1 21 +/- 0.082) was nearly identical. Mean apoptotic index in epithelium (0.172 +/- 0.156) was negligibly higher than the corresponding prolif eration index. In stroma, however, no apoptotic cells were detectable. Proliferation index and apoptotic index in epithelium and proliferati on index in stroma showed no correlation to patient age or prostate vo lume. In the epithelium of BPH, obviously the cell kinetic is balanced . On the other hand, our results indicate stromal growth due to cell p roliferation in the absence of cell death. This may explain the contin uous increase of BPH volume in aging men.