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Cell culture of granulosa cells can be performed in vitro. Plating density (number of cells per volume of culture medium) plays a critical role for the differentiation. A lower plating density makes granulosa cells exhibit estrogen production, while a higher plating density makes them appear as progesterone producing theca lutein cells. [12]
Hyperactivity of theca cells causes hyperandrogenism, and hypoactivity leads to a lack of estrogen. [5] Granulosa cell tumors, while rare (less than 5% of ovarian cancers), may both granulosa cells and theca cells. [6] Thecomas are benign proliferations of theca cells that may present with hormonal dysfunction. [7]
Theca interna cells express receptors for luteinizing hormone (LH) to produce androstenedione, which via a few steps, gives the granulosa the precursor for estrogen manufacturing. [ 1 ] After rupture of the mature ovarian follicle , the theca interna cells differentiate into the theca lutein cells of the corpus luteum .
The granulosa lutein cells do have aromatase, and use it to produce estrogens, using the androgens previously synthesized by the theca lutein cells, as the granulosa lutein cells in themselves do not have the 17α-hydroxylase or 17,20 lyase to produce androgens. [5] Once the corpus luteum regresses the remnant is known as corpus albicans. [12]
Each type of cell behaves differently in response to FSH. Theca interna cells express receptors for luteinizing hormone . LH induces the production of androgens by the theca cells, most notably androstendione, which are aromatized by granulosa cells to produce estrogens, primarily estradiol. Consequently, estrogen levels begin to rise.
Granulosa and theca cells continue to undergo mitosis concomitant with an increase in antrum volume. The Graaf follicle reaches its maximum diameter (20–22 mm) during ovulation. Antral follicles can attain a tremendous size that is hampered only by the availability of follicle stimulating hormone (FSH), on which it is dependent in this stage ...
Theca lutein cysts are lined by theca cells that may or may not be luteinized or have granulosa cells. They are usually bilateral and are filled with clear, straw-colored fluid. [ 7 ] Overall theca lutein cysts can be characterized by the luteniziation and hypertrophy of the theca interna layer.
The theca of the spinal cord is called the thecal sac, and intrathecal injections are made there or in the subarachnoid space of the skull. In human embryogenesis , the theca cells form a corpus luteum after a Graafian follicle has expelled its secondary oocyte arrested in second meiosis .