What are granulosa cells

Granulosa cell

Synonym: granule cell, granule cell

1 definition

In the Granulosa cell it is a specific type of epithelial cell located in the ovarian follicle. The name granulosa cell is derived from the Latin term for grain - granum.

2 localization

The granulosa cells are located in the multi-layered granule cell layer (stratum granulosum) in the area of ​​the ovarian follicle.

3 development

The granulosa cells develop under the influence of gonadotropins - primarily FSH - during follicular maturation from the follicular epithelial cells of the primary follicle. This turns the primary follicle into the secondary follicle.

4 function

The inner layer of the follicle wall forms in the mature tertiary follicle and eventually grows into an egg mound (Cumulus oophorus). The egg cell should then later attach itself to this egg mound. The granulosa cells take over the secretion of the fluid that is ultimately supposed to fill the follicular cavity. Furthermore, after the follicle rupture, the granulosa cells form a layer that wraps around the egg cell. This shell formed by the granulosa cells is called the corona radiata and lies on the outside of the zona pellucida of the egg cell.

An important function of the granulosa cells is the synthesis of steroid hormones. Before ovulation, they form estradiol from the androgenic precursor steroid androstenedione through the enzymatic activity of aromatase.

After ovulation, some granulosa cells remaining in the ovary store lipids. This process is called luteinization. Through this process, the granulosa cells transform into granulosalutein cells and form the corpus luteum, which produces the hormone progesterone.

To control the female cycle, the granulosa cells also produce the proteohormone inhibin, which suppresses FSH production.

To protect the egg reserve in women of childbearing age, the granulosa cells produce the anti-Müllerian hormone. On the one hand, AMH protects the primordial follicles from being recruited too quickly; on the other hand, it counteracts too rapid degeneration of the oocytes and increased atresia of the follicles.