Morphometric changes in the corpus luteum of pregnant hypokinetic rats.

The aim of this work was to study the influence of hypokinetic conditions on the ovary and corpus luteum of pregnant rats. The rats were kept in hypokinetic conditions for 5 days in the period between the 13th and 18th days of pregnancy. A three-dimensional reconstruction of the ovary and corpora lutea and also a stereological evaluation of the luteal cells and their nuclei were performed using serially cut material. Hypokinesia caused a decrease in the mean volume of the ovary and individual corpus luteum and in the total volume of corpora lutea per ovary in immobilised animals as compared to the control. Moreover, a decrease was observed in the mean number of luteal cells and an increase in the size of these cells, as well as in the mean volume fraction of their nuclei. These results indicate that immobilisation of pregnant rats for 5 days considerably influences the morphology of the corpus luteum and luteal cells.