[Activity of nucleolar organizer regions in trophoblast as affected by hypoxia]

The aim of this study was to investigate the influence of hypoxia on the activity of nucleolar organizer regions (AgNORs) in placentas obtained from healthy women and patients with late gestosis (pre-eclampsia). Chorionic villi from healthy and pre-eclamptic placentas were incubated in hypoxic conditions, AgNORs were detected using silver nitrate impregnation and were counted morphometrically. The results have shown that the exposure to hypoxia resulted in the increase of the area of nuclear profiles, as well as in the augmentation of numbers and surface area of AgNORs in syncytiotrophoblast nuclei. The degree of this increase was minimal in the healthy group and maximal in severe pre-eclampsia. An increase in AgNORs numbers and surface area in syncytiotrophoblast nucei suggests the stimulation of protein synthesis and proliferative activity in late gestosis.