Ultrastructure of human granulosa cells obtained from follicular fluid aspirates

Samples of the granulosa cells obtained from a punctured human preovulatory follicles stimulated for in vitro fertilization purposes were studied by means of light and electron microscopic methods. Early and late preluteinized granulosa cells were characterized by the presence of high amount of pale and homogeneous lipid droplets, moderate accumulation of glycogene and progressive development of smooth endoplasmic reticulum. A new type of granulosa cell containing dense-cored granules with fine granular contents of a secretory nature was identified in this material and discussed in comparison with some earlier published indications of its possible existence.