3-DIMENSIONAL ULTRASTRUCTURE OF APOPTOTIC NUCLEI IN RAT PROSTATIC EPITHELIAL-CELLS REVEALED BY A QUICK-FREEZING AND DEEP-ETCHING METHOD

BACKGROUND. To clarify intranuclear apoptotic changes, we have investi gated chromatin organization in apoptotic nuclei of castrated rat pros tatic cells by a quick-freezing and deep-etching (QF-DE) method. METHO DS. The ventral prostates taken from intact and castrated adult male r ats were investigated by light microscopy, in situ end-labeling (ISEL) technique, conventional electron microscopy, and the QF-DE method. RE SULTS. In control nuclei, the chromatin fibers were uniformly distribu ted and formed a network structure. In apoptotic nuclei, destruction o f such chromatin networks was detected, which was clearly seen by the QF-DE method. Although it first appeared spotty in the apoptotic nucle us, definite destruction of the intranuclear network occurred in the n uclear center at later stages, and broken fibrous structures were cond ensed along the nuclear margin. The ISEL technique was applied to the QF-DE method. Localization of damaged DNA fragments could three-dimens ionally be detected on replica membranes. CONCLUSIONS. Intranuclear ch romatin organization in apoptotic cell death of rat prostates was obse rved by the QF-DE method. We could examine early-stage apoptotic nucle i at an electron microscopic level, which would not be clarified by ot her conventional methods. (C) 1998 Wiley-Liss, Inc.