[Action of HCG on isolated and cultivated sow ovarian granulosa cells]

Granulosa cells harvested from cavitary follicles of varying diameters have been cultivated in vitro in basic conditions and in presence of HCG, and then tested for the activity of steroid-3 beta-ol-dehydrogenase and observed with a scanning electron microscope. As concerns the enzymatic activity, the cells of the smaller follicles (5--6 mm) show a very low reactivity which increases in presence of HCG. In the cells of the larger antral follicles (8--9 mm) the reactivity is remarkably higher, particularly when HCG is added to the medium. With the scanning electron microscope the appearance of the granulosa cells of the larger follicles cultivated with HCG is very peculiar because of the presence on the cell surface of many cytoplasmic evaginations. These are more numerous and thinner than those normally found on the uncultured cells and on the cells cultivated in basic conditions.