CYTOPHOTOMETRIC AND AUTORADIOGRAPHIC EVALUATION OF CELL KINETICS IN DECIDUAL GROWTH IN RATS

Abstract

Summary. Because of endopolyploidy, cell kinetics in decidual growth are best studied by cytophotometric methods. This technique was applied to smears of nuclei isolated from decidualizing endometrial stroma at various moments after uterine scratching in hormonally prepared rats. After a 48-hr lag period, the production of polyploid nuclei was accelerated. At its maximal development (96 hr), the decidual tissue contained few cells other than polyploid cells, the highest level attained being 32c. During decidualization, there was a progressive increase in labelling with [3H]thymidine and in mitotic indices up to the 3rd day. It is suggested that endopolyploidy results in this case from by-passing mitosis by cells lacking some rate-limiting metabolic factor indispensable to the mitotic phase.